Re: [zfs-discuss] Posible newbie question about space between zpool and zfs file systems
On Wed, Mar 17, 2010 at 11:23 AM, wrote: > > > >IMHO, what matters is that pretty much everything from the disk controller > >to the CPU and network interface is advertised in power-of-2 terms and > disks > >sit alone using power-of-10. And students are taught that computers work > >with bits and so everything is a power of 2. > > That is simply not true: > >Memory: power of 2(bytes) >Network: power of 10 (bits/s)) >Disk: power of 10 (bytes) >CPU Frequency: power of 10 (cycles/s) >SD/Flash/..: power of 10 (bytes) >Bus speed: power of 10 > > Main memory is the odd one out. > My bad on generalizing that information. Perhaps the software stack dealing with disks should be changed to use power-of-10. Unlikely too. -- Giovanni ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Posible newbie question about space between zpool and zfs file systems
On Wed, Mar 17, 2010 at 9:09 PM, Giovanni Tirloni wrote: > IMHO, what matters is that pretty much everything from the disk controller > to the CPU and network interface is advertised in power-of-2 terms and disks > sit alone using power-of-10. And students are taught that computers work > with bits and so everything is a power of 2. > Apparently someone wrote false information on Wikipedia [1]. [1] http://en.wikipedia.org/wiki/Data_rate_units#Examples -- O< ascii ribbon campaign - stop html mail - www.asciiribbon.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Posible newbie question about space between zpool and zfs file systems
>IMHO, what matters is that pretty much everything from the disk controller >to the CPU and network interface is advertised in power-of-2 terms and disks >sit alone using power-of-10. And students are taught that computers work >with bits and so everything is a power of 2. That is simply not true: Memory: power of 2(bytes) Network: power of 10 (bits/s)) Disk: power of 10 (bytes) CPU Frequency: power of 10 (cycles/s) SD/Flash/..: power of 10 (bytes) Bus speed: power of 10 Main memory is the odd one out. >Just last week I had to remind people that a 24-disk JBOD with 1TB disks >wouldn't provide 24TB of storage since disks show up as 931GB. Well some will say it's 24T :-) >It *is* an anomaly and I don't expect it to be fixed. > >Perhaps some disk vendor could add more bits to its drives and advertise a >"real 1TB disk" using power-of-2 and show how people are being misled by >other vendors that use power-of-10. Highly unlikely but would sure get some >respect from the storage community. You've not been misled unless you have your had in the sand for the last five to ten years. Casper ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Posible newbie question about space between zpool and zfs file systems
On Wed, Mar 17, 2010 at 9:34 AM, David Dyer-Bennet wrote: > On 3/16/2010 23:21, Erik Trimble wrote: > >> On 3/16/2010 8:29 PM, David Dyer-Bennet wrote: >> >>> On 3/16/2010 17:45, Erik Trimble wrote: >>> David Dyer-Bennet wrote: > On Tue, March 16, 2010 14:59, Erik Trimble wrote: > > Has there been a consideration by anyone to do a class-action lawsuit >> for false advertising on this? I know they now have to include the >> "1GB >> = 1,000,000,000 bytes" thing in their specs and somewhere on the box, >> but just because I say "1 L = 0.9 metric liters" somewhere on the box, >> it shouldn't mean that I should be able to avertise in huge letters "2 >> L >> bottle of Coke" on the outside of the package... >> > > I think "giga" is formally defined as a prefix meaning 10^9; that is, > the > definition the disk manufacturers are using is the standard metric one > and > very probably the one most people expect. There are international > standards for these things. > > I'm well aware of the history of power-of-two block and disk sizes in > computers (the first computers I worked with pre-dated that period); > but I > think we need to recognize that this is our own weird local usage of > terminology, and that we can't expect the rest of the world to change > to > our way of doing things. > That's RetConn-ing. The only reason the stupid GiB / GB thing came around in the past couple of years is that the disk drive manufacturers pushed SI to do it. Up until 5 years ago (or so), GigaByte meant a power of 2 to EVERYONE, not just us techies. I would hardly call 40+ years of using the various giga/mega/kilo prefixes as a power of 2 in computer science as non-authoritative. In fact, I would argue that the HD manufacturers don't have a leg to stand on - it's not like they were "outside" the field and used to the "standard" SI notation of powers of 10. Nope. They're inside the industry, used the powers-of-2 for decades, then suddenly decided to "modify" that meaning, as it served their marketing purposes. >>> >>> The SI meaning was first proposed in the 1920s, so far as I can tell. >>> Our entire history of special usage took place while the SI definition was >>> in place. We simply mis-used it. There was at the time no prefix for what >>> we actually wanted (not giga then, but mega), so we borrowed and repurposed >>> mega. >>> >>> Doesn't matter whether the "original" meaning of K/M/G was a >> power-of-10. What matters is internal usage in the industry. And that has >> been consistent with powers-of-2 for 40+ years. There has been NO outside >> understanding that GB = 1 billion bytes until the Storage Industry decided >> it wanted it that way. That's pretty much the definition of distorted >> advertising. >> > > That's simply not true. The first computer I programmed, an IBM 1620, was > routinely referred to as having "20K" of core. That meant 20,000 decimal > digits; not 20,480. The other two memory configurations were similarly > "40K" for 40,000 and "60K" for 60,000. The first computer I was *paid* for > programming, the 1401, had "8K" of core, and that was 8,000 locations, not > 8,192. This was right on 40 years ago (fall of 1969 when I started working > on the 1401). Yes, neither was brand new, but IBM was still leasing them to > customers (it came