Re: [zfs-discuss] Server with 4 drives, how to configure ZFS?
Actually, you do want /usr and much of /var on the root pool, they are integral parts of the svc:/filesystem/local needed to bring up your system to a useable state (regardless of whether the other pools are working or not). Ok. I have my feelings on that topic but they may not be as relevant for ZFS. It may be because I tried to avoid single points of failure on other systems with techniques that don't map to ZFS or Solaris. I believe I can bring up several OS without /usr or /var although they complain they will work. But I'll take your point here. Depending on the OS versions, you can do manual data migrations to separate datasets of the root pool, in order to keep some data common between OE's or to enforce different quotas or compression rules. For example, on SXCE and Solaris 10 (but not on oi_148a) we successfully splice out many filesystems in such a layout (the example below also illustrates multiple OEs): Thanks, I have done similar things but I didn't know if they were approved. And you can not boot from any pool other than a mirror or a single drive. Rationale: a single BIOS device must be sufficient to boot the system and contain all the data needed to boot. Definitely important fact here. Thanks for all the info! ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Server with 4 drives, how to configure ZFS?
- Исходное сообщение - От: Dave U. Random anonym...@anonymitaet-im-inter.net Дата: Tuesday, June 21, 2011 18:32 Тема: Re: [zfs-discuss] Server with 4 drives, how to configure ZFS? Кому (To): zfs-discuss@opensolaris.org Hello Jim! I understood ZFS doesn't like slices but from your reply maybe I should reconsider. I have a few older servers with 4 bays x 73G. If I make a root mirror pool and swap on the other 2 as you suggest, then I would have about 63G x 4 left over. For the sake of completeness, I should mention that you can also create a fast and redundant 4-way mirrored root pool ;) If so then I am back to wondering what to do about 4 drives. Is raidz1 worthwhile in this scenario? That is less redundancythat a mirror and much less than a 3 way mirror, isn't it? Is it even possible to do raidz2 on 4 slices? Or would 2, 2 way mirrors be better? I don't understand what RAID10 is, is it simply a stripe of two mirrors? Yes, by that I meant a striping over two mirrors. Or would it be best to do a 3 way mirror and a hot spare? I would like to be able to tolerate losing one drive without loss of integrity. Any of the scenarios above allow you to lose one drive and not lose data immediately. The rest is a compromise between both performance, space and further redundancy: * 3- or 4-way mirror: least useable space (25% of total disk capacity), most redundancy, highest read speeds for concurrent loads * striping of mirrors (raid10): average useable space (50%), high read speeds for concurrent loads, can tolerate loss of up to 2 drives (slices) in a good scenario (if they are from different mirrors) * raidz2: average useable space (50%), can tolerate loss of any 2 drives * raidz1: max useable space (75%), can tolerate loss of any 1 drive After all the discussions about performance recently on this forum, I would not try to guess which performance would be better in general - raidz1 or raidz2 (there are reads, writes, scrubs and resilvers seemingly all with different preferences toward disk layout), but with a generic workload we have (i.e. serving up zones with some development databases and J2SE app servers) this was not seen to matter much. So for us it was usually raidz2 for tolerance or raidz1 for space. I will be doing new installs of Solaris 10. Is there an option in the installer for me to issue ZFS commands and set up pools or do I need to format the disks before installing and if so how do I do that? Unfortunately, I last installed Solaris 10u7 or so from scratch, others were liveupdates of existing systems and OpenSolaris machines, so I am not certain. From what I gather, the text installer is much more powerful than the graphical one, and its ZFS root setup might encompass creating a root pool in a slice of given size, and possibly mirror it right away. Maybe you can do likewise in JumpStart, but we did not do that after all. Anyhow, after you install a ZFS root of your sufficient size (i.e. our minimalist Solaris 10 installs are often under 1-2Gb per boot environment, multiply for storing different OEs like LiveUpdate and for snapshot history), you can create a slice for the data pool component (s3 in our setups), and then clone the disk slice layout to the other 3 drives like this: # prtvtoc /dev/rdsk/c1t0d0s2 | fmthard -s - /dev/rdsk/c1t1d0s2 (you might need to install the slice table spanning 100% of drives with the fdisk command, first). Then you attach one of the slices to the ZFS root pool to make a mirror, if the installer did not do that: # zpool attach rpool c1t0d0s0 c1t1d0s0 If you have several controllers (perhaps even on different PCI buses) you might want to pick a drive on a different controller than the first one in order to have less SPoF's, but make sure that the second controller is bootable from BIOS. And make that drive bootable: SPARC: # installboot /usr/platform/`uname -i`/lib/fs/ufs/bootblk /dev/rdsk/c1t1d0s0 x86/x86_64: # installgrub /boot/grub/stage1 /boot/grub/stage2 /dev/rdsk/c1t1d0s0 For two other drives you just create a new pool in slices *s0: # zpool create swappool mirror c1t2d0s0 c1t3d0s0 # zfs create -V2g swappool/dump # zfs create -V6g swappool/swap Sizes are arbitrary here, they depend on your RAM sizing. You can later add swap from other pools, including a data pool. Dump device size can be tested by configuring dumpadm to use the new device - it would either refuse to use a device too small (then you recreate it bigger), or accept it. The installer would probably create a dump and a swap devices in your root pool, you may elect to destroy them since you have another swap device, at least. Make sure to update the /etc/vfstab file to reference the swap areas which your system should use further on. After this is all completed, you can create a data pool in the s3 slices with your chosen geometry, i.e. # zpool create pool raidz2 c1t0d0s3 c1t1d0s3 c1t2d0s3 c1t3d0s3 In our setups
Re: [zfs-discuss] Server with 4 drives, how to configure ZFS?
In this setup that will install everything on the root mirror so I will have to move things around later? Like /var and /usr or whatever I don't want on the root mirror? Actually, you do want /usr and much of /var on the root pool, they are integral parts of the svc:/filesystem/local needed to bring up your system to a useable state (regardless of whether the other pools are working or not). Depending on the OS versions, you can do manual data migrations to separate datasets of the root pool, in order to keep some data common between OE's or to enforce different quotas or compression rules. For example, on SXCE and Solaris 10 (but not on oi_148a) we successfully splice out many filesystems in such a layout (the example below also illustrates multiple OEs): # zfs list -o name,refer,quota,compressratio,canmount,mountpoint -t filesystem -r rpool NAMEREFER QUOTA RATIO CANMOUNT MOUNTPOINT rpool 7.92M none 1.45xon /rpool rpool/ROOT 21K none 1.38xnoauto /rpool/ROOT rpool/ROOT/snv_117 758M none 1.00xnoauto / rpool/ROOT/snv_117/opt 27.1M none 1.00xnoauto /opt rpool/ROOT/snv_117/usr 416M none 1.00xnoauto /usr rpool/ROOT/snv_117/var 122M none 1.00xnoauto /var rpool/ROOT/snv_129 930M none 1.45xnoauto / rpool/ROOT/snv_129/opt 109M none 2.70xnoauto /opt rpool/ROOT/snv_129/usr 509M none 2.71xnoauto /usr rpool/ROOT/snv_129/var 288M none 2.54xnoauto /var rpool/SHARED 18K none 3.36xnoauto legacy rpool/SHARED/var 18K none 3.36xnoauto legacy rpool/SHARED/var/adm 2.97M 5G 4.43xnoauto legacy rpool/SHARED/var/cores 118M 5G 3.44xnoauto legacy rpool/SHARED/var/crash 1.39G 5G 3.41xnoauto legacy rpool/SHARED/var/log102M 5G 3.43xnoauto legacy rpool/SHARED/var/mail 66.4M none 1.79xnoauto legacy rpool/SHARED/var/tmp 20K none 1.00xnoauto legacy rpool/test 50.5K none 1.00xnoauto /rpool/test Mounts of /var/* components are done via /etc/vfstab lines like: rpool/SHARED/var/adm- /var/admzfs - yes - rpool/SHARED/var/log- /var/logzfs - yes - rpool/SHARED/var/mail - /var/mail zfs - yes - rpool/SHARED/var/crash - /var/crash zfs - yes - rpool/SHARED/var/cores - /var/cores zfs - yes - While system paths /usr /var /opt are mounted by SMF services directly. And then I just make a RAID10 like Jim was saying with the other 4x60 slices? How should I move mountpoints that