Re: [zfs-discuss] Mirrored raidz
> From: Darren J Moffat [mailto:darr...@opensolaris.org] > > It basically says that 'zfs send' gets a new '-b' option so "send back > properties", and 'zfs recv' gets a '-o' and '-x' option to allow > explicit set/ignore of properties in the stream. It also adds a '-r' > option for 'zfs set'. > > If/when the approved changes integrate it will look like: > > Based on the source code change history for onnv-gate it doesn't appear > to have integrated yet. Ahh. So, for now I'm sticking with "zpool get all" and "zfs get all" stored in a text file, unless somebody has a better idea... ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Mirrored raidz
On 28/07/2010 14:53, Edward Ned Harvey wrote: From: Richard Elling [mailto:richard.ell...@gmail.com] http://arc.opensolaris.org/caselog/PSARC/2010/193/mail Agree. This is a better solution because some configurable parameters are hidden from "zfs get all" Forgive me for not seeing it ... That link is extremely dense, and 34 pages long ... It basically says that 'zfs send' gets a new '-b' option so "send back properties", and 'zfs recv' gets a '-o' and '-x' option to allow explicit set/ignore of properties in the stream. It also adds a '-r' option for 'zfs set'. -b Sends only received property values whether or not they are overridden by local settings, but only if the dataset has ever been received. Use this option when you want 'zfs receive' to restore received properties backed up on the sent dataset and to avoid sending local settings that may have nothing to do with the source dataset, but only with how the data is backed up. Is there an option, that will capture properties better than "get all"? What is the suggested solution? If/when the approved changes integrate it will look like: zfs send -Rb foo | | zfs recv ... I don't see anything in "man zfs" ... but maybe it's only available in a later version of zfs? Based on the source code change history for onnv-gate it doesn't appear to have integrated yet. -- Darren J Moffat ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Mirrored raidz
> From: Richard Elling [mailto:richard.ell...@gmail.com] > > > http://arc.opensolaris.org/caselog/PSARC/2010/193/mail > > Agree. This is a better solution because some configurable parameters > are hidden from "zfs get all" Forgive me for not seeing it ... That link is extremely dense, and 34 pages long ... Is there an option, that will capture properties better than "get all"? What is the suggested solution? I don't see anything in "man zfs" ... but maybe it's only available in a later version of zfs? ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Mirrored raidz
On Jul 27, 2010, at 7:13 AM, Darren J Moffat wrote: > On 27/07/2010 13:28, Edward Ned Harvey wrote: >> The opposite is also true. If you have any special properties set on your >> main pool, they won't automatically be set on your receiving pool. So I >> personally recommend saving "zpool get all" and "zfs get all" into a txt >> file, and store it along with your backup media. So you have it available, >> if ever there were any confusion about it at all. > > PSARC/2010/193 defines a solution to solve that problem without having to > save away a copy of 'zfs get all'. > > http://arc.opensolaris.org/caselog/PSARC/2010/193/mail Agree. This is a better solution because some configurable parameters are hidden from "zfs get all" -- richard -- ZFS and performance consulting http://www.RichardElling.com ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Mirrored raidz
On 27/07/2010 13:28, Edward Ned Harvey wrote: The opposite is also true. If you have any special properties set on your main pool, they won't automatically be set on your receiving pool. So I personally recommend saving "zpool get all" and "zfs get all" into a txt file, and store it along with your backup media. So you have it available, if ever there were any confusion about it at all. PSARC/2010/193 defines a solution to solve that problem without having to save away a copy of 'zfs get all'. http://arc.opensolaris.org/caselog/PSARC/2010/193/mail -- Darren J Moffat ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Mirrored raidz
