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, 10 Dec 2005 14:57:01 +0100 Lars Ellenberg <Lars.Ellenberg at linbit.com> wrote: > / 2005-12-10 07:39:34 -0500 > \ Brad Barnett: > > > > > > > > > > Ok, my drbd rebuild is complete, and I can do some testing this > > weekend at specific planned times. > > > > Before I do, I'd like to ask a few questions. I might as well try to > > tune drbd as best as I can, beforehand. ;) > > > > Anyhow, as far as I can tell, the syncer seems to be for the sync > > process ... and not normal data transfer between the two drbd nodes? > > I ask, because I actually had to turn off my full sync process during > > the day, as nfs access dropped to approximately 1/50th the speed with > > it on. > > > > Is the sync process supposed to "give way" to the normal data updates > > between the nodes? Or, during a full sync, does drbd store local > > changes on the primary.. and just ignore sending anything to the > > secondary? > > Syncer access and application writes are concurrent. > They are not prioritized. This is on the wishlist, though. > You "give way" by setting the sync rate to something lower than your > actual bandwith, thereby "reserving" the rest of the bandwidth for your > applications. Ok, great... so I can set this relatively low, and sync over three days instead of one... and have lots of bandwidth left. Bonus. > > BTW, you won't see a Full Sync with drbd 0.7 and later, except for the > initial one, or in case one of the lower level storages gets physically > replaced, and you _request_ a full sync again by invalidating that > device. True.. but I'm going to be doing some testing on the problem I found earlier, to see if I can duplicate it and find the source. I'll probably do a few full syncs when doing so, so I just want to get it running smoothly.. > > > If so, why was my access so slow during that full sync? I tried > > reducing my sync from 700000k to 250000k, but I saw no difference in > > Note that we are storage guys, not network guys. > So think storage. > This rate is given in Byte, not Bit. > I seriously doubt your hardware can > do sustained 250 Mega Byte transfer rate. > Ah.. ok. Thanks.. I suppose you would have used b for bit, if that was the case anyhow.. but unfortunately I see B and b used incorrectly so often, I just assume bit now. :/ My mistake. > > syncer rate/performance. I have a crossover cable between two gigabit > > network devices.. and dmesg as well as ethtool confirms this. > > > > Any suggests for better usage while sync is happening.. or ways to > > tune this baby? > > -- > : Lars Ellenberg Tel +43-1-8178292-0 : > : LINBIT Information Technologies GmbH Fax +43-1-8178292-82 : > : Schoenbrunner Str. 244, A-1120 Vienna/Europe http://www.linbit.com : > __ > please use the "List-Reply" function of your email client. > _______________________________________________ > drbd-user mailing list > drbd-user at lists.linbit.com > http://lists.linbit.com/mailman/listinfo/drbd-user