in configurations of 4k, 8k, 12k, and I think 16k; been a > while!). At this point in history it doesn't matter much who's right or wrong anymore. IMHO, what matters is that pretty much everything from the disk controller to the CPU and network interface is advertised in power-of-2 terms and disks sit alone using power-of-10. And students are taught that computers work with bits and so everything is a power of 2. Just last week I had to remind people that a 24-disk JBOD with 1TB disks wouldn't provide 24TB of storage since disks show up as 931GB. It *is* an anomaly and I don't expect it to be fixed. Perhaps some disk vendor could add more bits to its drives and advertise a "real 1TB disk" using power-of-2 and show how people are being misled by other vendors that use power-of-10. Highly unlikely but would sure get some respect from the storage community. -- Giovanni ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Posible newbie question about space between zpool and zfs file systems
On 3/16/2010 23:21, Erik Trimble wrote: On 3/16/2010 8:29 PM, David Dyer-Bennet wrote: On 3/16/2010 17:45, Erik Trimble wrote: David Dyer-Bennet wrote: On Tue, March 16, 2010 14:59, Erik Trimble wrote: Has there been a consideration by anyone to do a class-action lawsuit for false advertising on this? I know they now have to include the "1GB = 1,000,000,000 bytes" thing in their specs and somewhere on the box, but just because I say "1 L = 0.9 metric liters" somewhere on the box, it shouldn't mean that I should be able to avertise in huge letters "2 L bottle of Coke" on the outside of the package... I think "giga" is formally defined as a prefix meaning 10^9; that is, the definition the disk manufacturers are using is the standard metric one and very probably the one most people expect. There are international standards for these things. I'm well aware of the history of power-of-two block and disk sizes in computers (the first computers I worked with pre-dated that period); but I think we need to recognize that this is our own weird local usage of terminology, and that we can't expect the rest of the world to change to our way of doing things. That's RetConn-ing. The only reason the stupid GiB / GB thing came around in the past couple of years is that the disk drive manufacturers pushed SI to do it. Up until 5 years ago (or so), GigaByte meant a power of 2 to EVERYONE, not just us techies. I would hardly call 40+ years of using the various giga/mega/kilo prefixes as a power of 2 in computer science as non-authoritative. In fact, I would argue that the HD manufacturers don't have a leg to stand on - it's not like they were "outside" the field and used to the "standard" SI notation of powers of 10. Nope. They're inside the industry, used the powers-of-2 for decades, then suddenly decided to "modify" that meaning, as it served their marketing purposes. The SI meaning was first proposed in the 1920s, so far as I can tell. Our entire history of special usage took place while the SI definition was in place. We simply mis-used it. There was at the time no prefix for what we actually wanted (not giga then, but mega), so we borrowed and repurposed mega. Doesn't matter whether the "original" meaning of K/M/G was a power-of-10. What matters is internal usage in the industry. And that has been consistent with powers-of-2 for 40+ years. There has been NO outside understanding that GB = 1 billion bytes until the Storage Industry decided it wanted it that way. That's pretty much the definition of distorted advertising. That's simply not true. The first computer I programmed, an IBM 1620, was routinely referred to as having "20K" of core. That meant 20,000 decimal digits; not 20,480. The other two memory configurations were similarly "40K" for 40,000 and "60K" for 60,000. The first computer I was *paid* for programming, the 1401, had "8K" of core, and that was 8,000 locations, not 8,192. This was right on 40 years ago (fall of 1969 when I started working on the 1401). Yes, neither was brand new, but IBM was still leasing them to customers (it came in configurations of 4k, 8k, 12k, and I think 16k; been a while!). -- David Dyer-Bennet, d...@dd-b.net; http://dd-b.net/ Snapshots: http://dd-b.net/dd-b/SnapshotAlbum/data/ Photos: http://dd-b.net/photography/gallery/ Dragaera: http://dragaera.info ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Posible newbie question about space between zpool and zfs file systems
>Carson Gaspar wrote: >>> Not quite. >>> 11 x 10^12 =~ 10.004 x (1024^4). >>> >>> So, the 'zpool list' is right on, at "10T" available. >> >> Duh, I was doing GiB math (y = x * 10^9 / 2^20), not TiB math (y = x * >> 10^12 / 2^40). >> >> Thanks for the correction. >> >You're welcome. :-) > > >On a not-completely-on-topic note: > >Has there been a consideration by anyone to do a class-action lawsuit >for false advertising on this? I know they now have to include the "1GB >= 1,000,000,000 bytes" thing in their specs and somewhere on the box, >but just because I say "1 L = 0.9 metric liters" somewhere on the box, >it shouldn't mean that I should be able to avertise in huge letters "2 L >bottle of Coke" on the outside of the package... I think such attempts have been done and I think one was settled by Western Digital. https://www.wdc.com/settlement/docs/document20.htm This was in 2006. I was apparently part of the 'class' as I had a disk registered; I think they gave some software. See also: http://en.wikipedia.org/wiki/Binary_prefix Casper ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Posible newbie question about space between zpool and zfs file systems
