Guys, Have an opensolairs x86 box running:
SunOS thsudfile01 5.11 snv_111b i86pc i386 i86pc Solaris This has 2 old qla2200 1Gbit FC cards attached. Each bus is connected to an old transtec F/C raid array. This has a couple of large luns that form a single large zpool: r...@thsudfile01:~# zpool status bucket pool: bucket state: ONLINE scrub: none requested config: NAME STATE READ WRITE CKSUM bucket ONLINE 0 0 0 c5t0d0 ONLINE 0 0 0 c8t3d0 ONLINE 0 0 0 errors: No known data errors r...@thsudfile01:~# zfs list bucket NAME USED AVAIL REFER MOUNTPOINT bucket 2.69T 5.31T 22K /bucket This is being used as an iSCSI target for an ESX 4.0 development environemnt. I found the performance to be really poor and found the culprit seems to be write performance to the raw zvol. For example on this zfs filesystem allocated as a volume: r...@thsudfile01:~# zfs list bucket/iSCSI/lun1 NAME USED AVAIL REFER MOUNTPOINT bucket/iSCSI/lun1 250G 5.55T 3.64G - r...@thsudfile01:~# dd if=/dev/zero of=/dev/zvol/rdsk/bucket/iSCSI/lun1 bs=65536 count=102400 ^C7729+0 records in 7729+0 records out 506527744 bytes (507 MB) copied, 241.707 s, 2.1 MB/ Some zpool iostat 1 1000: bucket 2.44T 5.68T 0 203 0 2.73M bucket 2.44T 5.68T 0 216 0 2.83M bucket 2.44T 5.68T 0 120 63.4K 1.58M bucket 2.44T 5.68T 2 350 190K 16.9M bucket 2.44T 5.68T 0 123 0 1.64M bucket 2.44T 5.68T 0 230 0 3.02M Read performance from that zvol (assuming /dev/null behaves properly) is fine: r...@thsudfile01:/bucket/transtec# dd of=/dev/null if=/dev/zvol/rdsk/bucket/iSCSI/lun1 bs=65536 count=204800 204800+0 records in 204800+0 records out 13421772800 bytes (13 GB) copied, 47.0256 s, 285 MB/s Somewhat optimistic that... but iostat shows 100MB/s ish. Write to a zfs filesystem from that zpool is also fine, here with a a write big enough to exhaust the machines 12GB memory: r...@thsudfile01:/bucket/transtec# dd if=/dev/zero of=FILE bs=65536 count=409600 ^C 336645+0 records in 336645+0 records out 22062366720 bytes (22 GB) copied, 176.369 s, 125 MB/s and bursts of cache flush from iostat: bucket 2.44T 5.68T 0 342 0 38.7M bucket 2.44T 5.68T 0 1.47K 0 188M bucket 2.44T 5.68T 0 240 0 21.3M bucket 2.44T 5.68T 0 1.54K 0 191M bucket 2.44T 5.68T 0 1.49K 0 191M bucket 2.44T 5.68T 0 434 0 44.2M So we seem to be able to get data down to disk via the cache at a reasonable rate and read from a raw zvol OK, but writes are horribly slow. Am I missing something obvious? let me know what info would be diagnostic and I'll post it... Cheers, Leon -- This message posted from opensolaris.org _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss