[DRBD-user] link aggregate ( bonding module )
dbourque at weatherdata.com
Tue Apr 21 20:58:59 CEST 2009
the read speed is actually higher according to hdparm:
[root at box1 bonnie]# hdparm -tT /dev/sdb
Timing cached reads: 17608 MB in 2.00 seconds = 8813.98 MB/sec
Timing buffered disk reads: 1124 MB in 3.00 seconds = 374.38 MB/sec
makes me wonder about the accuracy of Bonnie...
Sr. Systems Engineer
WeatherData Service Inc
An Accuweather Company
Tom Brown wrote:
> On Tue, 21 Apr 2009, Daniel Bourque wrote:
>> My disk writes are benching 2x faster than the GigE dedicated link
>> connecting the DRBD nodes.
>> [root at host1 ]# ./Bonnie -s 1000 -d /var/tmp/
> a 1 gig test file? That's probably a bit small. I'd guess you've got
> at least a gig of memory in the system... and that might be why your
> write speads are faster than your read speeds? (and why your cpu usage
> is so high?) I'd make sure your benchmark is valid before you
> re-engineer your network.
> obviously I'm just looking in from the outside, and maybe your test is
> completely valid. but writes that are faster than reads is unusual
> unless it is being cached somewhere...
>> Bonnie 1.4: File '/var/tmp//Bonnie.9328', size: 1048576000, volumes: 1
>> Writing with putc()... done: 50862 kB/s 99.7 %CPU
>> Rewriting... done: 732229 kB/s 100.0 %CPU
>> Writing intelligently... done: 248780 kB/s 54.9 %CPU
>> Reading with getc()... done: 43119 kB/s 99.9 %CPU
>> Reading intelligently... done: 2002381 kB/s 99.9 %CPU
>> Thus, the DRBD link creates a bottleneck for disk writes. I would like
>> to use 802.3ad Dynamic link aggregation but looks like DRBD works off 2
>> unidirectional tcp/ip sessions, making it unable to max out the 2
>> gigE link.
>> Does anyone have any suggestion ( other than buying a pair of 10gigE
>> NICs ) ?
>> Daniel Bourque
>> Sr. Systems Engineer
>> WeatherData Service Inc
>> An Accuweather Company
>> drbd-user mailing list
>> drbd-user at lists.linbit.com
> tbrown at BareMetal.com | Courage is doing what you're afraid to do.
> http://BareMetal.com/ | There can be no courage unless you're scared.
> | - Eddie Rickenbacker
More information about the drbd-user