Re: [zfs-discuss] Speeding up resilver on x4500

2009-07-22 Thread Roch
Stuart Anderson writes: > > On Jun 21, 2009, at 10:21 PM, Nicholas Lee wrote: > > > > > > > On Mon, Jun 22, 2009 at 4:24 PM, Stuart Anderson > > > > wrote: > > > > However, it is a bit disconcerting to have to run with reduced data > > protection for an entire week. While I am certai

Re: [zfs-discuss] Speeding up resilver on x4500

2009-06-23 Thread Stuart Anderson
On Jun 23, 2009, at 11:50 AM, Richard Elling wrote: (2) is there some reasonable way to read in multiples of these blocks in a single IOP? Theoretically, if the blocks are in chronological creation order, they should be (relatively) sequential on the drive(s). Thus, ZFS should be able

Re: [zfs-discuss] Speeding up resilver on x4500

2009-06-23 Thread Toby Thain
On 23-Jun-09, at 1:58 PM, Erik Trimble wrote: Richard Elling wrote: Erik Trimble wrote: All this discussion hasn't answered one thing for me: exactly _how_ does ZFS do resilvering? Both in the case of mirrors, and of RAIDZ[2] ? I've seen some mention that it goes in cronological order

Re: [zfs-discuss] Speeding up resilver on x4500

2009-06-23 Thread Richard Elling
Erik Trimble wrote: Richard Elling wrote: Erik Trimble wrote: All this discussion hasn't answered one thing for me: exactly _how_ does ZFS do resilvering? Both in the case of mirrors, and of RAIDZ[2] ? I've seen some mention that it goes in cronological order (which to me, means that the

Re: [zfs-discuss] Speeding up resilver on x4500

2009-06-23 Thread Erik Trimble
Richard Elling wrote: Erik Trimble wrote: All this discussion hasn't answered one thing for me: exactly _how_ does ZFS do resilvering? Both in the case of mirrors, and of RAIDZ[2] ? I've seen some mention that it goes in cronological order (which to me, means that the metadata must be read

Re: [zfs-discuss] Speeding up resilver on x4500

2009-06-23 Thread Richard Elling
Erik Trimble wrote: All this discussion hasn't answered one thing for me: exactly _how_ does ZFS do resilvering? Both in the case of mirrors, and of RAIDZ[2] ? I've seen some mention that it goes in cronological order (which to me, means that the metadata must be read first) of file creatio

Re: [zfs-discuss] Speeding up resilver on x4500

2009-06-22 Thread Erik Trimble
All this discussion hasn't answered one thing for me: exactly _how_ does ZFS do resilvering? Both in the case of mirrors, and of RAIDZ[2] ? I've seen some mention that it goes in cronological order (which to me, means that the metadata must be read first) of file creation, and that only use

Re: [zfs-discuss] Speeding up resilver on x4500

2009-06-22 Thread Stuart Anderson
On Jun 21, 2009, at 10:21 PM, Nicholas Lee wrote: On Mon, Jun 22, 2009 at 4:24 PM, Stuart Anderson > wrote: However, it is a bit disconcerting to have to run with reduced data protection for an entire week. While I am certainly not going back to UFS, it seems like it should be at least theo

Re: [zfs-discuss] Speeding up resilver on x4500

2009-06-22 Thread Bill Sommerfeld
On Mon, 2009-06-22 at 06:06 -0700, Richard Elling wrote: > Nevertheless, in my lab testing, I was not able to create a random-enough > workload to not be write limited on the reconstructing drive. Anecdotal > evidence shows that some systems are limited by the random reads. Systems I've run which

Re: [zfs-discuss] Speeding up resilver on x4500

2009-06-22 Thread Richard Elling
Stuart Anderson wrote: On Jun 21, 2009, at 8:57 PM, Richard Elling wrote: Stuart Anderson wrote: It is currently taking ~1 week to resilver an x4500 running S10U6, recently patched with~170M small files on ~170 datasets after a disk failure/replacement, i.e., wow, that is impressive. There

Re: [zfs-discuss] Speeding up resilver on x4500

2009-06-22 Thread Erik Trimble
Nicholas Lee wrote: On Mon, Jun 22, 2009 at 4:24 PM, Stuart Anderson mailto:ander...@ligo.caltech.edu>> wrote: However, it is a bit disconcerting to have to run with reduced data protection for an entire week. While I am certainly not going back to UFS, it seems like it should b

Re: [zfs-discuss] Speeding up resilver on x4500

2009-06-21 Thread Nicholas Lee
On Mon, Jun 22, 2009 at 4:24 PM, Stuart Anderson wrote: > > However, it is a bit disconcerting to have to run with reduced data > protection for an entire week. While I am certainly not going back to > UFS, it seems like it should be at least theoretically possible to do this > several orders of m

Re: [zfs-discuss] Speeding up resilver on x4500

2009-06-21 Thread Stuart Anderson
On Jun 21, 2009, at 8:57 PM, Richard Elling wrote: Stuart Anderson wrote: It is currently taking ~1 week to resilver an x4500 running S10U6, recently patched with~170M small files on ~170 datasets after a disk failure/replacement, i.e., wow, that is impressive. There is zero chance of doing

Re: [zfs-discuss] Speeding up resilver on x4500

2009-06-21 Thread Richard Elling
Stuart Anderson wrote: It is currently taking ~1 week to resilver an x4500 running S10U6, recently patched with~170M small files on ~170 datasets after a disk failure/replacement, i.e., wow, that is impressive. There is zero chance of doing that with a manageable number of UFS file systems.

[zfs-discuss] Speeding up resilver on x4500

2009-06-21 Thread Stuart Anderson
It is currently taking ~1 week to resilver an x4500 running S10U6, recently patched with~170M small files on ~170 datasets after a disk failure/replacement, i.e., scrub: resilver in progress for 53h47m, 30.72% done, 121h19m to go Is there anything that can be tuned to improve this performance,