[DRBD-user] Standalone drbd Server without secondary is terribly slow

Christoph Adomeit Christoph.Adomeit at gatworks.de
Tue Feb 10 15:02:08 CET 2009

Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.


One or more of these parameters in drbd.conf increased performance
to the expected values, i am satisfied so far and will investigate
later. Maybe it was the sie of 5.6 Terrabytes that made the
drbd disk that slow ?

disk {
  ...
  no-disk-flushes;
  no-md-flushes;
  no-disk-barrier;
}


On Tue, Feb 10, 2009 at 01:18:03PM +0100, Christoph Adomeit wrote:
> 
> Hi,
> 
> I have setup a new node to be a drbd primary.
> 
> Later on I will have a secondary but that hardware is not even 
> delivered to us. However, I wanted to finish the final configuration 
> of the primary node now.
> 
> So I have setup only a primary drbd setup of lvm above drbd, which works
> good. Filtered the disk sdb in lvm.conf for not getting
> lvm to use /dev/sdb instead of /dev/drbd0. Drbd is in standalone mode now.
> 
> However, drbd is terribly slow, that server makes 300 MB/s writes
> on local disk but on top of drbd only 3 MB/s.
> 
> /proc/drbd says:
> version: 8.3.0 (api:88/proto:86-89)
> GIT-hash: 9ba8b93e24d842f0dd3fb1f9b90e8348ddb95829 build by root at san01,
> 2009-02-09 16:18:25
>  0: cs:StandAlone ro:Primary/Unknown ds:UpToDate/DUnknown   r---
>      ns:0 nr:0 dw:1350856 dr:1084 al:926 bm:669 lo:3 pe:0 ua:0 ap:2 ep:1
>      wo:b oos:5819396636
> 
> kernel 2.6.27-11-server from ubuntu, drbd 8.3 hand compiled by me.
> 
> drbd.conf: nothing special
> resource san01cluster {
>   protocol      B;
>     startup {
>     wfc-timeout 10;
>     degr-wfc-timeout    20;
>   }
>   disk { on-io-error detach; }
>   syncer {
>     rate 300M;
>   }
> 
> on san01 {
>   device      /dev/drbd0;
>   disk        /dev/sdb;
>   address     10.65.1.10:7891;
>   meta-disk   internal;
> }
>   on san02 {
>   device      /dev/drbd0;
>   disk        /dev/sdb;
>   address     10.65.1.11:7891;
>   meta-disk   internal;
> }
> }
> 
> 
> root at san01:~# pvdisplay
>   --- Physical volume ---
>     PV Name               /dev/drbd0
>     VG Name               vg0
>     PV Size               5,42 TB / not usable 540,00 KB
>     Allocatable           yes
>     PE Size (KByte)       4096
>     Total PE              1420751
>     Free PE               1395151
>     Allocated PE          25600
>     PV UUID
>     ul9Xjf-6nET-zUb2-b1my-Qb7M-02t8-Ai4CpO
> 
> lvdisplay
> 
> root at san01:~# lvdisplay
>   --- Logical volume ---
>     LV Name                /dev/vg0/images
>     VG Name                vg0
>     LV UUID                aewpzg-cMiC-cFVA-kBGi-2vMW-10Gz-LMs9Mu
>     LV Write Access        read/write
>     LV Status              available
>     # open                 1
>     LV Size                100,00 GB
>     Current LE             25600
>     Segments               1
>     Allocation             inherit
>     Read ahead sectors     auto
>     - currently set to     256
>     Block device           254:0
> 
> 
> writes to /dev/vg0/images ares slow, while writes to sda1, the root
> filesystem are fast, tested with bonnie++
> 
> Any idea what might be the reason for the server being so slow ?
> 
> -- 
> Christoph Adomeit
> GATWORKS GmbH
> Reststrauch 191
> 41199 Moenchengladbach
> Sitz: Moenchengladbach
> Amtsgericht Moenchengladbach, HRB 6303
> Geschaeftsfuehrer:
> Christoph Adomeit, Hans Wilhelm Terstappen
> 
> Christoph.Adomeit at gatworks.de     Internetloesungen vom Feinsten
> Fon. +49 2166 9149-32                      Fax. +49 2166 9149-10
> -- 
> Christoph Adomeit
> GATWORKS GmbH
> Reststrauch 191
> 41199 Moenchengladbach
> Sitz: Moenchengladbach
> Amtsgericht Moenchengladbach, HRB 6303
> Geschaeftsfuehrer:
> Christoph Adomeit, Hans Wilhelm Terstappen
> 
> Christoph.Adomeit at gatworks.de     Internetloesungen vom Feinsten
> Fon. +49 2166 9149-32                      Fax. +49 2166 9149-10
> _______________________________________________
> drbd-user mailing list
> drbd-user at lists.linbit.com
> http://lists.linbit.com/mailman/listinfo/drbd-user

-- 
Christoph Adomeit
GATWORKS GmbH
Reststrauch 191
41199 Moenchengladbach
Sitz: Moenchengladbach
Amtsgericht Moenchengladbach, HRB 6303
Geschaeftsfuehrer:
Christoph Adomeit, Hans Wilhelm Terstappen

Christoph.Adomeit at gatworks.de     Internetloesungen vom Feinsten
Fon. +49 2166 9149-32                      Fax. +49 2166 9149-10



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