Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
Hey Phillip, I upgraded to 8.4.4 and it totally resolved my issue. My targets went from 0.5 - 1.1M/sec writes to 30M/sec writes on random writes and 7M/sec (with caching turned on) to 85M/sec (with no caching!). Thank you so much, I couldn't be happier. - Bret On Thu, Jun 5, 2014 at 3:34 AM, Philipp Marek <philipp.marek at linbit.com> wrote: > Hi Bret, > > > Intel(R) Xeon(R) CPU E3-1230 V2 @ 3.30GH > > CentoS 6.5 - 2.6.32-431.17.1.el6.x86_64 > > drbd version: 8.3.16 (api:88/proto:86-97) > please use 8.4.4 (or .5). > Eg because of http://blogs.linbit.com/p/469/843-random-writes-faster/ > > > > dd if=/dev/zero of=./testbin bs=512 count=1000 oflag=direct > > 512000 bytes (512 kB) copied, 32.3254 s, 15.8 kB/s > This means ~32msec per write. > > But: you're writing into a _filesystem_, not directly onto the DRBD > resource. > And that means quite some write amplification - each 512 byte write > _might_ result (depending on the filesystem) in _multiple_ write- > requests, each with a separate barrier ... > > > Please try writing into a DRBD device, without any filesystem inbetween; > and using 4kB blocks might help to avoid read/modify/write cycles, too. > > > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.linbit.com/pipermail/drbd-user/attachments/20140605/bf39e3bb/attachment.htm>