[DRBD-user] Poor fsync performance

Nik Martin nik.martin at nfinausa.com
Fri Jan 11 20:56:32 CET 2013

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

On 01/11/2013 08:10 AM, Andy Dills wrote:
> On Fri, 11 Jan 2013, Shaun Thomas wrote:
>> On 01/10/2013 11:49 PM, Andy Dills wrote:
>>> So, it seems to me that even with the no-disk-barrier and no-disk-flushes,
>>> when I am connected, I am limited (write speed) to the speed of the
>>> network connection.
>> These options are only so you're not *also* constrained by buffer flushing and
>> barrier operations. In the default protocol C, all writes must be synced on
>> both nodes before they're successful. That means your writes will be, at most,
>> the speed of your network interface.
>> We use dual 10Gb NICs on all of our servers, and bond them to separate
>> switches for redundancy. I didn't want to go overboard so I gave DRBD a
>> bandwidth limit, but I can get 350MBps from each of the 2 DRBD devices I have
>> set up on our servers, and have plenty left over.
>> I really wouldn't suggest running DRBD *without* a 10Gb NIC.
> Thank you, this is what I was starting to suspect, but hadn't seen
> explicitly stated anywhere.
> Any positive recommendations on 10Gb NICs?

We use Intel x520 DA2 SFP+ cards and they are excellent.
> Andy
> ---
> Andy Dills
> Xecunet, Inc.
> www.xecu.net
> 301-682-9972
> ---
> _______________________________________________
> drbd-user mailing list
> drbd-user at lists.linbit.com
> http://lists.linbit.com/mailman/listinfo/drbd-user




Nik Martin
nfina Technologies, Inc.
+ x1003
Relentless Reliability

More information about the drbd-user mailing list