Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
On 11-7-2011 16:23, Mark Dokter wrote: > I had the syncer rate at 30M before and set it to that high value out > of desperation. There's nothing much going on on the syncer network, > so this shouldn't be a problem. Depending on the protocol used (didn't see it in your config, I'm guessing C is default?) you'd want as low as a latency as possible. If protocol C, writes aren't "done" on primary if not confirmed by secondary. Roundtrip times then add up. > The two servers both have a dedicated nics which are connected to a > gbit switch. Some time ago, those two servers were right next to each > other (physically) and I tried a direct connection of those two nics, > which did not really make a difference, so I plugged them to the > switch again. Now those two servers are physically about 1km appart > in two different server facilities and connected via VLAN. That > shouldn't really matter, as bandwith and latency between those two > servers is quite acceptable (ping measures ~0.2 ms). My dedicated (bonded) links measure 0.007 ms. You could try another protocol, see if that helps. But my guess is that 'lots of small writes' makes one of the raid-disks bottleneck for activity log updates (which causes head-seeks, which causes slowness). Can you tune the HW-RAID to cache more? Try another physical device for the metadata, helped tremendously in my case (70 > 250 MB/s with dd). Is your filesystem (and is your LVM) aligned with the chunksize on the HW-RAID? Might cause a read/write/write otherwise, could be extra detrimental on raid-6. Lots of weasel words there, sorry! Mrten.