Jim Dunham wrote: > Ahmed, > > >> The setup is not there anymore, however, I will share as much details >> as I have documented. Could you please post the commands you have used >> and any differences you think might be important. Did you ever test >> with 2008.11 ? instead of sxce ? >> > > Specific to the following: > > >>>> While we should be getting minimal performance hit (hopefully), we >>>> got >>>> a big performance hit, disk throughput was reduced to almost 10% of >>>> the normal rate. >>>> > > It looks like I need to test on OpenSoalris 2008.11, not Solaris > Express CE (b105), since this version does not have access to a > version of 'dd' with a oflag=<option> setting. > > # dd if=/dev/zero of=/dev/zvol/rdsk/gold/xxVolNamexx oflag=dsync > bs=256M count=10 > dd: bad argument: "oflag=dsync >
Congratulations! You've been bit by the gnu-compatibility feature! SXCE and OpenSolaris have more than one version of dd. The difference is that OpenSolaris sets your default PATH to use /usr/gnu/bin/dd, which has the oflag option, while SXCE sets your default PATH to use /usr/bin/dd. -- richard > Using a setting of 'oflag=dsync' will have performance implications. > > Also there is an issue with an I/O of size bs=256M. SNDR's internal > architecture has a I/O unit chunk size of one bit in 32KB". Therefore > when doing an I/O of 256MB, this results in the need to set 8192 bits, > 1024 bytes, or 1KB of data with 0xFF. Although testing with an /O > size of 256MB is interesting, typical I/O tests are more like the > following: > http://www.opensolaris.org/os/community/performance/filebench/quick_start/ > > - Jim > > _______________________________________________ > zfs-discuss mailing list > zfs-discuss@opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss > _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
