Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
Hi all,
I read article about DRBD 8.4.3 and performance improvement in random
tests:
http://blogs.linbit.com/p/469/843-random-writes-faster/
I compared DRBD 8.3.10 and 8.4.3 and achieved strange results.
* 300GB volume synchronization time:
DRBD 8.3.10 - 00:18:24
DRBD 8.4.3 - 00:52:06
* Sequence 300GB write time (DD)
DRBD 8.3.10 - 00:42:12
DRBD 8.4.3 - 00:37:37
* Random write test time (FIO)
DRBD 8.3.10 - 03:19:07
DRBD 8.4.3 - more than 1 day (after 3 hours interrupted)
Last test confirms that DRBD 8.4.3 is better than 8.3.10 in random
test, but synchronization time is disturbing.
Why synchronization time is more than 2 times faster on DRBD 8.3.10?
What can I improve in my configuration?
System Information
Manufacturer: Supermicro (2x)
Product Name: X8DTS
root at test1:~# free
total used free shared buffers
cached
Mem: 12319608 1051876 11267732 0 34768
524984
-/+ buffers/cache: 492124 11827484
Swap: 4194300 0 4194300
CPU: Intel(R) Xeon(R) CPU E5504 @ 2.00GHz (4x)
DRBD configuration:
root at test1:~# cat /etc/drbd.conf
global {
disable-ip-verification;
usage-count no;
}
resource "r1" {
protocol C;
device minor 0;
on test1 {
disk "/dev/vg0/lv0";
address 10.0.0.2:12000;
meta-disk "/dev/vg0/lv_m0"[0];
}
net {
max-buffers 2048;
max-epoch-size 2048;
unplug-watermark 128;
sndbuf-size 0;
ping-int 4;
timeout 30;
}
handlers {
local-io-error "/opt/ioerror_handler
lv0,vg0,sdb.";
}
on test2 {
disk "/dev/vg0/lv0";
address 10.0.0.1:12000;
meta-disk "/dev/vg0/lv_m0"[0];
}
syncer {
c-min-rate 600M;
rate 600M;
al-extents 127;
}
disk {
on-io-error call-local-io-error;
fencing resource-only;
}
}
"
root at test1:~# cat /opt/fio/random.job
[global]
randrepeat=1
ioengine=libaio
bs=1k
ba=1k
size=8G
direct=1
gtod_reduce=1
norandommap
iodepth=64
filename=/dev/drbd0
nice=-19
[write]
blocksize=1k
loops=1
rw=randwrite
stonewall
[read]
blocksize=1k
loops=1
rw=randread
stonewall"
--
Pozdrawiam,
Grzegorz Wolny
KRINNER POLSKA Sp. z o.o.
Skrytka Pocztowa 1107
40-001 Katowice
http://krinner.info.pl
e-mail: grzegorz.wolny at krinner.info.pl