> From: zfs-discuss-boun...@opensolaris.org [mailto:zfs-discuss- > boun...@opensolaris.org] On Behalf Of Dav Banks This message: > How's that working for you? Seems like it would be as straightforward > as I was thinking - only possible. And this message: > Yeah, that's starting to sound like a fairly simple but equally robust > solution. That may be the final solution. Thanks! Didn't include any reference to what you were replying about. So I don't know which messages you were replying to when you sent those. If you're using the jive forums, and you wish to carry on dialogue with people who are using email, it's recommended to copy & paste what you're replying to, into your reply, so the recipients know what you're replying to. I am guessing you're replying to people saying "use zfs send" So my answer is: It works very well. Another feature, in favor of zfs send instead of mirrors, is the fact that you can have your backup media compressed while your main pool probably isn't. And so forth. The opposite is also true. If you have any special properties set on your main pool, they won't automatically be set on your receiving pool. So I personally recommend saving "zpool get all" and "zfs get all" into a txt file, and store it along with your backup media. So you have it available, if ever there were any confusion about it at all. ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Mirrored raidz
True! I don't need the same level of redundancy on the backup as the primary. -- 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] Mirrored raidz
Yeah, that's starting to sound like a fairly simple but equally robust solution. That may be the final solution. Thanks! -- 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] Mirrored raidz
Thanks Cindy - I've been looking for an admin guide! I'll play with the split command - sounds interesting. -- 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] Mirrored raidz
How's that working for you? Seems like it would be as straightforward as I was thinking - only possible. -- 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] Mirrored raidz
The reason for wanting raidz was to have some redundancy in the backup without the big hit on space that duplicating the data would have. The other issue is the switching process. More likely to have screwups if every week I, or someone else when I'm out, have to break and reset 24 mirrors instead of just one. I do need to look more at the copies property though. That could be useful in some other situations. -- 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] Mirrored raidz
> From: zfs-discuss-boun...@opensolaris.org [mailto:zfs-discuss- > boun...@opensolaris.org] On Behalf Of Ross Walker > > If that's the case why not create a second pool called 'backup' and > 'zfs send' periodically to the backup pool? +1 This is what I do. ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Mirrored raidz
It should be possible to do though if you are really serious about it. You can create two zfs zvols (volumes) which are hopefully in two different raidz-based zfs pools, and then create a new zfs pool using those two devices. The end result would be three zfs pools. It is probably not a wise idea to use this layered approach. A small follow-up is that creating pools from components of other pools can cause system deadlocks. One can make the zvols iSCSI targets and then attach them to the local initiator. This works and, indeed, it's a way to mirror storage across a network. -- Maurice Volaski, maurice.vola...@einstein.yu.edu Computing Support, Rose F. Kennedy Center Albert Einstein College of Medicine of Yeshiva University ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Mirrored raidz
On Mon, Jul 26 at 11:51, Dav Banks wrote: I wanted to test it as a backup solution. Maybe that's crazy in itself but I want to try it. Basically, once a week detach the 'backup' pool from the mirror, replace the drives, add the new raidz to the mirror and let it resilver and sit for a week. Since you're already "spending" the disk drives for this that get detached, it seems safer to me to just 'zfs send' to a minimal backup system, and remove the extra drives from your primary server. Less overhead and the scrub can validate your backup copy at whatever frequency you choose. You don't even need the same pool layout on the backup machine. Primary can be a stripe of mirrors, while your backup can be a wide raidz2 setup. --eric -- Eric D. Mudama edmud...@mail.bounceswoosh.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Mirrored raidz
