[DRBD-user] resyncing, bandwidth limits and new writes.

atp Andrew.Phillips at lmax.com
Mon Apr 26 16:08:55 CEST 2010

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


 Thanks for the response. The io scheduler is already deadline. The
"HDD" is a hardware raid array of 12 drives, and shows no sign of
excessive iowait or read exhaustion. 

 I'm more interested in write bandwidth, not read, and how that competes
with the background replication bandwidth as a system is resyncing. 

 The problem appears to be that writes coming into the primary are
replicated across to the secondary, which is also resyncing. These can
take a long time to fulfil, and I'd like to give them priority. Secondly
does limiting the bandwidth for drbd apply just to resync writes, or to 
all drbd traffic.


On Mon, 2010-04-26 at 15:58 +0200, Luciano Rocha wrote:
> Your hdd bandwidth must be exhausted on reads. Try changing the IO scheduler to deadline.
Andrew Phillips
Head of Systems


Office: +44 203 1922509
Mobile: +44 (0)7595 242 900

LMAX | Level 2, Yellow Building | 1 Nicholas Road | London | W11 4AN

The information in this e-mail and any attachment is confidential and is intended only for the named recipient(s). The e-mail may not be disclosed or used by any person other than the addressee, nor may it be copied in any way. If you are not a named recipient please notify the sender immediately and delete any copies of this message. Any unauthorized copying, disclosure or distribution of the material in this e-mail is strictly forbidden. Any view or opinions presented are solely those of the author and do not necessarily represent those of the company.

More information about the drbd-user mailing list