I'm building some new SAS servers on a Power8. And I'd like to get i right, for best performance. The Compute server, has a /saswork mountpoint, for temporary data. I have followed the tuning guide, and then they mention this: For SAS WORK area file systems which store only temporary data, consider turning off logging to improve performance. # mount -o log=NULL /mountpoint Does any of you, have any expirience with this? Does it make a huge difference in performance? Other sugestions? My SAS Compute server - so far (SAS not installed): OSlevel 7200-01-01-1642 7 cores - SMT 8 56 GB RAM Each filesystem, has it's own Volume Group, with seperate disk for JFS2LOG: Filesystem GB blocks Free %Used Iused %Iused Mounted on /dev/saslv 249.88 249.84 1% 4 1% /sas /dev/sasworklv 249.88 249.84 1% 4 1% /saswork /dev/sasutillv 199.88 199.84 1% 4 1% /sasutil /dev/sasdatalv 1497.50 1497.27 1% 4 1% /sasdata /dev/spdsdatalv 1048.25 1048.09 1% 4 1% /spdsdata mounted mounted over vfs date options --------------- --------------- ------ ------------ --------------- /dev/saslv /sas jfs2 Mar 03 08:33 rw,rbw,rbr,noatime,log=/dev/sas_loglv /dev/sasworklv /saswork jfs2 Mar 03 08:33 rw,rbw,rbr,noatime,log=/dev/saswork_loglv /dev/sasutillv /sasutil jfs2 Mar 03 08:33 rw,rbw,rbr,noatime,log=/dev/sasutil_loglv /dev/sasdatalv /sasdata jfs2 Mar 03 08:33 rw,rbw,rbr,noatime,log=/dev/sasdata_loglv /dev/spdsdatalv /spdsdata jfs2 Mar 03 08:33 rw,rbw,rbr,noatime,log=/dev/spdsdata_loglv SAS has it's own HBA's. These tuning settings are also implemented: ioo -p -o j2_dynamicBufferPreallocation=256 -o j2_maxPageReadAhead=2048 -o j2_minPageReadAhead=16 -o j2_nPagesPerWriteBehindCluster=64 vmo -o nokilluid=10 no -o tcp_nodelayack=1 chdev -l sys0 -a maxuproc=2048 lvmo -v rootvg -o pv_pbuf_count=2048 apply "lvmo -v %1 -o pv_pbuf_count=1024" $(lsvg | grep -v root) maxfree = 15176 minfree = 960 Thankyou in advance 🙂 Chears Harald
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