On Wed, Dec 30, 2009 at 8:55 PM, Steffen Plotner <swplot...@amherst.edu> wrote: > Hello, > > I was doing performance testing, validating zvol performance in > particularly, and found that zvol write performance to be slow ~35-44MB/s at > 1MB blocksize writes. I then tested the underlying zfs file system with the > same test and got 121MB/s. Is there any way to fix this? I really would > like to have compatible performance between the zfs filesystem and the zfs > zvols. > > # first test is a file test at the root of the zpool vg_satabeast8_vol0 > dd if=/dev/zero of=/vg_satabeast8_vol0/testing bs=1M count=32768 > 32768+0 records in > 32768+0 records out > 34359738368 bytes (34 GB) copied, 285.037 s, 121 MB/s > > # create zvol > zfs create -V 100G -b 4k vg_satabeast8_vol0/lv_test > > # test zvol with 'dsk' device >> dd if=/dev/zero of=/dev/zvol/dsk/vg_satabeast8_vol0/lv_test bs=1M >> count=32768 > 32768+0 records in > 32768+0 records out > 34359738368 bytes (34 GB) copied, 981.219 s, 35.0 MB/s > > # test zvol with 'rdsk' device (results are better than 'dsk', however, not > as good as a regular file) > dd if=/dev/zero of=/dev/zvol/rdsk/vg_satabeast8_vol0/lv_test bs=1M > count=32768 > 32768+0 records in > 32768+0 records out > 34359738368 bytes (34 GB) copied, 766.247 s, 44.8 MB/s > > >>uname -a > SunOS zfs-debug-node 5.11 snv_130 i86pc i386 i86pc Solaris > > I believe this problem is affecting performance tests others are doing with > Comstar and exported zvol logical units. > > Steffen > _______________________________________________________________________________________________ > Steffen Plotner Amherst College Tel > (413) 542-2348 > Systems/Network Administrator/Programmer PO BOX 5000 Fax > (413) 542-2626 > Systems & Networking Amherst, MA 01002-5000 > swplot...@amherst.edu > > > _______________________________________________ > zfs-discuss mailing list > zfs-discuss@opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss > >
Why did you make the ZFS file system have 4k blocks? I'd let ZFS manage that for you, which by default I believe is 128K -- Brent Jones br...@servuhome.net _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