aren't separate ZFS filesystems? The only conclusion you can draw from that is: First take it as a given that you can't boot from a raidz volume. Given, you must have one mirror. Thanks, I will keep it in mind. Then you raidz all the remaining space that's capable of being put into a raidz... And what you have left is a pair of unused space, equal to the size of your boot volume. You either waste that space, or you mirror it and put it into your tank. ...or use it as swap space :) I didn't understand what you suggested about appending a 13G mirror to tank. Would that be something like RAID10 without actually being RAID10 so I could still boot from it? How would the system use it? No, this would be an uneven striping over a raid10 (or raidzN) bank of 60Gb slices and a 13Gb mirror. ZFS can do that too, although for performance considerations unbalanced pools are not recommended and should be forced on command-line. And you can not boot from any pool other than a mirror or a single drive. Rationale: a single BIOS device must be sufficient to boot the system and contain all the data needed to boot. So RAID10 sounds like the only reasonable choice since there are an even number of slices, I mean is RAIDZ1 even possible with 4 slices? Yes, it is possible with any amount of slices starting from 3. ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss -- ++ || | Климов Евгений, Jim Klimov | | технический директор CTO | | ЗАО ЦОС и ВТ JSC COSHT | || | +7-903-7705859 (cellular) mailto:jimkli...@cos.ru | |CC:ad...@cos.ru,jimkli...@gmail.com | ++ | () ascii ribbon
Re: [zfs-discuss] Server with 4 drives, how to configure ZFS?
Hello Bob! Thanks for the reply. I was thinking about going with a 3 way mirror and a hot spare. Keep in mind that you can have problems in Sol10u8 if you use a mirror+spare config for the root pool. Should be fixed in u9. But I don't think I can upgrade to larger drives unless I do it all at once, is that correct? You can replace the drives one by one, but the pool will only expand when all the data drives have newer bigger capacity. //Jim ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Server with 4 drives, how to configure ZFS?
Edward Ned Harvey opensolarisisdeadlongliveopensola...@nedharvey.com wrote: Well ... Slice all 4 drives into 13G and 60G. Use a mirror of 13G for the rpool. Use 4x 60G in some way (raidz, or stripe of mirrors) for tank Use a mirror of 13G appended to tank Hi Edward! Thanks for your post. I think I understand what you are saying but I don't know how to actually do most of that. If I am going to make a new install of Solaris 10 does it give me the option to slice and dice my disks and to issue zpool commands? Until now I have only used Solaris on Intel with boxes and used both complete drives as a mirror. Can you please tell me what are the steps to do your suggestion? I imagine I can slice the drives in the installer and then setup a 4 way root mirror (stupid but as you say not much choice) on the 13G section. Or maybe one root mirror on two slices and then have 13G aux storage left to mirror for something like /var/spool? What would you recommend? I didn't understand what you suggested about appending a 13G mirror to tank. Would that be something like RAID10 without actually being RAID10 so I could still boot from it? How would the system use it? In this setup that will install everything on the root mirror so I will have to move things around later? Like /var and /usr or whatever I don't want on the root mirror? And then I just make a RAID10 like Jim was saying with the other 4x60 slices? How should I move mountpoints that aren't separate ZFS filesystems? The only conclusion you can draw from that is: First take it as a given that you can't boot from a raidz volume. Given, you must have one mirror. Thanks, I will keep it in mind. Then you raidz all the remaining space that's capable of being put into a raidz... And what you have left is a pair of unused space, equal to the size of your boot volume. You either waste that space, or you mirror it and put it into your tank. So RAID10 sounds like the only reasonable choice since there are an even number of slices, I mean is RAIDZ1 even possible with 4 slices? ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Server with 4 drives, how to configure ZFS?
