Maurice Volaski
2008-Nov-11 00:42 UTC
[zfs-discuss] Poor read/write performance when using ZFS iSCSI target
I was wondering if you ever figured this out or if you''ve reported it. I''m testing a configuration using snv_99 and am seeing similar behavior.>I want to take advantage of the iSCSI target support in the latest >release (svn_91) of OpenSolaris, and I''m running into some >performance problems when reading/writing from/to my target. I''m >including as much detail as I can so bear with me here... > >I''ve built an x86 OpenSolaris server (Intel Xeon running NV_91) with >a zpool of 15 750GB SATA disks, of which I''ve created and exported a >ZFS Volume with the shareiscsi=on property set to generate an iSCSI >target. > >My problem is, when I connect to this target from any initiator >(tested with both Linux 2.6 and OpenSolaris NV_91 SPARC and x86), >the read/write speed is dreadful (~ 3 megabytes / second!). When I >test read/write performance locally with the backing pool, I have >excellent speeds. The same can be said when I use services such as >NFS and FTP to move files between other hosts on the network and the >volume I am exporting as a Target. When doing this I have achieved >the near-Gigabit speeds I expect, which has me thinking this isn''t a >network problem of some sort (I''ve already disabled the Neagle >algorithm if you''re wondering). It''s not until I add the iSCSI >target to the stack that the speeds go south, so I am concerned that >I may be missing something in configuration of the target. >-- Maurice Volaski, mvolaski at aecom.yu.edu Computing Support, Rose F. Kennedy Center Albert Einstein College of Medicine of Yeshiva University