Hello all,
For completeness here is my current setup:
host1: Xeon Quad-Core 8GB RAM Centos 5.3 64bit 2x 1TB seagate sata disks in software raid level 1 LVM on top of the raid for dom0 root fs and for all domU root FSses
host2: Xeon Dual-Core 8GB RAM Centos 5.3 64bit 2x 1TB seagate sata disks in software raid level 1 LVM on top of the raid for dom0 root fs and for all domU root FSses
common: hosts are connected to local LAN and directly to each other with a CAT6 gigabit crossover.
I have 6 DRBDs running for 5 domUs over the back to back link. DRBD version drbd82-8.2.6-1.el5.centos _______________________________________________________________________ _______________________________________________________________________
Ok, here is what I have done:
_______________________________________________________________________ I have added the following to the drbd config: disk { no-disk-flushes; no-md-flushes; }
That made the resync go up to 50MB/sec after I issued a drbdsetup /dev/drbdX syncer -r 110M
It used to stick around at 11MB/sec
As far as i can tell it has improved the domUs disk access as well.
I do see that there are a lot of warnings to be heeded with disk and metadata flushing...... _______________________________________________________________________
iperf results:
on host 1: # iperf -s ------------------------------------------------------------ Server listening on TCP port 5001 TCP window size: 85.3 KByte (default) ------------------------------------------------------------ [ 5] local 10.99.99.1 port 5001 connected with 10.99.99.2 port 58183 [ ID] Interval Transfer Bandwidth [ 5] 0.0-10.0 sec 1.16 GBytes 990 Mbits/sec
on host 2: # iperf -c 10.99.99.1 ------------------------------------------------------------ Client connecting to 10.99.99.1, TCP port 5001 TCP window size: 73.8 KByte (default) ------------------------------------------------------------ [ 3] local 10.99.99.2 port 58183 connected with 10.99.99.1 port 5001 [ ID] Interval Transfer Bandwidth [ 3] 0.0-10.0 sec 1.16 GBytes 992 Mbits/sec
I am assuming those results are to be expected from a back to back gigabit. _______________________________________________________________________
the dd thing. I think I did this completely wrong, how is this supposed to be done?
this is what i did
host 1: nc -l 8123 | dd of=/mnt/data/1gig.file oflag=direct (/mnt/data is an ext3 FS in LVM mounted on dom0)
host 2: date; dd if=/dev/zero bs=1M count=1000 | nc 10.99.99.2 8123 ; date
I did not wait for it to finish... according to ifstat the average speed I got during this transfer was 1.6MB/sec
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Any tips would be greatly appreciated.
Kind regards, Coert