On Mon, July 26, 2010 14:51, Dav Banks wrote: > I wanted to test it as a backup solution. Maybe that's crazy in itself but > I want to try it. > > Basically, once a week detach the 'backup' pool from the mirror, replace > the drives, add the new raidz to the mirror and let it resilver and sit > for a week. While a neat solution, I think you'd be better off using incremental send/recv functionality for backups. Having an online "backup" really isn't a true backup IMHO. It's too easy to fat finger something and then you're hosed as the change was replicated in real-time to both sides of the mirror (though this is mitigated a bit if you automatically take regular snapshots). Mirroring is (IMHO) for up time and insurance against hardware failure. Backups are /independent/ copies of data that are insurance something happening to your primary copy. You could do the same thing with a separate pool and send/recv, without taking the hit on write IOps from the second half of the mirror: basically async replication instead of synchronous. ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Mirrored raidz
On Jul 26, 2010, at 2:51 PM, Dav Banks wrote: > I wanted to test it as a backup solution. Maybe that's crazy in itself but I > want to try it. > > Basically, once a week detach the 'backup' pool from the mirror, replace the > drives, add the new raidz to the mirror and let it resilver and sit for a > week. If that's the case why not create a second pool called 'backup' and 'zfs send' periodically to the backup pool? -Ross ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Mirrored raidz
You might look at the zpool split feature, where you can split off the disks from a mirrored pool to create an identical pool, described here: http://hub.opensolaris.org/bin/view/Community+Group+zfs/docs ZFS Admin Guide, p. 87 Thanks, Cindy On 07/26/10 12:51, Dav Banks wrote: I wanted to test it as a backup solution. Maybe that's crazy in itself but I want to try it. Basically, once a week detach the 'backup' pool from the mirror, replace the drives, add the new raidz to the mirror and let it resilver and sit for a week. ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Mirrored raidz
On 26 Jul 2010, at 19:51, Dav Banks wrote: > I wanted to test it as a backup solution. Maybe that's crazy in itself but I > want to try it. > > Basically, once a week detach the 'backup' pool from the mirror, replace the > drives, add the new raidz to the mirror and let it resilver and sit for a > week. Why not do it the other way around? Create a pool which consists of mirrored pairs (or triples) of drives. You don't need raidz to make it appear that the pool is bigger and it will use disks in the pool appropriately. If you want to have more copies of data, set copies=2 and zfs will try to schedule writes across different mirrored pairs. Alex ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Mirrored raidz
I wanted to test it as a backup solution. Maybe that's crazy in itself but I want to try it. Basically, once a week detach the 'backup' pool from the mirror, replace the drives, add the new raidz to the mirror and let it resilver and sit for a week. -- 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] Mirrored raidz
A small follow-up is that creating pools from components of other pools can cause system deadlocks. This approach is not recommended. Thanks, Cindy On 07/26/10 12:19, Saxon, Will wrote: -Original Message- From: zfs-discuss-boun...@opensolaris.org [mailto:zfs-discuss-boun...@opensolaris.org] On Behalf Of Dav Banks Sent: Monday, July 26, 2010 2:02 PM To: zfs-discuss@opensolaris.org Subject: [zfs-discuss] Mirrored raidz This may have been covered somewhere but I couldn't find it. Is it possible to mirror two raidz vdevs? Like a RAID50 basically. RAID50 is not a mirror of RAID5s, but a stripset of RAID5s. RAID50 is analogous to multiple raidz vdevs in a single zpool. Mirrored RAID5s are not directly possible, as ZFS does not permit nested vdevs (i.e. a mirror vdev composed of raidz vdevs). I think you can make 2 separate zpools composed of single raidz vdevs, make zvols in those, then create a 3rd zpool with a mirror vdev of the zvols. -Will ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Mirrored raidz
On Mon, July 26, 2010 14:17, Dav Banks wrote: > Ah. Thanks! I should have said RAID51 - a mirror of RAID5 elements. > > Thanks for the info. Bummer that it can't be done. Out of curiosity, any particular reason why you want to do this? ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Mirrored raidz
> -Original Message- > From: zfs-discuss-boun...@opensolaris.org > [mailto:zfs-discuss-boun...@opensolaris.org] On Behalf Of Dav Banks > Sent: Monday, July 26, 2010 2:02 PM > To: zfs-discuss@opensolaris.org > Subject: [zfs-discuss] Mirrored raidz > > This may have been covered somewhere but I couldn't find it. > > Is it possible to mirror two raidz vdevs? Like a RAID50 basically. RAID50 is not a mirror of RAID5s, but a stripset of RAID5s. RAID50 is analogous to multiple raidz vdevs in a single zpool. Mirrored RAID5s are not directly possible, as ZFS does not permit nested vdevs (i.e. a mirror vdev composed of raidz vdevs). I think you can make 2 separate zpools composed of single raidz vdevs, make zvols in those, then create a 3rd zpool with a mirror vdev of the zvols. -Will ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Mirrored raidz
