[DRBD-user] Doc update and Sync performance

Lars Ellenberg lars.ellenberg at linbit.com
Mon Jan 4 12:47:32 CET 2010

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, Dec 30, 2009 at 11:45:22AM -0700, Josh Aune wrote:
> 
> On Dec 30, 2009, at 3:27 AM, Lars Ellenberg wrote:
> 
> > On Tue, Dec 29, 2009 at 03:56:17PM -0700, Josh Aune wrote:
> >> Hi,
> >> 
> >> Attached is a patch for the users guide.
> > 
> > Thanks.
> > 
> >> Also, I'm having an issue with sync performance.  I have DRBD setup
> >> between two hosts using SRP.
> > 
> > SDP maybe?
> 
> Ya, that one :)
> 
> > 
> >> Under optimal conditions I'm able to achieve a 500+ MB/s write speed,
> > 
> > How do you measure?
> 
> $ iostat -m 1
> 
> On both hosts while running a benchmark.  On the host with the
> benchmark I see 500+ MB/s register on both the drbd1 and fioa devices,
> on the remote host it registers 500 MB/s on only the fioa device.
> 
> While running the initial sync both sides register between 50-80 MB/s
> reads, no writes.  Doing a local benchmark using 4 processes of 32k
> reads this device can easily sustain 600+ MB/s.
>
> >> but during the initial sync after the DRBD device is created the sync
> >> proceeds at less than 100 MB/s.  Below is the config file.  Am I
> >> missing anything needed to bump up the initial sync speed?
> >> 
> >> Also, all bytes on the drives on both side are zeros, so the limitation seems to be in the crc32c processing.
> > 
> > Did you look at top, vmstat or similar?
> 
> Yes, 87% cpu idle.  Nothing much really happening.

Then this seems to be some other config problem.

	<shameless plug>
Did you know we sell "DRBD Health Checks"?
http://www.linbit.com/en/products-services/drbd-consulting/
	</shameless plug>

 ;)

Cheers,


-- 
: Lars Ellenberg
: LINBIT | Your Way to High Availability
: DRBD/HA support and consulting http://www.linbit.com

DRBD® and LINBIT® are registered trademarks of LINBIT, Austria.
__
please don't Cc me, but send to list   --   I'm subscribed



More information about the drbd-user mailing list