Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
Hello,
we use two Citrix XenServer 5.5 with DRBD and DRBD-Proxy and we have
very low write performance on local disks
Tests with bonnie++ in a Debian VM show these results:
(bonnie with drbd and primary/secondary uptodate)
Version 1.03 ------Sequential Output------ --Sequential Input-
--Random-
-Per Chr- --Block-- -Rewrite- -Per Chr- --Block--
--Seeks--
Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP
/sec %CP
test 512M 13325 22 12646 1 275 0 46463 34 129431 1
2.4 0
------Sequential Create------ --------Random
Create--------
-Create-- --Read--- -Delete-- -Create-- --Read---
-Delete--
files /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP
/sec %CP
16 +++++ +++ +++++ +++ +++++ +++ +++++ +++ +++++ +++
+++++ +++
test,512M,13325,22,12646,1,275,0,46463,34,129431,1,2.4,0,16,+++++,+++,+++++,+++,+++++,+++,+++++,+++,+++++,+++,+++++,+++
The VM’s (Windows Server 2000) are very slow and hang sometimes.
Without DRBD we easily reach 100 MB/s (rw).
Strangely while the HDDs on the primary are active only sometimes the
secondary HDDs are permanently in use and there is a lot of traffic on
the DRBD network.
We use an extra NIC for DRBD on both servers and the connection for DRBD
is a SDSL with 2MBit sym.
dom0 is configured to use 2048MB (parameter dom0_mem).
Any ideas what to look for? Any help is highly appreciated!
Here is our /etc/drbd.conf:
global { usage-count yes; }
common {
protocol A;
net {
shared-secret "xenserver";
after-sb-0pri discard-zero-changes;
after-sb-1pri consensus;
after-sb-2pri disconnect;
ping-timeout 20;
}
disk {
max-bio-bvecs 1;
}
startup {
# leave this disabled for now
become-primary-on bornheim;
}
handlers {
split-brain "/usr/lib/drbd/notify-split-brain.sh";
}
syncer { rate 284k; }
}
resource drbd-sr {
device /dev/drbd1;
disk /dev/sda3;
meta-disk internal;
syncer {
csums-alg md5;
}
proxy {
compression on;
memlimit 1024M;
}
on bornheim {
address 127.0.0.1:7789;
proxy on bornheim {
inside 127.0.0.1:7788;
outside 192.168.93.1:7788;
}
}
on koeln {
address 127.0.0.1:7789;
proxy on koeln {
inside 127.0.0.1:7788;
outside 192.168.94.1:7788;
}
}
}
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 552 bytes
Desc: OpenPGP digital signature
URL: <http://lists.linbit.com/pipermail/drbd-user/attachments/20100317/9426f063/attachment.pgp>