Re: [Moosefs-users] SSDs

[Steve T. <sm...@cb...>]

On Fri, 30 Mar 2012, Chris Picton wrote:

> Do those servers have bettery backed cache on the raid?  If so, are they set 
> to write-back or write-through?
>
> I have found that when running on standard SATA disks, the constant fsync is 
> what slows things down tremendously.  A battery backed write-back cache on 
> the raid card would help a lot there.

Yes, the controllers (Perc 5's and Perc 6's) have battery backup, and the
virtual disks are set to write back. Indeed, write through (such as when 
the battery is doing a learn cycle) is a great deal slower.

Steve