[DRBD-user] Sync its so slow

Igor Neves igor at 3gnt.net
Wed Oct 24 11:21:52 CEST 2007

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


Hi,

On Tue, 23 Oct 2007 14:52:33 -0400 (EDT)
Nate Seif <seifn at rstechnicalservices.com> wrote:

> Identify where the bottleneck is to [possibly] get faster sync speeds:
> (1) Check to make sure your kernel has proper [driver] support for
> your chipset. Run 'lspci' to get info about what chipset you have if
> you don't already know.

I have support, and i have full support for the device.

> (2) Make sure you have DMA enabled for your hard drives. Research
> first, then run 'hdparm' to test write speeds to see if hard drives
> are the bottleneck.

DMA in my case, have nothing to do with it, it's SAS device.

> (3) Check your network: can you get faster transfer speeds with other 
> app's? Make sure you've got the proper drivers for your NIC's...

I get much faster transfer on my NIC's, yes, i have tested with iperf.

> 
> Good luck.

Thanks.

> 
> Nate
> 
> 
> On Tue, 23 Oct 2007, Igor Neves wrote:
> 
> > Hi,
> >
> > I'm having problems with sync, using drbd 8.0.4, in centos 5.0.
> >
> > When i have to do one full sync, of the disc, it takes me 12 Hours
> > (500G).
> >
> > The 2 nodes are connected between Gigabit Ethernet, my question
> > it's, what do i have to do, to make it faster? This time is
> > insane! :)
> >
> > I know my disk does not write at Gigabit ethernet capacity, but
> > indeed, lets say it writes at least at 50MBytes/sec.
> >
> > If we write data, at 50MBytes/sec it should take theoretically about
> > 1.66 hours, its about 1h and 40 minutes or so.
> >
> > Of course the disk writes faster than that, at least in this case i
> > have one SAS controller with 15k rpm disk's.
> >
> > I have in drbd.conf configured 'rate 100M'.
> >
> > I have drbd over the disk, and ext3 over it, but i think this is
> > transparent for drbd, this should not take the drbd to slow.
> >
> > When it is doing the full sync, i see in '/proc/drbd' and it says
> > it's copying at about 20K/sec, and since it is in bits, it is
> > pretty slow.
> >
> > This is bug? Or I am the bug? :) Since I'm new to drbd, i think the
> > second option will be more likely then the first one! :D
> >
> > Gigabit Ethernet = 125MBytes/Sec
> >
> > Thanks for all the help.
> > ---------
> > Igor Neves <igor.neves at 3gnt.net>
> > 3GNTW - Tecnologias de Informação, Lda
> >
> > sip igor at 3gnt.net 	jid igor at jabber.3gnt.org
> > icq 249075444		tlm 00351914503611
> >
> > _______________________________________________
> > drbd-user mailing list
> > drbd-user at lists.linbit.com
> > http://lists.linbit.com/mailman/listinfo/drbd-user
> >


---------
Igor Neves <igor.neves at 3gnt.net>
3GNTW - Tecnologias de Informação, Lda
 
 sip igor at 3gnt.net 	jid igor at jabber.3gnt.org
 icq 249075444		tlm 00351914503611




More information about the drbd-user mailing list