Eric, in my understanding ( which I learned from more qualified people but I may be mistaken anyway ), whenever we discuss a transfer rate like x Mb/s, y GB/s or z PB/d, the M, G, T or P refers to the frequency and not to the data. 1 MB/s means "transfer bytes at 1 MHz", NOT "transfer megabytes at 1Hz" therefor its 1'000'000 B/s ( strictly speaking ) Of course usually some protocol overhead is much larger and so the small 1000:1024 difference is irrelevant anyway and can+will be neglected. -- Roland Am 17.03.2010 04:45, schrieb Erik Trimble: On 3/16/2010 4:23 PM, Roland Rambau wrote: Eric, careful: Am 16.03.2010 23:45, schrieb Erik Trimble: Up until 5 years ago (or so), GigaByte meant a power of 2 to EVERYONE, not just us techies. I would hardly call 40+ years of using the various giga/mega/kilo prefixes as a power of 2 in computer science as non-authoritative. How long does it take to transmit 1 TiB over a 1 GB/sec tranmission link, assuming no overhead ? See ? hth -- Roland I guess folks have gotten lazy all over. Actually, for networking, it's all "GigaBIT", but I get your meaning. Which is why it's all properly labeled "1Gb" Ethernet, not "1GB" ethernet. That said, I'm still under the impression that Giga = 1024^3 for networking, just like Mega = 1024^2. After all, it's 100Mbit Ethernet, which doesn't mean it runs at 100Mhz. That is, on Fast Ethernet, I should be sending a max 100 x 1024^2 BITS per second. Data amounts are (so far as I know universally) employing powers-of-2, while frequencies are done in powers-of-10. Thus, baud (for modems) is in powers-of-10, as are CPU/memory speeds. Memory (*RAM of all sorts), bus THROUGHPUT (i.e. PCI-E is in powers-of-2), networking throughput, and even graphics throughput is in powers-of-2. If they want to use powers-of-10, then use the actual "normal" names, like graphics performance ratings have done (i.e. 10 billion texels, not "10 Gigatexels". Take a look at Nvidia's product literature: http://www.nvidia.com/object/IO_11761.html It's just the storage vendors using the broken measurements. Bastards! -- Roland Rambau Server and Solution Architects Principal Field Technologist Global Systems Engineering Phone: +49-89-46008-2520 Mobile:+49-172-84 58 129 Fax: +49-89-46008- mailto:roland.ram...@sun.com Sitz der Gesellschaft: Sun Microsystems GmbH, Sonnenallee 1, D-85551 Kirchheim-Heimstetten Amtsgericht München: HRB 161028; Geschäftsführer: Thomas Schröder *** UNIX ** /bin/sh * FORTRAN ** ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Posible newbie question about space between zpool and zfs file systems
On 3/16/2010 8:29 PM, David Dyer-Bennet wrote: On 3/16/2010 17:45, Erik Trimble wrote: David Dyer-Bennet wrote: On Tue, March 16, 2010 14:59, Erik Trimble wrote: Has there been a consideration by anyone to do a class-action lawsuit for false advertising on this? I know they now have to include the "1GB = 1,000,000,000 bytes" thing in their specs and somewhere on the box, but just because I say "1 L = 0.9 metric liters" somewhere on the box, it shouldn't mean that I should be able to avertise in huge letters "2 L bottle of Coke" on the outside of the package... I think "giga" is formally defined as a prefix meaning 10^9; that is, the definition the disk manufacturers are using is the standard metric one and very probably the one most people expect. There are international standards for these things. I'm well aware of the history of power-of-two block and disk sizes in computers (the first computers I worked with pre-dated that period); but I think we need to recognize that this is our own weird local usage of terminology, and that we can't expect the rest of the world to change to our way of doing things. That's RetConn-ing. The only reason the stupid GiB / GB thing came around in the past couple of years is that the disk drive manufacturers pushed SI to do it. Up until 5 years ago (or so), GigaByte meant a power of 2 to EVERYONE, not just us techies. I would hardly call 40+ years of using the various giga/mega/kilo prefixes as a power of 2 in computer science as non-authoritative. In fact, I would argue that the HD manufacturers don't have a leg to stand on - it's not like they were "outside" the field and used to the "standard" SI notation of powers of 10. Nope. They're inside the industry, used the powers-of-2 for decades, then suddenly decided to "modify" that meaning, as it served their marketing purposes. The SI meaning was first proposed in the 1920s, so far as I can tell. Our entire history of special usage took place while the SI definition was in place. We simply mis-used it. There was at the time no prefix for what we actually wanted (not giga then, but mega), so we borrowed and repurposed mega. Doesn't matter whether the "original" meaning of K/M/G was a power-of-10. What matters is internal usage in the industry. And that has been consistent with powers-of-2 for 40+ years. There has been NO outside understanding that GB = 1 billion bytes until the Storage Industry decided it wanted it that way. That's pretty much the definition of distorted advertising. The issue here is getting what you paid for. Changing the meaning of a well-understood term to be something that NO ONE else has used in that context is pretty much the definition of false advertising. Put it another way: for all those folks in the UK, how would you like to buy a Hundredweight (cwt) of something, but only get 100 lbs actually delivered? The UK (Imperial) cwt = 112 lbs, while the US cwt = 100 lbs. Having some fine print on the package that said cwt=100lbs isn't going to fly with the British Advertising Board. So why should we allow the fine print of 1 GB = 1 billion bytes? It's the same redefinition of a common term to confuse and distort. I know what you mean about the disk manufacturers changing. And I'm sure they did it because it made their disks sound bigger for free, and that's clearly a marketing choice, and yes, it creates the problem that when the software reports the size it often doesn't agree with the manufacturer size. I just can't get up a good head of steam about this when they're using the prefix correctly and we're not, though. Problem is, they're NOT using it correctly. Language is domain-specific - that is, terms have context. A word can mean completely different things in different contexts, and it's not correct to say X = true meaning for a given word. In this case, historical usage PLUS /actual/ implementation usage indicates that K/M/G/T are powers of 2. In our context of computing, they've meant powers-of-2. It's also disingenuous for them to argue that "consumers" (i.e. non-technical people) didn't understand the usage of powers-of-2. To effectively argue that, they've have to have made the switch around the time that mass-consumer usage/retailing of computing was happening, which was (at best) 1990. Oops. 15 years later it isn't rational to argue that consumers don't understand the "technical" usage of the term. Bottom line is that it's a advertising scam. Promising one thing, and delivering another. That's what the truth-in-advertising laws are for. -- Erik Trimble Java System Support Mailstop: usca22-123 Phone: x17195 Santa Clara, CA ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Posible newbie question about space between zpool and zfs file systems