Hello Bob! Thanks for the reply. I was thinking about going with a 3 way mirror and a hot spare. But I don't think I can upgrade to larger drives unless I do it all at once, is that correct? ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Server with 4 drives, how to configure ZFS?
On Thu, Jun 23, 2011 at 12:48 AM, Nomen Nescio nob...@dizum.com wrote:
Hello Bob! Thanks for the reply. I was thinking about going with a 3 way
mirror and a hot spare. But I don't think I can upgrade to larger drives
unless I do it all at once, is that correct?
Why keep one out as a Hot Spare ? If you have another zpool and
the Hot Spare will be shared, that makes sense. If the drive is
powered on and spinning, I don't see any downside to making it a 4-way
mirror instead of 3-way + HS.
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Re: [zfs-discuss] Server with 4 drives, how to configure ZFS?
Paul Kraus wrote: On Thu, Jun 23, 2011 at 12:48 AM, Nomen Nescio nob...@dizum.com wrote: Hello Bob! Thanks for the reply. I was thinking about going with a 3 way mirror and a hot spare. But I don't think I can upgrade to larger drives unless I do it all at once, is that correct? Why keep one out as a Hot Spare ? If you have another zpool and the Hot Spare will be shared, that makes sense. If the drive is powered on and spinning, I don't see any downside to making it a 4-way mirror instead of 3-way + HS. -- Also, to add larger disks to a mirrored pool, you can replace the mirror members, one at a time, with the larger disk and wait for resilver to complete. Then replace the other disk, resilver again. Craig -- Craig Cory Senior Instructor :: ExitCertified : Oracle/Sun Certified System Administrator : Oracle/Sun Certified Network Administrator : Oracle/Sun Certified Security Administrator : Symantec/Veritas Certified Instructor : RedHat Certified Systems Administrator +-+ ExitCertified :: Excellence in IT Certified Education Certified training with Oracle, Sun Microsystems, Apple, Symantec, IBM, Red Hat, MySQL, Hitachi Storage, SpringSource and VMWare. 1.800.803.EXIT (3948) | www.ExitCertified.com +-+ ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Server with 4 drives, how to configure ZFS?
Hi Dave, Consider the easiest configuration first and it will probably save you time and money in the long run, like this: 73g x 73g mirror (one large s0 on each disk) - rpool 73g x 73g mirror (use whole disks) - data pool Then, get yourself two replacement disks, a good backup strategy, and we all sleep better. Convert the complexity of some of the suggestions to time and money for replacement if something bad happens, and the formula would look like this: time to configure x time to replace x replacement disks = $$ cost of two replacement for two mirrored pools A complex configuration of slices and a combination of raidZ and mirrored pools across the same disks will be difficult to administer, performance will be unknown, not to mention how much time it might take to replace a disk. Use the simplicity of ZFS as it was intended is my advice and you will save time and money in the long run. Cindy On 06/23/11 07:38, Dave U. Random wrote: Edward Ned Harvey opensolarisisdeadlongliveopensola...@nedharvey.com wrote: Well ... Slice all 4 drives into 13G and 60G. Use a mirror of 13G for the rpool. Use 4x 60G in some way (raidz, or stripe of mirrors) for tank Use a mirror of 13G appended to tank Hi Edward! Thanks for your post. I think I understand what you are saying but I don't know how to actually do most of that. If I am going to make a new install of Solaris 10 does it give me the option to slice and dice my disks and to issue zpool commands? Until now I have only used Solaris on Intel with boxes and used both complete drives as a mirror. Can you please tell me what are the steps to do your suggestion? I imagine I can slice the drives in the installer and then setup a 4 way root mirror (stupid but as you say not much choice) on the 13G section. Or maybe one root mirror on two slices and then have 13G aux storage left to mirror for something like /var/spool? What would you recommend? I didn't understand what you suggested about appending a 13G mirror to tank. Would that be something like RAID10 without actually being RAID10 so I could still boot from it? How would the system use it? In this setup that will install everything on the root mirror so I will have to move things around later? Like /var and /usr or whatever I don't want on the root mirror? And then I just make a RAID10 like Jim was saying with the other 4x60 slices? How should I move mountpoints that aren't separate ZFS filesystems? The only conclusion you can draw from that is: First take it as a given that you can't boot from a raidz volume. Given, you must have one mirror. Thanks, I will keep it in mind. Then you raidz all the remaining space that's capable of being put into a raidz... And what you have left is a pair of unused space, equal to the size of your boot volume. You either waste that space, or you mirror it and put it into your tank. So RAID10 sounds like the only reasonable choice since there are an even number of slices, I mean is RAIDZ1 even possible with 4 slices? ___ 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] Server with 4 drives, how to configure ZFS?
