zfs amd64 4gb raidz1 50% slower than bare drive, then locks.
Posted: 23 Jan 2013 21:23
A fresh install onto a usb memory stick, then a file move just crashes zfs on this system-- even though scrubs (though veeerrrry slooow ~ 12-18Mb/s) report no errors, smartd reports no errors. Exporting the pool and using 'disk info' on the zfs drives reports individual disk speeds in the expected 68Mbytes/s to 147Mb/s range for the spindles and 175Mb/s for the ssd.
I'm doing a move of some video files from one zfs dataset to another on the same raidz1 zpool. Zero other activity on the system. The files vary in size but generally 10G each. The commands are all given locally on the console, no networking. Simple unix 'mv'. The target dataset has no dedup, no compression. The source pool has checksums and compression. Basically, the zfs parts system just stops within a couple of minutes. Zero write traffic, all commands referencing zfs simply hang. 'ls -l <dataset>' never returns. Processors 99.7% idle. Swap space 0% used. Mem: 17M Active, 22M Inact, 1881M Wired, 12M Buf, 1531M Free
The original pool had 4 Hitachi 7200rpm 'deskstar' 1.5 TB drives in a raidz1, and 2 SSD's offering a bit of cache and zil. They were made on a Freebsd install then imported into Nas4Free. Same version of ZFS on all pools. I eliminated the cache and the zil from the pool: same issue. Tried the evil tuning guide, the zfs kernel tune extension, no meaninful change.
Even just doing reads with dd from a video file to /dev/null, although they complete, the performance is 80% of than the worst case speed of a single spindle drive, and less than half of a single drive's best case speed.
plenty of details at http://www.quietfountain.com/fs1pool1.txt .
The only hunch I have is that the fact writes are being completed somehow never make it back to ZFS?
The system is a Dell DImension 9150 (corrected error --not 6150). All the dmesg, statuses, and whatnot I could think of are in the link above.
Recap: I really expected this to be easy, I used a completely fresh install with zero changes of any sort. zpool import, zfs mount -a, mv <src 10gb file dataset1 > <dest dataset2> and then zfs hangs after a bit. Any further request to zfs hangs (eg ls -l <dataset2>). After a while, the only thing that works is switching among virtual ttys, while typing a character even at the login prompt does not echo. And, there it will sit until physically rebooted.
Help please!
I'm doing a move of some video files from one zfs dataset to another on the same raidz1 zpool. Zero other activity on the system. The files vary in size but generally 10G each. The commands are all given locally on the console, no networking. Simple unix 'mv'. The target dataset has no dedup, no compression. The source pool has checksums and compression. Basically, the zfs parts system just stops within a couple of minutes. Zero write traffic, all commands referencing zfs simply hang. 'ls -l <dataset>' never returns. Processors 99.7% idle. Swap space 0% used. Mem: 17M Active, 22M Inact, 1881M Wired, 12M Buf, 1531M Free
The original pool had 4 Hitachi 7200rpm 'deskstar' 1.5 TB drives in a raidz1, and 2 SSD's offering a bit of cache and zil. They were made on a Freebsd install then imported into Nas4Free. Same version of ZFS on all pools. I eliminated the cache and the zil from the pool: same issue. Tried the evil tuning guide, the zfs kernel tune extension, no meaninful change.
Even just doing reads with dd from a video file to /dev/null, although they complete, the performance is 80% of than the worst case speed of a single spindle drive, and less than half of a single drive's best case speed.
plenty of details at http://www.quietfountain.com/fs1pool1.txt .
The only hunch I have is that the fact writes are being completed somehow never make it back to ZFS?
The system is a Dell DImension 9150 (corrected error --not 6150). All the dmesg, statuses, and whatnot I could think of are in the link above.
Recap: I really expected this to be easy, I used a completely fresh install with zero changes of any sort. zpool import, zfs mount -a, mv <src 10gb file dataset1 > <dest dataset2> and then zfs hangs after a bit. Any further request to zfs hangs (eg ls -l <dataset2>). After a while, the only thing that works is switching among virtual ttys, while typing a character even at the login prompt does not echo. And, there it will sit until physically rebooted.
Help please!