On 3/16/2010 4:23 PM, Roland Rambau wrote: Eric, careful: Am 16.03.2010 23:45, schrieb Erik Trimble: Up until 5 years ago (or so), GigaByte meant a power of 2 to EVERYONE, not just us techies. I would hardly call 40+ years of using the various giga/mega/kilo prefixes as a power of 2 in computer science as non-authoritative. How long does it take to transmit 1 TiB over a 1 GB/sec tranmission link, assuming no overhead ? See ? hth -- Roland I guess folks have gotten lazy all over. Actually, for networking, it's all "GigaBIT", but I get your meaning. Which is why it's all properly labeled "1Gb" Ethernet, not "1GB" ethernet. That said, I'm still under the impression that Giga = 1024^3 for networking, just like Mega = 1024^2. After all, it's 100Mbit Ethernet, which doesn't mean it runs at 100Mhz. That is, on Fast Ethernet, I should be sending a max 100 x 1024^2 BITS per second. Data amounts are (so far as I know universally) employing powers-of-2, while frequencies are done in powers-of-10. Thus, baud (for modems) is in powers-of-10, as are CPU/memory speeds. Memory (*RAM of all sorts), bus THROUGHPUT (i.e. PCI-E is in powers-of-2), networking throughput, and even graphics throughput is in powers-of-2. If they want to use powers-of-10, then use the actual "normal" names, like graphics performance ratings have done (i.e. 10 billion texels, not "10 Gigatexels". Take a look at Nvidia's product literature: http://www.nvidia.com/object/IO_11761.html It's just the storage vendors using the broken measurements. Bastards! -- Erik Trimble Java System Support Mailstop: usca22-123 Phone: x17195 Santa Clara, CA ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Posible newbie question about space between zpool and zfs file systems
On 3/16/2010 17:45, Erik Trimble wrote: David Dyer-Bennet wrote: On Tue, March 16, 2010 14:59, Erik Trimble wrote: Has there been a consideration by anyone to do a class-action lawsuit for false advertising on this? I know they now have to include the "1GB = 1,000,000,000 bytes" thing in their specs and somewhere on the box, but just because I say "1 L = 0.9 metric liters" somewhere on the box, it shouldn't mean that I should be able to avertise in huge letters "2 L bottle of Coke" on the outside of the package... I think "giga" is formally defined as a prefix meaning 10^9; that is, the definition the disk manufacturers are using is the standard metric one and very probably the one most people expect. There are international standards for these things. I'm well aware of the history of power-of-two block and disk sizes in computers (the first computers I worked with pre-dated that period); but I think we need to recognize that this is our own weird local usage of terminology, and that we can't expect the rest of the world to change to our way of doing things. That's RetConn-ing. The only reason the stupid GiB / GB thing came around in the past couple of years is that the disk drive manufacturers pushed SI to do it. Up until 5 years ago (or so), GigaByte meant a power of 2 to EVERYONE, not just us techies. I would hardly call 40+ years of using the various giga/mega/kilo prefixes as a power of 2 in computer science as non-authoritative. In fact, I would argue that the HD manufacturers don't have a leg to stand on - it's not like they were "outside" the field and used to the "standard" SI notation of powers of 10. Nope. They're inside the industry, used the powers-of-2 for decades, then suddenly decided to "modify" that meaning, as it served their marketing purposes. The SI meaning was first proposed in the 1920s, so far as I can tell. Our entire history of special usage took place while the SI definition was in place. We simply mis-used it. There was at the time no prefix for what we actually wanted (not giga then, but mega), so we borrowed and repurposed mega. I know what you mean about the disk manufacturers changing. And I'm sure they did it because it made their disks sound bigger for free, and that's clearly a marketing choice, and yes, it creates the problem that when the software reports the size it often doesn't agree with the manufacturer size. I just can't get up a good head of steam about this when they're using the prefix correctly and we're not, though. -- David Dyer-Bennet, d...@dd-b.net; http://dd-b.net/ Snapshots: http://dd-b.net/dd-b/SnapshotAlbum/data/ Photos: http://dd-b.net/photography/gallery/ Dragaera: http://dragaera.info ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Posible newbie question about space between zpool and zfs file systems
Eric, careful: Am 16.03.2010 23:45, schrieb Erik Trimble: Up until 5 years ago (or so), GigaByte meant a power of 2 to EVERYONE, not just us techies. I would hardly call 40+ years of using the various giga/mega/kilo prefixes as a power of 2 in computer science as non-authoritative. How long does it take to transmit 1 TiB over a 1 GB/sec tranmission link, assuming no overhead ? See ? hth -- Roland -- Roland Rambau Server and Solution Architects Principal Field Technologist Global Systems Engineering Phone: +49-89-46008-2520 Mobile:+49-172-84 58 129 Fax: +49-89-46008- mailto:roland.ram...@sun.com Sitz der Gesellschaft: Sun Microsystems GmbH, Sonnenallee 1, D-85551 Kirchheim-Heimstetten Amtsgericht München: HRB 161028; Geschäftsführer: Thomas Schröder *** UNIX ** /bin/sh * FORTRAN ** ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Posible newbie question about space between zpool and zfs file systems
