Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
Thanks for your suggestions.
I think the problem has something to do with the fact that i am using
loopback device with DRBD. The problem disappears when i use a separate
partition with DRBD.
dbarker wrote:
>
> a) use oflag=direct or dd will just test caching.
> b) You show a 183MB/s rate, which is pretty good. However, the target
> appears not to be the drbd volume, you don't say if the resource is
> connected or waiting for connection, and you don't describe the underlying
> hardware.
> c) How is /mnt/mysql/syncing_drbd related to opt/drbd-test.loop or
> /dev/drdb1?
>
> Dan (the top poster)
>
> -----Original Message-----
> From: drbd-user-bounces at lists.linbit.com
> [mailto:drbd-user-bounces at lists.linbit.com] On Behalf Of rahulcs
> Sent: Tuesday, September 11, 2012 4:43 PM
> To: drbd-user at lists.linbit.com
> Subject: [DRBD-user] slow write performance
>
>
> Hi,
> I am using DRBD for syncing files between two machines on a LAN. I have
> created a device on a file using dd if=/dev/zero of=/opt/drbd-test.loop
> bs=1M count=200
> losetup /dev/loop1 /opt/drbd-test.loop.
>
> My drbd resource settings are as follows:
> root at obelix101:/tmp# drbdsetup 1 show
> disk {
> size 0s _is_default; # bytes
> on-io-error pass_on _is_default;
> fencing dont-care _is_default;
> max-bio-bvecs 0 _is_default;
> }
> net {
> timeout 60 _is_default; # 1/10 seconds
> max-epoch-size 8000;
> max-buffers 8000;
> unplug-watermark 16;
> connect-int 10 _is_default; # seconds
> ping-int 10 _is_default; # seconds
> sndbuf-size 0 _is_default; # bytes
> rcvbuf-size 0 _is_default; # bytes
> ko-count 0 _is_default;
> after-sb-0pri disconnect _is_default;
> after-sb-1pri disconnect _is_default;
> after-sb-2pri disconnect _is_default;
> rr-conflict disconnect _is_default;
> ping-timeout 5 _is_default; # 1/10 seconds
> on-congestion block _is_default;
> congestion-fill 0s _is_default; # byte
> congestion-extents 127 _is_default;
> }
> syncer {
> rate 1024000k; # bytes/second
> after -1 _is_default;
> al-extents 3389;
> on-no-data-accessible io-error _is_default;
> c-plan-ahead 0 _is_default; # 1/10 seconds
> c-delay-target 10 _is_default; # 1/10 seconds
> c-fill-target 0s _is_default; # bytes
> c-max-rate 102400k _is_default; # bytes/second
> c-min-rate 4096k _is_default; # bytes/second
> }
> protocol C;
> _this_host {
> device minor 1;
> disk "/dev/loop1";
> meta-disk internal;
> address ipv4 192.168.245.101:7789;
> }
> _remote_host {
> address ipv4 192.168.245.102:7789;
> }
>
> I am getting really bad write performance:
>
> root at obelix101:/tmp# time dd if=/dev/zero of=/mnt/mysql/syncing_drbd bs=1M
> count=12
> 12+0 records in
> 12+0 records out
> 12582912 bytes (13 MB) copied, 0.0686793 s, 183 MB/s
>
> real 3m49.773s
> user 0m0.000s
> sys 0m0.168s
>
> What am i doing wrong ?
>
> Thanking you,
> Rahul
> --
> View this message in context:
> http://old.nabble.com/slow-write-performance-tp34419641p34419641.html
> Sent from the DRBD - User mailing list archive at Nabble.com.
>
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>
--
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