[CentOS] DRBD very slow....

[Coert Waagmeester]

On Mon, 2009-07-27 at 08:30 +0200, Coert Waagmeester wrote:
> On Mon, 2009-07-27 at 10:18 +0400, Roman Savelyev wrote:
> > > Invest in a HW RAID card with NVRAM cache that will negate the need
> > > for barrier writes from the OS as the controller will issue them async
> > > from cache allowing I/O to continue flowing. This really is the safest
> > > method.
> > It's a better way. But socket oprions in DRBD up to 8.2 (Nagel alghoritm) 
> > can decrease performance in large amount of small syncronius writes. 
> > 
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> 
> Hello Roman,
> 
> I am running drbd 8.2.6 (the standard centos version)
> 
> How do I disable that nagle algorithm?

On google I found the following page:
http://www.nabble.com/Huge-latency-issue-with-8.2.6-td18947965.html

I have found in the drbdsetup (8) man page the sndbuf-size option, and I
will try setting this.

On the nabble page they talk about the TCP_NODELAY and TCP_QUICKACK
socket option. Does this have to do with Nagle algorithm?

Where do I set these socket options? Do I have to compile drbd with
them?

> 
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