Hi Dave, Hi Cindy. Consider the easiest configuration first and it will probably save you time and money in the long run, like this: 73g x 73g mirror (one large s0 on each disk) - rpool 73g x 73g mirror (use whole disks) - data pool Then, get yourself two replacement disks, a good backup strategy, and we all sleep better. Oh, you're throwing in free replacement disks too?! This is great! :P A complex configuration of slices and a combination of raidZ and mirrored pools across the same disks will be difficult to administer, performance will be unknown, not to mention how much time it might take to replace a disk. Yeah that's a very good point. But if you guys will make ZFS filesystems span vdevs then this could work even better! You're right about the complexity but OTOH the great thing about ZFS is not having to worry about how to plan mount point allocations and with this scenario (I also have a few servers with 4x36) the planning issue raises its ugly head again. That's why I kind of like Edward's suggestion even though it is complicated (for me) still I think it may be best given my goals. I like breathing room and not having to worry about a filesystem filling, it's great not having to know exactly ahead of time how much I have to allocate for a filesystem and instead let the whole drive be used as needed. Use the simplicity of ZFS as it was intended is my advice and you will save time and money in the long run. Thanks. I guess the answer is really using the small drives for root pools and then getting the biggest drives I can afford for the other bays. Thanks to everybody. ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Server with 4 drives, how to configure ZFS?
From: zfs-discuss-boun...@opensolaris.org [mailto:zfs-discuss- boun...@opensolaris.org] On Behalf Of Nomen Nescio Hello Bob! Thanks for the reply. I was thinking about going with a 3 way mirror and a hot spare. But I don't think I can upgrade to larger drives unless I do it all at once, is that correct? No point in doing 3-way mirror and hotspare. Just do 4-way mirror. ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Server with 4 drives, how to configure ZFS?
From: zfs-discuss-boun...@opensolaris.org [mailto:zfs-discuss- boun...@opensolaris.org] On Behalf Of Dave U.Random If I am going to make a new install of Solaris 10 does it give me the option to slice and dice my disks and to issue zpool commands? No way that I know of, to install Solaris 10 into partitions. Solaris 11 does it. On solaris 10, if you want to do this, you have to do a bunch of extra hassle. ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Server with 4 drives, how to configure ZFS?
Hello! I don't see the problem. Install the OS onto a mirrored partition, and configure all the remaining storage however you like - raid or mirror or watever. I didn't understand your point of view until I read the next paragraph. My personal preference, assuming 4 disks, since the OS is mostly reads and only a little bit of writes, is to create a 4-way mirrored 100G partition for the OS, and the remaining 900G of each disk (or whatever) becomes either a stripe of mirrors or raidz, as appropriate in your case, for the storagepool. Oh, you are talking about 1T drives and my servers are all 4x73G! So it's a fairly big deal since I have little storage to waste and still want to be able to survive losing one drive. I should have given the numbers at the beginning, sorry. Given this meager storage do you have any suggestions? Thank you. ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Server with 4 drives, how to configure ZFS?
