Richard Elling wrote: > 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!
Oh that's what one calls it... a 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. Thank you, Jim > > -- 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
