[DRBD-user] degraded write performace

Jon Nelson jnelson-drbd at jamponi.net
Wed Mar 28 23:33:32 CEST 2007

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


On Wed, 28 Mar 2007, Duane Cox wrote:

> Hello list:
> 
> Could someone please assist in finding my performance bottleneck... (~90
> MB/sec raw write to ~20 MB/sec connected drbd)
> Of course, I expected to see better write performance than what I obtained.
> 
> I have read a few archived posts by Lars, and followed his steps at:
> http://lists.linbit.com/pipermail/drbd-user/2006-August/005495.html
> http://www.gossamer-threads.com/lists/drbd/users/10689#10689
> 
> Both servers are Dell 2650 with identical hardware connected via 1G
> ethernet.
> drbd resource is a single (meaning one per server) SCSI 36G 15K U320
> (ST336754LC) drive

What kind of NIC? My recollection is that the 2650 has the 
TigonIII (Broadcom) NIC. Personally, I've more trouble with them than 
you can throw a stick at. If you can get 'em, use the Intel or (slightly 
less preferable) the RTL8169. I've had other, less pleasant experiences 
with other chipsets in gig-e at high load.

Are you REALLY REALLY sure that it's not network problems?

Have you tried something really simple like a basic TCP benchmark 
between the two machines?

--
Jon Nelson <jnelson-drbd at jamponi.net>



More information about the drbd-user mailing list