ZFS on a single disk?

[Jeremy Chadwick]

On Wed, Mar 02, 2011 at 10:28:50AM +0000, Dr Josef Karthauser wrote:
> On 2 Mar 2011, at 00:16, Jeremy Chadwick wrote:
> 
> > Do not disable the ZIL.  I hate referring to the Solaris documentation
> > for FreeBSD, but it applies:
> > 
> > http://www.solarisinternals.com/wiki/index.php/ZFS_Evil_Tuning_Guide#Disabling_the_ZIL_.28Don.27t.29
> > 
> > And you cannot disable the ARC, so just tune it appropriately (which
> > you'll need to do on FreeBSD anyway).  In fact, by getting rid of the
> > ARC (as you proposed), you would suffer worse performance than if you
> > had it in use.
> 
> I guess I should have been a bit clearer, I mean without any external
> devices backing them. Seeing as this is to be running on a VPS/Xen at
> a hosting environment I'm not able to add any additional devices. I'm
> not memory starved however. Is it madness to use a memory disk? (The
> instance in question will have 6gb of ram total to play with.).

Again: don't disable the ZIL, and adjust the ARC to whatever size you
want using a combo of vm.kmem_size and vfs.zfs.arc_max.  Make use of the
RAM you have available to you.  :-)

-- 
| Jeremy Chadwick                                   jdc at parodius.com |
| Parodius Networking                       http://www.parodius.com/ |
| UNIX Systems Administrator                  Mountain View, CA, USA |
| Making life hard for others since 1977.               PGP 4BD6C0CB |