I'm running Postgresql (v8.1.10) on Solaris 10 (Sparc) from within a non-global zone. I originally had the database "storage" in the non-global zone (e.g. /var/local/pgsql/data on a UFS filesystem) and was getting performance of "X" (e.g. from a TPC-like application: http://www.tpc.org). I then wanted to try relocating the database storage from the zone (UFS filesystem) over to a ZFS-based filesystem (where I could do things like set quotas, etc.). When I do this, I get roughly half the performance (X/2) I did on the UFS system.
I ran some low-level I/O tests (from http://iozone.org/) on my setup and have listed a sampling below for an 8k file and 8k record size: [Hopefully the table formatting survives] UFS filesystem [on local disk] ====================== Run KB reclen write rewrite read reread -------------------------------------------------------------------- 1 8 8 40632 156938 199960 222501 [./iozone -i 0 -i 1 -r 8 -s 8 -> no fsync include] 2 8 8 4517 5434 11997 11052 [./iozone -i 0 -i 1 -r 8 -s 8 -e -> fsync included] 3 8 8 4570 5578 199960 215360 [./iozone -i 0 -i 1 -r 8 -s 8 -o -> usig O_SYNC] ZFS filesystem [on StorageTek 2530 Array in RAID 1+0 configuration with a 512K segment size] ====================================================================== Run KB reclen write rewrite read reread -------------------------------------------------------------------------- 3 8 8 52281 95107 142902 142902 [./iozone -i 0 -i 1 -r 8 -s 8 -> no fsync include] 4 8 8 996 1013 129152 114206 [./iozone -i 0 -i 1 -r 8 -s 8 -e -> fsync included] 5 8 8 925 1007 145379 170495 [./iozone -i 0 -i 1 -r 8 -s 8 -o -> usig O_SYNC] Comparing run 1 and 3 shows that ZFS is roughly 20% faster on (unsynchronized) writes versus UFS. What's really surprising, to me at least, is that in cases 3 and 5, for example, ZFS becomes almost 400% slower on synchronized writes versus UFS. I realize that the ZFS-on-RAID setup has a "safety" penalty, but should it really be 400% slower than UFS? If not, then I'm hoping for suggestions on how to get some better ZFS performance from this setup. Thanks, Bob
_______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
