Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
On Sat, Jan 28, 2012 at 02:01:50PM +0200, Samuli Heinonen wrote: > On 27.01.2012 15:35, Maurits van de Lande wrote: > >Hello, > > > >I have a couple of servers with SSD based raid arrays (capable of > >writing 550+MB/s to the disks). And a 10Gb/s network (HP NC552SFP > >network adapter HP E8206 network switches) > > > >Before installing the 10Gb network adapter the syncrate was > >limited to > >around 102MB/s (1Gb/s?) > > > >After Installing the 10Gb network adapter it was still impossible to > >get more than 102MB/s sync rate between the servers. > > > >I would like to have a 300MB/s sync rate. When I set this as a fixed > >sync rate in my drbd84 resource file I noticed that this value is > >ignored and 102MB/s is used. > > > >How can I increase the syncer rate in drbd84? > > Variable-rate synchronization is on by default in DRBD 8.4. I had to > set c-plan-head to 0 before I was able to change sync rate even > temporarily. More information can be found at > http://www.drbd.org/users-guide/s-recent-changes-defaults.html. You should not have disabled the dynamically adaptive resync rate controller, but instead adjusted it's parameters. c-max-rate (8.4 default 100 M; DRBD tries to go no faster than this), c-min-rate (8.4 default 250 k; DRBD may throttle resync in favor of application IO, if resync currently goes faster than this. No additional throttling if rate is already below this. disable resync throttling for application IO: 0) c-fill-target (should be about 1 to 2 times your bandwidth delay product) (or c-delay-target, which may be trickier to tune). And then forget about "rate" (without c-*), it is used as initial guess only (as long as this rate controller is active, aka c-plan-ahead != 0). -- : Lars Ellenberg : LINBIT | Your Way to High Availability : DRBD/HA support and consulting http://www.linbit.com