Yes I noticed that thread a while back and have been doing a great deal of testing with various scsi_vhci options. I am disappointed that the thread hasn't moved further since I also suspect that it is related to mpt-sas or multipath or expander related.
I was able to get aggregate writes up to 500MB out to the disks but reads have not improved beyond an aggregate average of about 50-70MBps for the pool. I did not look much at read speeds during alot of my previous testing because I thought write speeds were my issue... And I've since realized that my userland write speed problem from zpool <-> zpool was actually read limited. Since then I've tried mirrors, stripes, raidz, checked my drive caches, tested recordsizes, volblocksizes, clustersizes, combinations therein, tried vol-backed luns, file-backed luns, wcd=false - etc. Reads from disk are slow no matter what. Of course - once the arc cache is populated, the userland experience is blazing - because the disks are not being read. Seeing write speeds so much faster that read strikes me as quite strange from a hardware perspective, though, since writes also invoke a read operation - do they not? > This sounds very similar to another post last month. > http://opensolaris.org/jive/thread.jspa?messageID=4874 > 53 > > The trouble appears to be below ZFS, so you might try > asking on the > storage-discuss forum. > -- richard > On Jul 28, 2010, at 5:23 PM, Karol wrote: > > > I appear to be getting between 2-9MB/s reads from > individual disks in my zpool as shown in iostat -v > > I expect upwards of 100MBps per disk, or at least > aggregate performance on par with the number of disks > that I have. > > > > My configuration is as follows: > > Two Quad-core 5520 processors > > 48GB ECC/REG ram > > 2x LSI 9200-8e SAS HBAs (2008 chipset) > > Supermicro 846e2 enclosure with LSI sasx36 expander > backplane > > 20 seagate constellation 2TB SAS harddrives > > 2x 8GB Qlogic dual-port FC adapters in target mode > > 4x Intel X25-E 32GB SSDs available (attached via > LSI sata-sas interposer) > > mpt_sas driver > > multipath enabled, all four LSI ports connected for > 4 paths available: > > f_sym, load-balance logical-block region size 11 on > seagate drives > > f_asym_sun, load-balance none, on intel ssd drives > > > > currently not using the SSDs in the pools since it > seems I have a deeper issue here. > > Pool configuration is four 2-drive mirror vdevs in > one pool, and the same in another pool. 2 drives are > for OS and 2 drives aren't being used at the moment. > > > > Where should I go from here to figure out what's > wrong? > > Thank you in advance - I've spent days reading and > testing but I'm not getting anywhere. > > > > P.S: I need the aid of some Genius here. > > -- > > This message posted from opensolaris.org > > _______________________________________________ > > zfs-discuss mailing list > > zfs-discuss@opensolaris.org > > > http://mail.opensolaris.org/mailman/listinfo/zfs-discu > ss > > -- > Richard Elling > rich...@nexenta.com +1-760-896-4422 > Enterprise class storage for everyone > www.nexenta.com > > > > _______________________________________________ > zfs-discuss mailing list > zfs-discuss@opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discu > ss > -- This message posted from opensolaris.org _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
