[DRBD-user] Slow sync

[James Pifer]

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

/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;
      no-disk-barrier;
      no-disk-flushes;
   }
   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 ;
      address   10.1.1.32:7789;
      meta-disk internal;
      disk      /dev/sda4;
   }
   on xenhost1 {
      device    /dev/drbd1 ;
      address   10.1.1.31:7789;
      meta-disk internal;
      disk      /dev/sda4;
   }
}

Any suggestions?

Thanks,
James