Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
Hello. Software: Debian Lenny 2.6.26-2-amd64 ocfs2-tools 1.4.1-1 drbd8-2.6.26-2-amd64 2:8.3.7-1~bpo50+1+2.6.26-21lenny4 drbd8-source 2:8.3.7-1~bpo50+1 drbd8-utils 2:8.3.7-1~bpo50+1 Hardware: Dell server Adaptec 5405 RAID Controller (write cache enabled) 2x1TB 7200rpm HDD I make some test for disk random access time and it is horrible: # ./seeker /dev/drbd0 Seeker v2.0, 2007-01-15, http://www.linuxinsight.com/how_fast_is_your_disk.html Benchmarking /dev/drbd0 [858643MB], wait 30 seconds.............................. Results: 65 seeks/second, 15.26 ms random access time While linear speed is good. # hdparm -Tt /dev/drbd0 /dev/drbd0: Timing cached reads: 13928 MB in 2.00 seconds = 6972.83 MB/sec Timing buffered disk reads: 628 MB in 3.01 seconds = 208.82 MB/sec Whats wrong with seek time? How can I tune\fix it? Seeks on non DRBD partition is more good: Results: 129 seeks/second, 7.71 ms random access time My drbd conf: # cat /etc/drbd.d/global_common.conf global { usage-count yes; } common { protocol C; handlers { pri-on-incon-degr "/usr/lib/drbd/notify-pri-on-incon-degr.sh; /usr/lib/drbd/notify-emergency-reboot.sh; echo b > /proc/sysrq-trigger ; reboot -f"; pri-lost-after-sb "/usr/lib/drbd/notify-pri-lost-after-sb.sh; /usr/lib/drbd/notify-emergency-reboot.sh; echo b > /proc/sysrq-trigger ; reboot -f"; local-io-error "/usr/lib/drbd/notify-io-error.sh; /usr/lib/drbd/notify-emergency-shutdown.sh; echo o > /proc/sysrq-trigger ; halt -f"; outdate-peer "/usr/lib/heartbeat/drbd-peer-outdater -t 5"; } startup { wfc-timeout 60; degr-wfc-timeout 30; outdated-wfc-timeout 15; become-primary-on both; } disk { fencing resource-and-stonith; no-disk-flushes; no-md-flushes; } net { cram-hmac-alg sha1; shared-secret "password"; allow-two-primaries; ping-timeout 20; after-sb-0pri discard-zero-changes; after-sb-1pri discard-secondary; after-sb-2pri disconnect; } syncer { rate 100M; } } # cat /etc/drbd.d/drbd0.res resource drbd0 { on server1.domain.org { device /dev/drbd0; disk /dev/sda9; address 192.168.1.1:7789; meta-disk internal; } on server2.domain.org { device /dev/drbd0; disk /dev/sda9; address 192.168.1.2:7789; meta-disk internal; } } -- С уважением, Проскурин Кирилл