Ah. Thanks! I should have said RAID51 - a mirror of RAID5 elements. Thanks for the info. Bummer that it can't be done. -- 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] Mirrored raidz
On Mon, 26 Jul 2010, Dav Banks wrote: This may have been covered somewhere but I couldn't find it. Is it possible to mirror two raidz vdevs? Like a RAID50 basically. This config is not supported by zfs. It should be possible to do though if you are really serious about it. You can create two zfs zvols (volumes) which are hopefully in two different raidz-based zfs pools, and then create a new zfs pool using those two devices. The end result would be three zfs pools. It is probably not a wise idea to use this layered approach. Bob -- Bob Friesenhahn bfrie...@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/ GraphicsMagick Maintainer,http://www.GraphicsMagick.org/ ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Mirrored raidz
Hi, > Is it possible to mirror two raidz vdevs? Like a RAID50 basically. Raid 50 is striped... basically: zpool create tank raidz c0t0d0 c0t0d1 c0t0d2 raidz c1t0d0 c1t0d1 c0t0d2 Other than that, I believe it is not possible to create a mirrored pool from raidz vdevs Regards, Serge Fonville -- http://www.sergefonville.nl Convince Google!! They need to support Adsense over SSL https://www.google.com/adsense/support/bin/answer.py?hl=en&answer=10528 http://www.google.com/support/forum/p/AdSense/thread?tid=1884bc9310d9f923&hl=en ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
[zfs-discuss] Mirrored raidz
This may have been covered somewhere but I couldn't find it. Is it possible to mirror two raidz vdevs? Like a RAID50 basically. -- 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] Mirrored Raidz
On Oct 24, 2006, at 04:19, Roch wrote: Michel Kintz writes: Matthew Ahrens a écrit : Richard Elling - PAE wrote: Anthony Miller wrote: Hi, I've search the forums and not found any answer to the following. I have 2 JBOD arrays each with 4 disks. I want to create create a raidz on one array and have it mirrored to the other array. Today, the top level raid sets are assembled using dynamic striping. There is no option to assemble the sets with mirroring. Perhaps the ZFS team can enlighten us on their intentions in this area? Our thinking is that if you want more redundancy than RAID-Z, you should use RAID-Z with double parity, which provides more reliability and more usable storage than a mirror of RAID-Zs would. (Also, expressing "mirror of RAID-Zs" from the CLI would be a bit messy; you'd have to introduce parentheses in vdev descriptions or something.) It is not always a matter of more redundancy. In my customer's case, they have storage in 2 different rooms of their datacenter and want to mirror from one storage unit in one room to the other. So having in this case a combination of RAID-Z + Mirror makes sense in my mind or ? Michel. ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss you may let the storage export RAID-5 luns and let ZFS mirror those. Would that work ? -r they're JBOD arrays, so unless you're proposing the use of another volume manager i don't think that would work. as for the maximum redundancy in configurations, i think that Frank hit it with the mirroring of each drive component across the arrays and doing a simple stripe I just think it would be good to add the flexibility in zpool to: 1) raidz a set of mirrors 2) mirror a couple of raidz in certain environments you care more about multiple drive or array failures than anything else. Today you can do this with zvols, but I'm a little worried about how this would perform given the nested layering you have to introduce .. eg: # zpool create a1pool raidz c0t0d0 c0t1d0 c0t2d0 .. # zpool create a2pool raidz c1t0d0 c1t1d0 c1t2d0 .. # zfs create -V a1pool/vol # zfs create -V a2pool/vol # zpool create mzdata mirror /dev/zvol/dsk/a1pool/vol /dev/zvol/dsk/ a2pool/vol .je ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Mirrored Raidz
