[DRBD-user] blocking I/O with drbd

Felix Frank ff at mpexnet.de
Mon Dec 19 16:22:09 CET 2011

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


I may be going blind, but I still fail to find the type of network
adapter in use.

On 12/19/2011 04:06 PM, Volker wrote:
> about 35-40MB/s
> $ scp test-data.dd root at fallback:
> test-data.dd       100%  392MB  39.2MB/s   00:10

SCP isn't a very good test, because you get a lot of overhead for
encryption. Still, this is way below what you seem to expect from your
disk. How ist DRBD supposed to move more than 50MBps through your network?

> 64 bytes from fallback.content.domain.de.de ( icmp_seq=3
> ttl=64 time=0.093 ms

On a LAN, this is pretty serious latency. Don't expect DRBD to be
whizzing fast in this environment.
You *may* try and opt for protocol B to see if that helps latency, but
you won't solve your throughput issues.

Sorry for bearing bad news, maybe someone else can help some.

You should have read of http://www.drbd.org/users-guide/ch-benchmark.html


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