Re: [Moosefs-users] Best FileSystem for chunkers.

[Steve W. <st...@pu...>]

On 05/17/2012 03:26 PM, Atom Powers wrote:
> On 05/17/2012 11:56 AM, Steve Wilson wrote:
>> I'd like to know if anyone has tried a file system with compression like
>> ZFS on Linux.  Some have mentioned that it might yield a performance
>> improvement.  I might give it a try on our next pair of chunk servers
>> but it would be good to know if anyone else has gone this route before
>> and what their experience has been.
> I use ZFS on FreeBSD, which is one of the main reasons I use FreeBSD on
> my chunk servers.
>
> Good:
> * Compression, 1.16x in my environment
I don't know if 1.16x would give me much improvement in performance.  I 
typically see about 1.4x on my ZFS backup servers which made me think 
that this reduction in disk I/O could result in improved overall 
performance for MooseFS.
> * zraid
> * probably improved performance (I haven't done a comparison on MooseFS
> but saw better performance over UFS for "standard" file system use)
> * Easy to carve up for other uses on the same server
>
> Bad:
> * high RAM requirement
Is the high RAM due to using raidz{2-3}?  I was thinking of making each 
disk a separate ZFS volume and then letting MooseFS combine the disks 
into an MFS volume (i.e., no raidz).  I realize that greater performance 
could be achieved by striping across disks in the chunk servers but I'm 
willing to trade off that performance gain for higher redundancy (in the 
case of using simple striping) and/or greater capacity (in the case of 
using raidz, raidz2, or raidz3).

>
> Ugly:
> * FreeBSD is tricky to build with bootable ZFS
> * Linux ZFS is FUSE.

If someone is using Linux, I would definitely recommend the ZFS native 
on Linux port (http://zfsonlinux.org/) rather than the FUSE version of 
ZFS.  I've been using it for my backup servers for about six months now 
and with very good success.

Steve