On Oct 24, 2006, at 4:56 AM, Michel Kintz wrote: It is not always a matter of more redundancy. In my customer's case, they have storage in 2 different rooms of their datacenter and want to mirror from one storage unit in one room to the other. So having in this case a combination of RAID-Z + Mirror makes sense in my mind or ? It /does/ make sense. Having a geographically diverse storage scenario like this is good, but changes the rules a bit, and in a way that you can't fully take advantage of by using only soft RAID such as ZFS or SVM. The missing link as you point out is the missing ability to mirror (within the ZFS) a RAIDZ vdev. To get around this, I just use hardware RAID5 on my separate arrays and use either ZFS or SVM mirroring between the two on the hosts. I have thought about this over the past several months, and believe that it's probably better this way rather doing it all in ZFS or SVM. /dale ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Mirrored Raidz
Michel Kintz writes: > Matthew Ahrens a écrit : > > > Richard Elling - PAE wrote: > > > >> Anthony Miller wrote: > >> > >>> Hi, > >>> > >>> I've search the forums and not found any answer to the following. > >>> > >>> I have 2 JBOD arrays each with 4 disks. > >>> > >>> I want to create create a raidz on one array and have it mirrored to > >>> the other array. > >> > >> > >> Today, the top level raid sets are assembled using dynamic striping. > >> There > >> is no option to assemble the sets with mirroring. Perhaps the ZFS > >> team can > >> enlighten us on their intentions in this area? > > > > > > Our thinking is that if you want more redundancy than RAID-Z, you > > should use RAID-Z with double parity, which provides more reliability > > and more usable storage than a mirror of RAID-Zs would. > > > > (Also, expressing "mirror of RAID-Zs" from the CLI would be a bit > > messy; you'd have to introduce parentheses in vdev descriptions or > > something.) > > It is not always a matter of more redundancy. > In my customer's case, they have storage in 2 different rooms of their > datacenter and want to mirror from one storage unit in one room to the > other. > So having in this case a combination of RAID-Z + Mirror makes sense in > my mind or ? > > Michel. > > > ___ > zfs-discuss mailing list > zfs-discuss@opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss you may let the storage export RAID-5 luns and let ZFS mirror those. Would that work ? -r ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Mirrored Raidz
Matthew Ahrens a écrit : Richard Elling - PAE wrote: Anthony Miller wrote: Hi, I've search the forums and not found any answer to the following. I have 2 JBOD arrays each with 4 disks. I want to create create a raidz on one array and have it mirrored to the other array. Today, the top level raid sets are assembled using dynamic striping. There is no option to assemble the sets with mirroring. Perhaps the ZFS team can enlighten us on their intentions in this area? Our thinking is that if you want more redundancy than RAID-Z, you should use RAID-Z with double parity, which provides more reliability and more usable storage than a mirror of RAID-Zs would. (Also, expressing "mirror of RAID-Zs" from the CLI would be a bit messy; you'd have to introduce parentheses in vdev descriptions or something.) It is not always a matter of more redundancy. In my customer's case, they have storage in 2 different rooms of their datacenter and want to mirror from one storage unit in one room to the other. So having in this case a combination of RAID-Z + Mirror makes sense in my mind or ? Michel. ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Mirrored Raidz
Richard Elling - PAE wrote: Anthony Miller wrote: Hi, I've search the forums and not found any answer to the following. I have 2 JBOD arrays each with 4 disks. I want to create create a raidz on one array and have it mirrored to the other array. Today, the top level raid sets are assembled using dynamic striping. There is no option to assemble the sets with mirroring. Perhaps the ZFS team can enlighten us on their intentions in this area? Our thinking is that if you want more redundancy than RAID-Z, you should use RAID-Z with double parity, which provides more reliability and more usable storage than a mirror of RAID-Zs would. (Also, expressing "mirror of RAID-Zs" from the CLI would be a bit messy; you'd have to introduce parentheses in vdev descriptions or something.) --matt ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Mirrored Raidz
