[DRBD-user] Slow sync

James Pifer jep at obrien-pifer.com
Mon Jul 26 20:25:48 CEST 2010

Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.

I'm new to drbd and eventually want to use ocfs2 over drbd on sles11 in
a dual primary setup. Like many others I'm having slow sync issues. I've
done a lot googling and trying different settings, but about the best I
can manage is:
speed: 3,476 (2,892) K/sec

My test environment is using two highend desktops with SATA drives. They
each have a second gigabit nic, connected with a regular CAT6 cable, not
crossover. (although I got similar speed with crossover)

hdparm gives me(same range on both machines):
 # hdparm -t /dev/sda

 Timing buffered disk reads:  330 MB in  3.01 seconds = 109.49 MB/sec

My config file looks like:
resource data {
   protocol     C;
   disk {
      on-io-error       pass_on;
   startup {
#      become-primary-on both;
   syncer {
      rate      1150M;
      al-extents        3389;
   net {
#      allow-two-primaries;
#      after-sb-0pri discard-zero-changes;
#      after-sb-1pri discard-secondary;
#      after-sb-2pri disconnect;
#      sndbuf-size       512k;
#      max-buffers      20480;
#      max-epoch-size   16384;

   on xenhost2 {
      device    /dev/drbd1 ;
      meta-disk internal;
      disk      /dev/sda4;
   on xenhost1 {
      device    /dev/drbd1 ;
      meta-disk internal;
      disk      /dev/sda4;

Any suggestions?


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