The reason why there is not more uproar is that cost per data unit is dwindling while the gap resulting from this marketing trick is increasing. I remember a case a German broadcaster filed against a system integrator in the age of the 4 GB SCSI drive. This was in the mid-90s. Regards, Tonmaus -- This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Posible newbie question about space between zpool and zfs file systems
On Wed, Mar 17, 2010 at 5:45 AM, Erik Trimble wrote: > Up until 5 years ago (or so), GigaByte meant a power of 2 to EVERYONE, not > just us techies. I would hardly call 40+ years of using the various > giga/mega/kilo prefixes as a power of 2 in computer science as > non-authoritative. In fact, I would argue that the HD manufacturers don't > have a leg to stand on - it's not like they were "outside" the field and > used to the "standard" SI notation of powers of 10. Nope. They're inside > the industry, used the powers-of-2 for decades, then suddenly decided to > "modify" that meaning, as it served their marketing purposes. > it's probably just me, but I always raged when calculating anything using imperial units, * binary bytes and time. -- O< ascii ribbon campaign - stop html mail - www.asciiribbon.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Posible newbie question about space between zpool and zfs file systems
Erik Trimble wrote: Tonmaus wrote: Has there been a consideration by anyone to do a class-action lawsuit for false advertising on this? I know they now have to include the "1GB = 1,000,000,000 bytes" thing in their specs and somewhere on the box, but just because I say "1 L = 0.9 metric liters" somewhere on the box, it shouldn't mean that I should be able to avertise in huge letters "2 L bottle of Coke" on the outside of the package... If I am not completely mistaken, 1^n/1,024^n is converging against 0 for n vs infinite. That is certainly an unwarranted facilitation of Kryder's law for very large storage devices. Regards, Tonmaus well, that's true, even if it is Limit n->infinity for [1000^n / 1024^n]it's still 0. :-) Actually, my old Calculus teacher would be disappointed in me. It's Lim n->infinity ( 1000^n / (2^10)^n) or: Lim n->infinity (1000^n / 2^10n) As Tonmaus pointed out, it all still trends to 0. Now that little bit of pedantic anal calculus-izing is over, back to our regularly schedule madness. -- Erik Trimble Java System Support Mailstop: usca22-123 Phone: x17195 Santa Clara, CA ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Posible newbie question about space between zpool and zfs file systems
Tonmaus wrote: Has there been a consideration by anyone to do a class-action lawsuit for false advertising on this? I know they now have to include the "1GB = 1,000,000,000 bytes" thing in their specs and somewhere on the box, but just because I say "1 L = 0.9 metric liters" somewhere on the box, it shouldn't mean that I should be able to avertise in huge letters "2 L bottle of Coke" on the outside of the package... If I am not completely mistaken, 1^n/1,024^n is converging against 0 for n vs infinite. That is certainly an unwarranted facilitation of Kryder's law for very large storage devices. Regards, Tonmaus well, that's true, even if it is Limit n->infinity for [1000^n / 1024^n]it's still 0. :-) But seriously, you lose 2.3% per prefix. Right now, we're up to almost a 10% difference at TB. In 10 years for Petabyte, we're at over 11% loss. In 20 years, when Exabyte drives (or whatever storage is on) are common, that's almost 15% loss. Frankly, I'm starting to see an analog with Nautical Miles vs Statue Miles. -- Erik Trimble Java System Support Mailstop: usca22-123 Phone: x17195 Santa Clara, CA Timezone: US/Pacific (GMT-0800) ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Posible newbie question about space between zpool and zfs file systems
David Dyer-Bennet wrote: On Tue, March 16, 2010 14:59, Erik Trimble wrote: Has there been a consideration by anyone to do a class-action lawsuit for false advertising on this? I know they now have to include the "1GB = 1,000,000,000 bytes" thing in their specs and somewhere on the box, but just because I say "1 L = 0.9 metric liters" somewhere on the box, it shouldn't mean that I should be able to avertise in huge letters "2 L bottle of Coke" on the outside of the package... I think "giga" is formally defined as a prefix meaning 10^9; that is, the definition the disk manufacturers are using is the standard metric one and very probably the one most people expect. There are international standards for these things. I'm well aware of the history of power-of-two block and disk sizes in computers (the first computers I worked with pre-dated that period); but I think we need to recognize that this is our own weird local usage of terminology, and that we can't expect the rest of the world to change to our way of doing things. That's RetConn-ing. The only reason the stupid GiB / GB thing came around in the past couple of years is that the disk drive manufacturers pushed SI to do it. Up until 5 years ago (or so), GigaByte meant a power of 2 to EVERYONE, not just us techies. I would hardly call 40+ years of using the various giga/mega/kilo prefixes as a power of 2 in computer science as non-authoritative. In fact, I would argue that the HD manufacturers don't have a leg to stand on - it's not like they were "outside" the field and used to the "standard" SI notation of powers of 10. Nope. They're inside the industry, used the powers-of-2 for decades, then suddenly decided to "modify" that meaning, as it served their marketing purposes. Note that NOBODY else in the computer industry does this in their marketing materials - if it's such a standard, why on earth don't the DRAM chip makers support (and market) it that way? The various Mhz/Ghz notations are powers-of-10, but they've always been that way, and more importantly, are defined by the OSes and other software as being that way. HD capacities are an anomaly, and it's purely marketing smooze. They should get smacked hard again on this. It would be one thing if it was never seen (or only by super-nerds like us), but for the average consumer, when they buy that nice shiny Dell with an advertised 1TB disk, then boot to Windows 7, why does Windows then say that their C drive is only 900GB in size? How is that /not/ deceptive marketing? -- Erik Trimble Java System Support Mailstop: usca22-123 Phone: x17195 Santa Clara, CA Timezone: US/Pacific (GMT-0800) ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Posible newbie question about space between zpool and zfs file systems
