[zfs-discuss] All drives intact but vdev UNAVAIL in raidz1
Hi all, I'm running FreeNAS 7 (based on FreeBSD 7.2) and using ZFS v.13. I had two 2TB drives and one 1TB drive in a raidz1. I recently bought another 2TB drive to replace the 1TB drive. Unfortunately, I ran into some serious issues which are described in the steps that I did below: First, I scrubbed the disks and found no errors. Next I turned off the computer, unplugged the 1TB drive and plugged in the new 2TB drive into the same SATA port. I turned on the machine, and executed 'zpool status'. The system hung and ignored all interrupt and kill signals, and terminated any shutdown sequence, so I hard-shutdown the machine. Next I unplugged the new 2TB drive and plugged in the old 1TB drive. When I enter 'zpool status' I see that the pool is UNAVAIL and the vdev is CORRUPTED, and all three drives are online. I tried to export import the pool, but was unable to import as there 'are not enough redundant copies of the data.' It seems quite likely that all of the data is intact, and that something different is preventing me from accessing the pool. What can I do to recover the pool? I have downloaded the Solaris 11 express livecd if that would be of any use. Thanks in advance, Tyler ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] All drives intact but vdev UNAVAIL in raidz1
On Tue, 6 Sep 2011, Tyler Benster wrote: It seems quite likely that all of the data is intact, and that something different is preventing me from accessing the pool. What can I do to recover the pool? I have downloaded the Solaris 11 express livecd if that would be of any use. Try running zdb -l on the disk and see if the labels are still there. Also, could you show us the output of 'zpools status'? Normally zfs would not hang if one disk of a raidz group is missing, but it might do that if one toplevel is missing. If the zdb command shows all four labels to be correct, then you can try a zpool scrub and see if that resilvers the data for you. ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] BAD WD drives - defective by design?
On Aug 29, 2011, at 2:07 PM, Roy Sigurd Karlsbakk wrote: Hi all It seems recent WD drives that aren't Raid edition can cause rather a lot of problems on RAID systems. We have a few machines with LSI controllers (6801/6081/9201) and we're seeing massive errors occuring. The usual pattern is a drive failing or even a resilver/scrub starting and then, suddenly, most drives on the whole backplane report errors. These are usually No Device (as reported by iostat -En), but the result is that we may see data corruption at the end. We also have a system setup with Hitachi Deskstars, which has been running for almost a year without issues. One system with a mixture of WD Blacks and greens showed the same errors as described, but has been working well after the WD drives were replaced by deskstars. Sounds familiar. Now, it seems WD has changed their firmware to inhibit people from using them for other things than toys (read: PCs etc). Since we've seen this issue on different controllers and different drives, and can't reproduce it with Hitachi Deskstars, I would guess the firmware upgrade from WD is the issue. Likely. Would it be possible to fix this in ZFS somehow? No, the error is 1-2 layers below ZFS. The drives seem to work well except for those No Device errors…. 'nuff said. -- richard ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] BAD WD drives - defective by design?
http://wdc.custhelp.com/app/answers/detail/a_id/1397/~/difference-between-desktop-edition-and-raid-%28enterprise%29-edition-drives ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
[zfs-discuss] zfs send and dedupe
Just curious if anyone has looked into the relationship between zpool dedupe, zfs zend dedupe, memory use, and network throughput. For example, does 'zfs send -D' use the same DDT as the pool? Or does it require more memory for it's own DDT, thus impacting performance of both? If you have a deduped pool on both ends of the send, does -D make any difference? If neither pool is deduped, does -D make a difference? We're waiting on a replacement backplane for our newest zfs-based storage box, so won't be able to look into this ourselves until next week at the earliest. Thought i'd check if anyone else has already done some comparisons or benchmarks. Cheers, Freddie fjwc...@gmail.com ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] zfs send and dedupe
On Sep 6, 2011, at 9:01 PM, Freddie Cash wrote: Just curious if anyone has looked into the relationship between zpool dedupe, zfs zend dedupe, memory use, and network throughput. Yes. For example, does 'zfs send -D' use the same DDT as the pool? No. Or does it require more memory for it's own DDT, thus impacting performance of both? Yes, no. If you have a deduped pool on both ends of the send, does -D make any difference? Yes, if the data is deduplicable. If neither pool is deduped, does -D make a difference? Yes, if the data is deduplicable. We're waiting on a replacement backplane for our newest zfs-based storage box, so won't be able to look into this ourselves until next week at the earliest. Thought i'd check if anyone else has already done some comparisons or benchmarks. I'm not aware of any benchmarks, and I'd be surprised if they could be applied to real-world cases. zfs send deduplication is very, very, very dependent on the data being sent. It is also dependent on the release, since it is broken in many OpenSolaris and derived builds. Fixes have recently been submitted into the illumos source tree. Recent Nexenta distributions also have the fixes. -- richard ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] zfs send and dedupe
On Tue, Sep 06, 2011 at 10:05:54PM -0700, Richard Elling wrote: On Sep 6, 2011, at 9:01 PM, Freddie Cash wrote: For example, does 'zfs send -D' use the same DDT as the pool? No. My understanding was that 'zfs send -D' would use the pool's DDT in building its own, if present. If blocks were known by the filesystem to be duplicate, it would use that knowledge to skip some work seeding its own ddt and stream back-references. This doesn't change the stream contents vs what it would have generated without these hints, so No still works as a short answer :) That understanding was based on discussions and blog posts at the time, not looking at code. At least in theory, it should help avoid reading and checksumming extra data blocks if this knowledge can be used, so less work regardless of measurable impact on send throughput. (It's more about diminished impact to other concurrent activities) The point has mostly been moot in practice, though, because I've found zfs send -D just plain doesn't work and often generates invalid streams, as you note. Good to know there are fixes. -- Dan. pgpjZ1t9mVCs0.pgp Description: PGP signature ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
