[DRBD-user] Sync rate is 300K/s!

Jon Nelson jnelson-drbd at jamponi.net
Fri Mar 23 15:49:31 CET 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 Fri, 23 Mar 2007, James Vanns wrote:

> Ah! Well, a limit of ~250K/s would be it then! Seriously though, why 
> so low in the age of 1 and 10GigE? I understand you wouldn't want to 
> be responsible for saturation the link but isn't 250K being a little 
> *too* conservative? I have a dedicated crossover cable for this 
> between two 1GigE nvidia NICs. They are quite capable of a pretty 
> quick speed. I'll actually specify the rate and 'drbdadm adjust' 
> appropriately!

I have a pair of machines that sync at 25-27 MB/s over gig-e, and the 
speed there is limited by two things:

1. the host CPU of one of the machines (Duron 750)
2. the speed of the rather old 5400 rpm ATA/100 drives.

I hope to do some more tests soon with some slightly nicer hardware, I 
expect to do better.  I should note that the BEST TCP benchmark I've got 
between the two existing machines is 35-40 MB/s so I don't think that 
drbd is that far off.

Jon Nelson <jnelson-drbd at jamponi.net>

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