> Has there been a consideration by anyone to do a > class-action lawsuit > for false advertising on this? I know they now have > to include the "1GB > = 1,000,000,000 bytes" thing in their specs and > somewhere on the box, > but just because I say "1 L = 0.9 metric liters" > somewhere on the box, > it shouldn't mean that I should be able to avertise > in huge letters "2 L > bottle of Coke" on the outside of the package... If I am not completely mistaken, 1^n/1,024^n is converging against 0 for n vs infinite. That is certainly an unwarranted facilitation of Kryder's law for very large storage devices. Regards, Tonmaus -- This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Posible newbie question about space between zpool and zfs file systems
On Tue, March 16, 2010 14:59, Erik Trimble wrote: > > Has there been a consideration by anyone to do a class-action lawsuit > for false advertising on this? I know they now have to include the "1GB > = 1,000,000,000 bytes" thing in their specs and somewhere on the box, > but just because I say "1 L = 0.9 metric liters" somewhere on the box, > it shouldn't mean that I should be able to avertise in huge letters "2 L > bottle of Coke" on the outside of the package... I think "giga" is formally defined as a prefix meaning 10^9; that is, the definition the disk manufacturers are using is the standard metric one and very probably the one most people expect. There are international standards for these things. I'm well aware of the history of power-of-two block and disk sizes in computers (the first computers I worked with pre-dated that period); but I think we need to recognize that this is our own weird local usage of terminology, and that we can't expect the rest of the world to change to our way of doing things. -- David Dyer-Bennet, d...@dd-b.net; http://dd-b.net/ Snapshots: http://dd-b.net/dd-b/SnapshotAlbum/data/ Photos: http://dd-b.net/photography/gallery/ Dragaera: http://dragaera.info ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Posible newbie question about space between zpool and zfs file systems
Carson Gaspar wrote: Not quite. 11 x 10^12 =~ 10.004 x (1024^4). So, the 'zpool list' is right on, at "10T" available. Duh, I was doing GiB math (y = x * 10^9 / 2^20), not TiB math (y = x * 10^12 / 2^40). Thanks for the correction. You're welcome. :-) On a not-completely-on-topic note: Has there been a consideration by anyone to do a class-action lawsuit for false advertising on this? I know they now have to include the "1GB = 1,000,000,000 bytes" thing in their specs and somewhere on the box, but just because I say "1 L = 0.9 metric liters" somewhere on the box, it shouldn't mean that I should be able to avertise in huge letters "2 L bottle of Coke" on the outside of the package... -- Erik Trimble Java System Support Mailstop: usca22-123 Phone: x17195 Santa Clara, CA ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Posible newbie question about space between zpool and zfs file systems
On 15 Mar 2010, at 23:03, Tonmaus wrote: Hi Cindy, trying to reproduce this For a RAIDZ pool, the zpool list command identifies the "inflated" space for the storage pool, which is the physical available space without an accounting for redundancy overhead. The zfs list command identifies how much actual pool space is available to the file systems. I am lacking 1 TB on my pool: u...@filemeister:~$ zpool list daten NAMESIZE ALLOC FREECAP DEDUP HEALTH ALTROOT daten10T 3,71T 6,29T37% 1.00x ONLINE - u...@filemeister:~$ zpool status daten pool: daten state: ONLINE scrub: none requested config: NAME STATE READ WRITE CKSUM daten ONLINE 0 0 0 raidz2-0ONLINE 0 0 0 c10t2d0 ONLINE 0 0 0 c10t3d0 ONLINE 0 0 0 c10t4d0 ONLINE 0 0 0 c10t5d0 ONLINE 0 0 0 c10t6d0 ONLINE 0 0 0 c10t7d0 ONLINE 0 0 0 c10t8d0 ONLINE 0 0 0 c10t9d0 ONLINE 0 0 0 c11t18d0 ONLINE 0 0 0 c11t19d0 ONLINE 0 0 0 c11t20d0 ONLINE 0 0 0 spares c11t21d0AVAIL errors: No known data errors u...@filemeister:~$ zfs list daten NAMEUSED AVAIL REFER MOUNTPOINT daten 3,01T 4,98T 110M /daten I am counting 11 disks 1 TB each in a raidz2 pool. This is 11 TB gross capacity, and 9 TB net. Zpool is however stating 10 TB and zfs is stating 8TB. The difference between net and gross is correct, but where is the capacity from the 11th disk going? Regards, Tonmaus This is because 1TB is not 1TB. The 1TB on your disk label means 10^12 bytes, while 1TB in the OS means (2^10)^4 = 1024^4 bytes. 11*(1000**4)/(1024.0**4) => 10.0044417195022 So your 11 "disk label" TB are 10 "OS" TB. Fun, isn't it? Best regards, Stefan ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Posible newbie question about space between zpool and zfs file systems
Someone wrote (I haven't seen the mail, only the unattributed quote): My guess is unit conversion and rounding. Your pool has 11 base 10 TB, which is 10.2445 base 2 TiB. Likewise your fs has 9 base 10 TB, which is 8.3819 base 2 TiB. Not quite. 11 x 10^12 =~ 10.004 x (1024^4). So, the 'zpool list' is right on, at "10T" available. Duh, I was doing GiB math (y = x * 10^9 / 2^20), not TiB math (y = x * 10^12 / 2^40). Thanks for the correction. -- Carson ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Posible newbie question about space between zpool and zfs file systems