From: zfs-discuss-boun...@opensolaris.org [mailto:zfs-discuss- boun...@opensolaris.org] On Behalf Of Dave U.Random My personal preference, assuming 4 disks, since the OS is mostly reads and only a little bit of writes, is to create a 4-way mirrored 100G partition for the OS, and the remaining 900G of each disk (or whatever) becomes either a stripe of mirrors or raidz, as appropriate in your case, for the storagepool. Oh, you are talking about 1T drives and my servers are all 4x73G! So it's a fairly big deal since I have little storage to waste and still want to be able to survive losing one drive. Well ... Slice all 4 drives into 13G and 60G. Use a mirror of 13G for the rpool. Use 4x 60G in some way (raidz, or stripe of mirrors) for tank Use a mirror of 13G appended to tank That would use all your space as efficiently as possible, while providing at least one level of redundancy, and the only sacrifice you're making is the fact that you get different performance characteristics between a raidz and a mirror, which are both in the same pool. For example, you might decide the ideal performance characteristics for your workload are to use raidz... Or to use mirrors ... but your pool is a hybrid, so you can't achieve the ideal performance characteristics no matter which type of data workload you have. That is a very small sacrifice, considering the constraints you're up against for initial conditions. I have 4x 73G disks I want to survive a single disk failure I don't want to waste any space and My boot pool must be included. The only conclusion you can draw from that is: First take it as a given that you can't boot from a raidz volume. Given, you must have one mirror. Then you raidz all the remaining space that's capable of being put into a raidz... And what you have left is a pair of unused space, equal to the size of your boot volume. You either waste that space, or you mirror it and put it into your tank. It's really the only solution, without changing your hardware or design constraints. ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Server with 4 drives, how to configure ZFS?
Hello Jim! I understood ZFS doesn't like slices but from your reply maybe I should reconsider. I have a few older servers with 4 bays x 73G. If I make a root mirror pool and swap on the other 2 as you suggest, then I would have about 63G x 4 left over. If so then I am back to wondering what to do about 4 drives. Is raidz1 worthwhile in this scenario? That is less redundancy that a mirror and much less than a 3 way mirror, isn't it? Is it even possible to do raidz2 on 4 slices? Or would 2, 2 way mirrors be better? I don't understand what RAID10 is, is it simply a stripe of two mirrors? Or would it be best to do a 3 way mirror and a hot spare? I would like to be able to tolerate losing one drive without loss of integrity. I will be doing new installs of Solaris 10. Is there an option in the installer for me to issue ZFS commands and set up pools or do I need to format the disks before installing and if so how do I do that? Thank you. ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Server with 4 drives, how to configure ZFS?
Hello Marty! With four drives you could also make a RAIDZ3 set, allowing you to have the lowest usable space, poorest performance and worst resilver times possible. That's not funny. I was actually considering this :p But you have to admit, it would probably be somewhat reliable! ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Server with 4 drives, how to configure ZFS?
On 21 June, 2011 - Nomen Nescio sent me these 0,4K bytes:
Hello Marty!
With four drives you could also make a RAIDZ3 set, allowing you to have
the lowest usable space, poorest performance and worst resilver times
possible.
That's not funny. I was actually considering this :p
4-way mirror would be way more useful.
But you have to admit, it would probably be somewhat reliable!
/Tomas
--
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|- Student at Computing Science, University of Umeå
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Re: [zfs-discuss] Server with 4 drives, how to configure ZFS?
On Jun 15, 2011, at 1:33 PM, Nomen Nescio wrote: Has there been any change to the server hardware with respect to number of drives since ZFS has come out? Many of the servers around still have an even number of drives (2, 4) etc. and it seems far from optimal from a ZFS standpoint. All you can do is make one or two mirrors, or a 3 way mirror and a spare, right? Wouldn't it make sense to ship with an odd number of drives so you could at least RAIDZ? Or stop making provision for anything except 1 or two drives or no drives at all and require CD or netbooting and just expect everybody to be using NAS boxes? I am just a home server user, what do you guys who work on commercial accounts think? How are people using these servers? I see 2 disks for boot and usually one or more 24-disk JBODs. A few 12-disk JBODs are still being sold, but I rarely see a single 12-disk JBOD. I'm also seeing a few SBBs that have 16 disks and boot from SATA DOMs. Anyone else? -- richard ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Server with 4 drives, how to configure ZFS?
