[DRBD-user] DRBD - Slow Performance

[Dan Lavu]

Florian,

I've read that before and I've certainly played around with a lot of the
settings. However I'm still getting the same results. 

This the current parameters that I'm running;
###############################################
#
# please have a a look at the example configuration file in
# /usr/share/doc/drbd/drbd.conf
#
global { usage-count no; }
common { syncer { rate 20M; } }

resource r0 {
        protocol C;
        startup {
                wfc-timeout 0;
                degr-wfc-timeout 120;
        }
        disk {
                on-io-error detach;
        }
        net {
                cram-hmac-alg "sha1";
                shared-secret "XXXXXXX";
                max-buffers 8000;
                max-epoch-size 8000;
                unplug-watermark 24;
                sndbuf-size 0;
        }
        syncer { rate 10M; al-extents 3389; }
###############################################

Anything and everything I've tried, I cannot get DRBD to sync faster
than 2MB/s. I have tested my IO and the drives can read and write at
30MB/s and I can push and pull at 20MB/s to the secondary node. 

Any further input is appreciated, I've been banging my head against this
for a while. Again, thanks in advance. 

Thanks,

Dan Lavu


-----Original Message-----
From: drbd-user-bounces at lists.linbit.com
[mailto:drbd-user-bounces at lists.linbit.com] On Behalf Of Florian Haas
Sent: Monday, February 15, 2010 1:39 PM
To: drbd-user at lists.linbit.com
Subject: Re: [DRBD-user] DRBD - Slow Performance

On 02/15/2010 05:42 PM, Digimer wrote:
> Dan Lavu wrote:
>> ###############################################
>>
>> version: 8.3.2 (api:88/proto:86-90)
>>
>> GIT-hash: dd7985327f146f33b86d4bff5ca8c94234ce840e build by 
>> mockbuild at v20z-x86-64.home.local, 2009-08-29 14:07:55
>>
>>  0: cs:SyncSource ro:Primary/Secondary ds:UpToDate/Inconsistent C 
>> r----
>>
>>     ns:11050876 nr:0 dw:0 dr:11059127 al:0 bm:674 lo:1 pe:4 ua:253 
>> ap:0 ep:1 wo:b oos:2388363296
>>
>>         [>....................] sync'ed:  0.5% (2332384/2343176)M
>>
>>         finish: 362:48:56 speed: 1,824 (1,908) K/sec
>>
>> ###############################################
> 
> The sync operation is not designed to go at max speed, as the array is

> totally usable while not sync'ed.

What on earth makes you think the second half of that sentence is true?

Dan:
http://www.drbd.org/users-guide/s-throughput-tuning.html#s-tune-al-exten
ts

Hope this helps.
Florian