Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
a) use oflag=direct or dd will just test caching. b) You show a 183MB/s rate, which is pretty good. However, the target appears not to be the drbd volume, you don't say if the resource is connected or waiting for connection, and you don't describe the underlying hardware. c) How is /mnt/mysql/syncing_drbd related to opt/drbd-test.loop or /dev/drdb1? Dan (the top poster) -----Original Message----- From: drbd-user-bounces at lists.linbit.com [mailto:drbd-user-bounces at lists.linbit.com] On Behalf Of rahulcs Sent: Tuesday, September 11, 2012 4:43 PM To: drbd-user at lists.linbit.com Subject: [DRBD-user] slow write performance Hi, I am using DRBD for syncing files between two machines on a LAN. I have created a device on a file using dd if=/dev/zero of=/opt/drbd-test.loop bs=1M count=200 losetup /dev/loop1 /opt/drbd-test.loop. My drbd resource settings are as follows: root at obelix101:/tmp# drbdsetup 1 show disk { size 0s _is_default; # bytes on-io-error pass_on _is_default; fencing dont-care _is_default; max-bio-bvecs 0 _is_default; } net { timeout 60 _is_default; # 1/10 seconds max-epoch-size 8000; max-buffers 8000; unplug-watermark 16; connect-int 10 _is_default; # seconds ping-int 10 _is_default; # seconds sndbuf-size 0 _is_default; # bytes rcvbuf-size 0 _is_default; # bytes ko-count 0 _is_default; after-sb-0pri disconnect _is_default; after-sb-1pri disconnect _is_default; after-sb-2pri disconnect _is_default; rr-conflict disconnect _is_default; ping-timeout 5 _is_default; # 1/10 seconds on-congestion block _is_default; congestion-fill 0s _is_default; # byte congestion-extents 127 _is_default; } syncer { rate 1024000k; # bytes/second after -1 _is_default; al-extents 3389; on-no-data-accessible io-error _is_default; c-plan-ahead 0 _is_default; # 1/10 seconds c-delay-target 10 _is_default; # 1/10 seconds c-fill-target 0s _is_default; # bytes c-max-rate 102400k _is_default; # bytes/second c-min-rate 4096k _is_default; # bytes/second } protocol C; _this_host { device minor 1; disk "/dev/loop1"; meta-disk internal; address ipv4 192.168.245.101:7789; } _remote_host { address ipv4 192.168.245.102:7789; } I am getting really bad write performance: root at obelix101:/tmp# time dd if=/dev/zero of=/mnt/mysql/syncing_drbd bs=1M count=12 12+0 records in 12+0 records out 12582912 bytes (13 MB) copied, 0.0686793 s, 183 MB/s real 3m49.773s user 0m0.000s sys 0m0.168s What am i doing wrong ? Thanking you, Rahul -- View this message in context: http://old.nabble.com/slow-write-performance-tp34419641p34419641.html Sent from the DRBD - User mailing list archive at Nabble.com. _______________________________________________ drbd-user mailing list drbd-user at lists.linbit.com http://lists.linbit.com/mailman/listinfo/drbd-user