As recently discussed on this list, after all ZFS does not care very much for the number of drives in a raidzN set, so optimization is not about stripe alignment and stuff but about number of spindles, resilver times, number of redundancy disks, etc. In my setups with 4 identical drives in a server I typically made a 10-20Gb rpool as a mirror of slices on a couple of drives, a same-sized pool for swap on the other couple of drives, and this leaves me with 4 identical-sized slices for a separate data pool. Depending on requirements we can do any layout: performance (raid10) vs. reliable (raidz2) vs space (raidz1). HTH, //Jim 2011-06-16 0:33, Nomen Nescio пишет: Has there been any change to the server hardware with respect to number of drives since ZFS has come out? Many of the servers around still have an even number of drives (2, 4) etc. and it seems far from optimal from a ZFS standpoint. All you can do is make one or two mirrors, or a 3 way mirror and a spare, right? Wouldn't it make sense to ship with an odd number of drives so you could at least RAIDZ? Or stop making provision for anything except 1 or two drives or no drives at all and require CD or netbooting and just expect everybody to be using NAS boxes? I am just a home server user, what do you guys who work on commercial accounts think? How are people using these servers? ___ 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] Server with 4 drives, how to configure ZFS?
On Wed, 15 Jun 2011, Nomen Nescio wrote: Has there been any change to the server hardware with respect to number of drives since ZFS has come out? Many of the servers around still have an even number of drives (2, 4) etc. and it seems far from optimal from a ZFS standpoint. All you can do is make one or two mirrors, or a 3 way mirror and a spare, right? Wouldn't it make sense to ship with an odd number of drives so you could at least RAIDZ? Or stop making provision for anything except 1 Yes, it all seems pretty silly. Using a small dedicated boot drive (maybe an SSD or Compact Flash) would make sense so that the main disks can all be used in one pool. FreeBSD apparently supports booting from raidz so it would allow booting from a four-disk raidz pool. Unfortunately, Solaris does not support that. Given a fixed number of drive bays, there may be value to keeping one drive bay completely unused (hot/cold spare, or empty). The reason for this is that it allows you to insert new drives in order to upgrade the drives in your pool, or handle the case of a broken drive bay. Without the ability to insert a new drive, you need to compromise the safety of your pool in order to replace a drive or upgrade the drives to a larger size. 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] Server with 4 drives, how to configure ZFS?
Has there been any change to the server hardware with respect to number of drives since ZFS has come out? Many of the servers around still have an even number of drives (2, 4) etc. and it seems far from optimal from a ZFS standpoint. All you can do is make one or two mirrors, or a 3 way mirror and a spare, right? With four drives you could also make a RAIDZ3 set, allowing you to have the lowest usable space, poorest performance and worst resilver times possible. Sorry, couldn't resist. -- 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] Server with 4 drives, how to configure ZFS?
On Wed, Jun 15, 2011 at 4:33 PM, Nomen Nescio nob...@dizum.com wrote: Has there been any change to the server hardware with respect to number of drives since ZFS has come out? Many of the servers around still have an even number of drives (2, 4) etc. and it seems far from optimal from a ZFS standpoint. With enterprise-level 2.5 drives hitting 1TB, I've decided to buy only 2.5-based chassis, which typically provide 6-8 bays in a 1U form factor. That's more than enough to build an rpool mirror and a raidz1+spare, raidz2, or 3x-mirror pool for data. Having 8 bays is also a nice fit for the typical 8-port SAS HBA. Eric ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Server with 4 drives, how to configure ZFS?
From: zfs-discuss-boun...@opensolaris.org [mailto:zfs-discuss- boun...@opensolaris.org] On Behalf Of Nomen Nescio Has there been any change to the server hardware with respect to number of drives since ZFS has come out? Many of the servers around still have an even number of drives (2, 4) etc. and it seems far from optimal from a ZFS standpoint. I don't see the problem. Install the OS onto a mirrored partition, and configure all the remaining storage however you like - raid or mirror or whatever. My personal preference, assuming 4 disks, since the OS is mostly reads and only a little bit of writes, is to create a 4-way mirrored 100G partition for the OS, and the remaining 900G of each disk (or whatever) becomes either a stripe of mirrors or raidz, as appropriate in your case, for the storagepool. ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
