On 10/24/2013 1:41 PM, Lists wrote:
Was wondering if anybody here could weigh in with real-life experience? Performance/scalability?
I've only used ZFS on Solaris and FreeBSD. some general observations...
1) you need a LOT of ram for decent performance on large zpools. 1GB ram above your basic system/application requirements per terabyte of zpool is not unreasonable.
2) don't go overboard with snapshots. a few 100 are probably OK, but 1000s (*) will really drag down the performance of operations that enumerate file systems.
3) NEVER let a zpool fill up above about 70% full, or the performance really goes downhill.
4) I prefer using striped mirrors (aka raid10) over raidz/z2, but my applications are primarily database.
(*) ran into a guy who had 100s of zfs 'file systems' (mount points), per user home directories, and was doing nightly snapshots going back several years, and his zfs commands were taking a long long time to do anything, and he couldn't figure out why. I think he had over 10,000 filesystems * snapshots.