> My guess is unit conversion and rounding. Your pool > has 11 base 10 TB, > which is 10.2445 base 2 TiB. > > Likewise your fs has 9 base 10 TB, which is 8.3819 > base 2 TiB. > Not quite. > > 11 x 10^12 =~ 10.004 x (1024^4). > > So, the 'zpool list' is right on, at "10T" available. Duh! I completely forgot about this. Thanks for the heads-up. Tonmaus -- This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Posible newbie question about space between zpool and zfs file systems
On Mon, 2010-03-15 at 15:40 -0700, Carson Gaspar wrote: > Tonmaus wrote: > > > I am lacking 1 TB on my pool: > > > > u...@filemeister:~$ zpool list daten NAMESIZE ALLOC FREE > > CAP DEDUP HEALTH ALTROOT daten10T 3,71T 6,29T37% 1.00x > > ONLINE - u...@filemeister:~$ zpool status daten pool: daten state: > > ONLINE scrub: none requested config: > > > > NAME STATE READ WRITE CKSUM daten ONLINE 0 > > 0 0 raidz2-0ONLINE 0 0 0 c10t2d0 ONLINE > > 0 0 0 c10t3d0 ONLINE 0 0 0 c10t4d0 ONLINE > > 0 0 0 c10t5d0 ONLINE 0 0 0 c10t6d0 ONLINE > > 0 0 0 c10t7d0 ONLINE 0 0 0 c10t8d0 ONLINE > > 0 0 0 c10t9d0 ONLINE 0 0 0 c11t18d0 ONLINE > > 0 0 0 c11t19d0 ONLINE 0 0 0 c11t20d0 ONLINE > > 0 0 0 spares c11t21d0AVAIL > > > > errors: No known data errors u...@filemeister:~$ zfs list daten NAME > > USED AVAIL REFER MOUNTPOINT daten 3,01T 4,98T 110M /daten > > > > I am counting 11 disks 1 TB each in a raidz2 pool. This is 11 TB > > gross capacity, and 9 TB net. Zpool is however stating 10 TB and zfs > > is stating 8TB. The difference between net and gross is correct, but > > where is the capacity from the 11th disk going? > > My guess is unit conversion and rounding. Your pool has 11 base 10 TB, > which is 10.2445 base 2 TiB. > > Likewise your fs has 9 base 10 TB, which is 8.3819 base 2 TiB. Not quite. 11 x 10^12 =~ 10.004 x (1024^4). So, the 'zpool list' is right on, at "10T" available. For the 'zfs list', remember there is a slight overhead for filesystem formatting. So, instead of 9 x 10^12 =~ 8.185 x (1024^4) it shows 7.99TB usable. The roughly 200GB is the overhead. (or, about 3%). -- Erik Trimble Java System Support Mailstop: usca22-123 Phone: x17195 Santa Clara, CA Timezone: US/Pacific (GMT-0800) ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Posible newbie question about space between zpool and zfs file systems
On Mon, 2010-03-15 at 15:03 -0700, Tonmaus wrote: > Hi Cindy, > trying to reproduce this > > > For a RAIDZ pool, the zpool list command identifies > > the "inflated" space > > for the storage pool, which is the physical available > > space without an > > accounting for redundancy overhead. > > > > The zfs list command identifies how much actual pool > > space is available > > to the file systems. > > I am lacking 1 TB on my pool: > > u...@filemeister:~$ zpool list daten > NAMESIZE ALLOC FREECAP DEDUP HEALTH ALTROOT > daten10T 3,71T 6,29T37% 1.00x ONLINE - > u...@filemeister:~$ zpool status daten > pool: daten > state: ONLINE > scrub: none requested > config: > > NAME STATE READ WRITE CKSUM > daten ONLINE 0 0 0 > raidz2-0ONLINE 0 0 0 > c10t2d0 ONLINE 0 0 0 > c10t3d0 ONLINE 0 0 0 > c10t4d0 ONLINE 0 0 0 > c10t5d0 ONLINE 0 0 0 > c10t6d0 ONLINE 0 0 0 > c10t7d0 ONLINE 0 0 0 > c10t8d0 ONLINE 0 0 0 > c10t9d0 ONLINE 0 0 0 > c11t18d0 ONLINE 0 0 0 > c11t19d0 ONLINE 0 0 0 > c11t20d0 ONLINE 0 0 0 > spares > c11t21d0AVAIL > > errors: No known data errors > u...@filemeister:~$ zfs list daten > NAMEUSED AVAIL REFER MOUNTPOINT > daten 3,01T 4,98T 110M /daten > > I am counting 11 disks 1 TB each in a raidz2 pool. This is 11 TB gross > capacity, and 9 TB net. Zpool is however stating 10 TB and zfs is stating > 8TB. The difference between net and gross is correct, but where is the > capacity from the 11th disk going? > > Regards, > > Tonmaus 1TB disks aren't a terabyte. Remember, the storage industry uses powers of 10, not 2. it's annoying. For each GB, you lose 7% in actual space computation. For each TB, it's about 9%. So, your "1TB" of is actually about 931 GB. 'zfs list' is going to report in actual powers-of-2, just like df. In my case, I have a 12 x 1TB configuration, and zfs list shows: # zpool list NAMESIZE USED AVAILCAP HEALTH ALTROOT array2540 10.9T 5.46T 5.41T50% ONLINE - Likewise: # zfs list NAMEUSED AVAIL REFER MOUNTPOINT array2540 4.53T 4.34T 80.4M /data So, here's the math: 1 "storage TB" = 1e12 / (1024^3) = 931 actual GB 931 GB x 12 = 11,172 GB but, 1TB = 1024 GB so: 931 GB x 12 / (1024) = 10.9TB. Quick Math: 1 TB of advertised space = 0.91 TB of real space 1 GB of advertised space = 0.93 GB of real space -- Erik Trimble Java System Support Mailstop: usca22-123 Phone: x17195 Santa Clara, CA Timezone: US/Pacific (GMT-0800) ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Posible newbie question about space between zpool and zfs file systems
Tonmaus wrote: I am lacking 1 TB on my pool: u...@filemeister:~$ zpool list daten NAMESIZE ALLOC FREE CAP DEDUP HEALTH ALTROOT daten10T 3,71T 6,29T37% 1.00x ONLINE - u...@filemeister:~$ zpool status daten pool: daten state: ONLINE scrub: none requested config: NAME STATE READ WRITE CKSUM daten ONLINE 0 0 0 raidz2-0ONLINE 0 0 0 c10t2d0 ONLINE 0 0 0 c10t3d0 ONLINE 0 0 0 c10t4d0 ONLINE 0 0 0 c10t5d0 ONLINE 0 0 0 c10t6d0 ONLINE 0 0 0 c10t7d0 ONLINE 0 0 0 c10t8d0 ONLINE 0 0 0 c10t9d0 ONLINE 0 0 0 c11t18d0 ONLINE 0 0 0 c11t19d0 ONLINE 0 0 0 c11t20d0 ONLINE 0 0 0 spares c11t21d0AVAIL errors: No known data errors u...@filemeister:~$ zfs list daten NAME USED AVAIL REFER MOUNTPOINT daten 3,01T 4,98T 110M /daten I am counting 11 disks 1 TB each in a raidz2 pool. This is 11 TB gross capacity, and 9 TB net. Zpool is however stating 10 TB and zfs is stating 8TB. The difference between net and gross is correct, but where is the capacity from the 11th disk going? My guess is unit conversion and rounding. Your pool has 11 base 10 TB, which is 10.2445 base 2 TiB. Likewise your fs has 9 base 10 TB, which is 8.3819 base 2 TiB. -- Carson ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Posible newbie question about space between zpool and zfs file systems
