[DRBD-user] Re: Why is drbd 0.7.22 slow on Opteron 240EE?

Maurice Volaski mvolaski at aecom.yu.edu
Fri Nov 24 00:31:36 CET 2006

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


When I do the tests below, my results almost look I'm running a 486!

primary (faster, by itself, no drbd involved)
./dm -x -a 0 -s 4g -b 20m -m -y -p -o hello
RRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRr
28.75 MB/sec (4294967296 B / 02:22.454176)

secondary (slower, by itself, no drbd involved)
./dm -x -a 0 -s 4g -b 20m -m -y -p -o hello      
RRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRr
20.77 MB/sec (4294967296 B / 03:17.205593)


I am trying to find a live CD that has the Areca driver compiled in. 
That way I can confirm that the gentoo kernel config is the cause.

By the way, I had trouble trying to perform this test on a drbd 
volume. It complains that it cannot open the output device. And this 
problem goes away if I leave out the -x switch.

>
># /dev/sdc1 (1,5TB) with xfs no drbd
>
>./dm -x -a 0 -s 4g -b 20m -m -y -p -o /mnt/bonnie/dm
>RRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRr
>239.44 MB/sec (4294967296 B / 00:17.106477)
>
># 4,5TB xfs FS, drbd disconnected
>
>./dm -x -a 0 -s 4g -b 20m -m -y -p -o /mnt/bonnie/dm
>RRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRr
>214.32 MB/sec (4294967296 B / 00:19.111477)
>
># 4,5TB xfs FS, drbd connected and in sync
>
>./dm -x -a 0 -s 4g -b 20m -m -y -p -o /mnt/bonnie/dm
>RRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRr
>98.08 MB/sec (4294967296 B / 00:41.761632)
>
>
>The bonnie++ and tiobench benchmarks are in the same area. In my case,
>drbd is mainly limited by the speed of the GbE link.

-- 

Maurice Volaski, mvolaski at aecom.yu.edu
Computing Support, Rose F. Kennedy Center
Albert Einstein College of Medicine of Yeshiva University



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