Frank Cusack wrote: On October 20, 2006 8:43:03 AM -0700 Ed Gould <[EMAIL PROTECTED]> wrote: On Oct 20, 2006, at 0:48, Torrey McMahon wrote: Anthony Miller wrote: I want to create create a raidz on one array and have it mirrored to the other array. Do you think this will get you more availability compared to a simple mirror? I'm curious as to why you would want to do this. This configuration will survive the failure of one drive in either RAIDZ *plus* the failure of any number of drives (or the whole mirror) in the other. That may or may not be valuable enough to choose, but it will survive more failures than just a mirror. Yes, it will survive more failures (one more, I think), but will that deliver more availability? Especially at the (high) cost of performance of a raidz vs a stripe. Yes, RAID-Z+mirror (or RAID-5+1) will provide better availability than RAID-Z+dynamic_stripe (or RAID-5+0). It will also provide better MTTDL. Random, small iop read performance will be similar to a pair of mirrored disks. -- richard ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Mirrored Raidz
On October 20, 2006 8:43:03 AM -0700 Ed Gould <[EMAIL PROTECTED]> wrote: On Oct 20, 2006, at 0:48, Torrey McMahon wrote: Anthony Miller wrote: I want to create create a raidz on one array and have it mirrored to the other array. Do you think this will get you more availability compared to a simple mirror? I'm curious as to why you would want to do this. This configuration will survive the failure of one drive in either RAIDZ *plus* the failure of any number of drives (or the whole mirror) in the other. That may or may not be valuable enough to choose, but it will survive more failures than just a mirror. Yes, it will survive more failures (one more, I think), but will that deliver more availability? Especially at the (high) cost of performance of a raidz vs a stripe. I'm also very curious to hear the reasoning. -frank ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Mirrored Raidz
Anthony Miller wrote: Hi, I've search the forums and not found any answer to the following. I have 2 JBOD arrays each with 4 disks. I want to create create a raidz on one array and have it mirrored to the other array. Today, the top level raid sets are assembled using dynamic striping. There is no option to assemble the sets with mirroring. Perhaps the ZFS team can enlighten us on their intentions in this area? -- richard ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Mirrored Raidz
On Oct 20, 2006, at 0:48, Torrey McMahon wrote: Anthony Miller wrote: I want to create create a raidz on one array and have it mirrored to the other array. Do you think this will get you more availability compared to a simple mirror? I'm curious as to why you would want to do this. This configuration will survive the failure of one drive in either RAIDZ *plus* the failure of any number of drives (or the whole mirror) in the other. That may or may not be valuable enough to choose, but it will survive more failures than just a mirror. --Ed ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Mirrored Raidz
Anthony Miller wrote: Hi, I've search the forums and not found any answer to the following. I have 2 JBOD arrays each with 4 disks. I want to create create a raidz on one array and have it mirrored to the other array. Do you think this will get you more availability compared to a simple mirror? I'm curious as to why you would want to do this. ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Mirrored Raidz
On October 19, 2006 9:02:47 PM -0700 Anthony Miller <[EMAIL PROTECTED]> wrote: Hi, I've search the forums and not found any answer to the following. I have 2 JBOD arrays each with 4 disks. I want to create create a raidz on one array and have it mirrored to the other array. huh, why would you want raidz's instead of just stripes. since you're mirroring it anyway. zpool create mirror c0t0 c1t0 mirror c0t1 c1t1 ... which is like a raid10 (cf raid01) -frank ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
[zfs-discuss] Mirrored Raidz
Hi, I've search the forums and not found any answer to the following. I have 2 JBOD arrays each with 4 disks. I want to create create a raidz on one array and have it mirrored to the other array. I've tried various command variations, but none seem to create what I want. e.g. zpool create -f -m /export/data mzdata raidz c1t8d0 c1t9d0 c1t10d0 c1t11d0 mirror c2t8d0 c2t9d0 c1t10d0 Which created well, I'm not really sure. But what I want is something like: mzdataONLINE 0 0 0 mirror ONLINE 0 0 0 raidz ONLINE 0 0 0 c1t8d0 ONLINE 0 0 0 c1t9d0 ONLINE 0 0 0 c1t10d0 ONLINE 0 0 0 c1t11d0 ONLINE 0 0 0 raidzONLINE 0 0 0 c1t15d0 ONLINE 0 0 0 c1t14d0 ONLINE 0 0 0 c1t13d0 ONLINE 0 0 0 c1t13d0 ONLINE 0 0 0 thanks for any help or advice. _A_ This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
