[DRBD-user] Speed Sync seems to be limited on gigabit ethernet

[Marcello Lupo]

Hi,
some times i get more speed than 12MB/sec. Some times i reach peak of 
15/18 Mb/sec and the average speed is around 15Mb/sec.
Before the 2 interfaces where connected with 100Mbit switch (while 
waiting for the gigabit) and data was constant to 12Mb/sec.
After switch changed to Gigabit i got improvements of performances but 
very few.
The data is going on the right interface. I checked it during the sync 
with ifconfig.
I tried to start both resources sync at the same time and i get results 
as this:

version: 0.7.21 (api:79/proto:74)
SVN Revision: 2341 build by lmb at dale, 2006-08-10 14:19:54
 0: cs:SyncSource st:Primary/Secondary ld:Consistent
    ns:5254172 nr:0 dw:0 dr:5262256 al:0 bm:320 lo:33 pe:190 ua:2021 ap:0
        [==>.................] sync'ed: 11.9% (38090/43221)M
        finish: 0:59:33 speed: 10,900 (11,724) K/sec
 1: cs:SyncSource st:Primary/Secondary ld:Consistent
    ns:2488968 nr:0 dw:0 dr:2496960 al:0 bm:151 lo:0 pe:176 ua:1998 ap:0
        [>...................] sync'ed:  4.3% (54919/57349)M
        finish: 1:13:59 speed: 12,552 (9,080) K/sec

So the speed seems to be able to reach at least 20Mb/sec. The problem 
seems to be that it is not stable.
Maybe a RAID problem.
I will try with protocol B too.

This is my config:

resource smtp {
        protocol C;
        startup {
                degr-wfc-timeout 120;
        }
        disk {
                on-io-error detach;
        }
        net {
                ko-count 8;
                on-disconnect reconnect;
        }
        syncer {
                rate   100M;
        }
        on host0 {
                device     /dev/drbd0;
                disk       /dev/cciss/c0d0p5;
                address    10.9.9.1:7788;
                meta-disk  /dev/cciss/c0d0p7[0];
        }
        on host1 {
                device     /dev/drbd0;
                disk       /dev/cciss/c0d0p5;
                address    10.9.9.2:7788;
                meta-disk  /dev/cciss/c0d0p7[0];
        }
}

resource web{
        protocol C;
        startup {
                degr-wfc-timeout 120;
        }
        disk {
                on-io-error detach;
        }
        net {
                ko-count 8;
                on-disconnect reconnect;
        }
        syncer {
                rate   100M;
        }
        on host0 {
                device     /dev/drbd1;
                disk       /dev/cciss/c0d0p6;
                address    10.9.9.1:7790;
                meta-disk  /dev/cciss/c0d0p7[1];
        }
        on host1 {
                device     /dev/drbd1;
                disk       /dev/cciss/c0d0p6;
                address    10.9.9.2:7790;
                meta-disk  /dev/cciss/c0d0p7[1];
        }
}



Thank you for help.
Bye,
Marcello