Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
On 10/29/2014 05:34 AM, aurelien panizza wrote:
> I've got two servers connected via a switch with a dedicated 1Gb NIC. We have a SSD raid 1 on both
> servers (software RAID on Redhat 6.5).
> Full sync between the primary and the secondary is from 3MB/s to 12MB/s
> iostat report 100%util on /dev/drbd0 on the secondary.
Check whether there's a block device with a low max_hw_sectors_kb value
in your device stack:
> ls -1 /sys/block/*/queue/max_hw_sectors_kb | xargs -i bash -c 'echo -n "{} " ; cat {}'
If you see small values for max_hw_sectors_kb in one of these, chances
are that just inefficient smalls blocks are transferred - you can
also find a discussion on this in the DRBD mailing list archive, just
search for max_hw_sectors_kb.
Regards,
Lutz Vieweg