Hi Cindy, trying to reproduce this > For a RAIDZ pool, the zpool list command identifies > the "inflated" space > for the storage pool, which is the physical available > space without an > accounting for redundancy overhead. > > The zfs list command identifies how much actual pool > space is available > to the file systems. I am lacking 1 TB on my pool: u...@filemeister:~$ zpool list daten NAMESIZE ALLOC FREECAP DEDUP HEALTH ALTROOT daten10T 3,71T 6,29T37% 1.00x ONLINE - u...@filemeister:~$ zpool status daten pool: daten state: ONLINE scrub: none requested config: NAME STATE READ WRITE CKSUM daten ONLINE 0 0 0 raidz2-0ONLINE 0 0 0 c10t2d0 ONLINE 0 0 0 c10t3d0 ONLINE 0 0 0 c10t4d0 ONLINE 0 0 0 c10t5d0 ONLINE 0 0 0 c10t6d0 ONLINE 0 0 0 c10t7d0 ONLINE 0 0 0 c10t8d0 ONLINE 0 0 0 c10t9d0 ONLINE 0 0 0 c11t18d0 ONLINE 0 0 0 c11t19d0 ONLINE 0 0 0 c11t20d0 ONLINE 0 0 0 spares c11t21d0AVAIL errors: No known data errors u...@filemeister:~$ zfs list daten NAMEUSED AVAIL REFER MOUNTPOINT daten 3,01T 4,98T 110M /daten I am counting 11 disks 1 TB each in a raidz2 pool. This is 11 TB gross capacity, and 9 TB net. Zpool is however stating 10 TB and zfs is stating 8TB. The difference between net and gross is correct, but where is the capacity from the 11th disk going? Regards, Tonmaus -- This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Posible newbie question about space between zpool and zfs file systems
Yeah, this threw me. A 3 disk RAID-Z2 doesn't make sense, because at a redundancy level, RAID-Z2 looks like RAID 6. That is, there are 2 levels of parity for the data. Out of 3 disks, the equivalent of 2 disks will be used to store redundancy (parity) data and only 1 disk equivalent will store actual data. This is what others might term a "degenerate case of 3-way mirroring", except with a lot more computational overhead since we're performing 2 parity calculations. I'm curious what the purpose of creating a 3 disk RAID-Z2 pool is/was? (For my own personal edification. Maybe there is something for me to learn from this example.) Aside: Does ZFS actually create the pool as a 3-way mirror, given that this configuration is effectively the same? This is a question for any of the ZFS team who may be reading but I'm curious now. On Mon, Mar 15, 2010 at 10:38, Michael Hassey wrote: > Sorry if this is too basic - > > So I have a single zpool in addition to the rpool, called xpool. > > NAMESIZE USED AVAILCAP HEALTH ALTROOT > rpool 136G 109G 27.5G79% ONLINE - > xpool 408G 171G 237G42% ONLINE - > > I have 408 in the pool, am using 171 leaving me 237 GB. > > The pool is built up as; > > pool: xpool > state: ONLINE > scrub: none requested > config: > >NAMESTATE READ WRITE CKSUM >xpool ONLINE 0 0 0 > raidz2ONLINE 0 0 0 >c8t1d0 ONLINE 0 0 0 >c8t2d0 ONLINE 0 0 0 >c8t3d0 ONLINE 0 0 0 > > errors: No known data errors > > > But - and here is the question - > > Creating file systems on it, and the file systems in play report only 76GB > of space free > > <<<>> > > xpool/zones/logserver/ROOT/zbe 975M 76.4G 975M legacy > xpool/zones/openxsrvr 2.22G 76.4G 21.9K > /export/zones/openxsrvr > xpool/zones/openxsrvr/ROOT2.22G 76.4G 18.9K legacy > xpool/zones/openxsrvr/ROOT/zbe2.22G 76.4G 2.22G legacy > xpool/zones/puggles241M 76.4G 21.9K > /export/zones/puggles > xpool/zones/puggles/ROOT 241M 76.4G 18.9K legacy > xpool/zones/puggles/ROOT/zbe 241M 76.4G 241M legacy > xpool/zones/reposerver 299M 76.4G 21.9K > /export/zones/reposerver > > > So my question is, where is the space from xpool being used? or is it? > > > Thanks for reading. > > Mike. > -- > This message posted from opensolaris.org > ___ > zfs-discuss mailing list > zfs-discuss@opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss > -- "You can choose your friends, you can choose the deals." - Equity Private "If Linux is faster, it's a Solaris bug." - Phil Harman Blog - http://whatderass.blogspot.com/ Twitter - @khyron4eva ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Posible newbie question about space between zpool and zfs file systems
Hi Michael, For a RAIDZ pool, the zpool list command identifies the "inflated" space for the storage pool, which is the physical available space without an accounting for redundancy overhead. The zfs list command identifies how much actual pool space is available to the file systems. See the example of a RAIDZ-2 pool created below with 3 44 GB disks. The total pool capacity reported by zpool list is 134 GB. The amount of pool space that is available to the file systems is 43.8 GB due to RAIDZ-2 redundancy overhead. See this FAQ section for more information. http://hub.opensolaris.org/bin/view/Community+Group+zfs/faq#HZFSAdministrationQuestions Why doesn't the space that is reported by the zpool list command and the zfs list command match? Although this site is dog-slow for me today... Thanks, Cindy # zpool create xpool raidz2 c3t40d0 c3t40d1 c3t40d2 # zpool list xpool NAMESIZE USED AVAILCAP HEALTH ALTROOT xpool 134G 234K 134G 0% ONLINE - # zfs list xpool NAMEUSED AVAIL REFER MOUNTPOINT xpool 73.2K 43.8G 20.9K /xpool On 03/15/10 08:38, Michael Hassey wrote: Sorry if this is too basic - So I have a single zpool in addition to the rpool, called xpool. NAMESIZE USED AVAILCAP HEALTH ALTROOT rpool 136G 109G 27.5G79% ONLINE - xpool 408G 171G 237G42% ONLINE - I have 408 in the pool, am using 171 leaving me 237 GB. The pool is built up as; pool: xpool state: ONLINE scrub: none requested config: NAMESTATE READ WRITE CKSUM xpool ONLINE 0 0 0 raidz2ONLINE 0 0 0 c8t1d0 ONLINE 0 0 0 c8t2d0 ONLINE 0 0 0 c8t3d0 ONLINE 0 0 0 errors: No known data errors But - and here is the question - Creating file systems on it, and the file systems in play report only 76GB of space free <<<>> xpool/zones/logserver/ROOT/zbe 975M 76.4G 975M legacy xpool/zones/openxsrvr 2.22G 76.4G 21.9K /export/zones/openxsrvr xpool/zones/openxsrvr/ROOT2.22G 76.4G 18.9K legacy xpool/zones/openxsrvr/ROOT/zbe2.22G 76.4G 2.22G legacy xpool/zones/puggles241M 76.4G 21.9K /export/zones/puggles xpool/zones/puggles/ROOT 241M 76.4G 18.9K legacy xpool/zones/puggles/ROOT/zbe 241M 76.4G 241M legacy xpool/zones/reposerver 299M 76.4G 21.9K /export/zones/reposerver So my question is, where is the space from xpool being used? or is it? Thanks for reading. Mike. ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss