Using an SSD "disk" for /

[Jeremy Chadwick]

On Wed, Nov 03, 2010 at 08:35:21PM +0100, Ronald Klop wrote:
> On Wed, 03 Nov 2010 18:39:35 +0100, Tom Evans
> <tevans.uk at googlemail.com> wrote:
> 
> >On Wed, Nov 3, 2010 at 1:34 PM, Pete French
> ><petefrench at ticketswitch.com> wrote:
> >>I boot a server from a Compact Flash drive connected to a CF->SATA
> >>adaptor. Its only 4GB, enough to boot, and then all my read/write
> >>partititons come from several terrabytes of attached zpool. It
> >>works excellently, and was very cheap to setup. Performance is
> >>fine as you are almost never writing to the flash drive. The only
> >>time I notice the slowdown is when doing an installworld or
> >>installkernel.
> >>
> >>-pete.
> >>
> >
> >When you set up your disks like this, where do you put your swap?
> >
> >For my home ZFS server - which has a tank with two raidz pools, each
> >with 6 disks in - I partitioned the first 6 disks into 2 partitions, a
> >6 GB chunk at the start, and the remaining data used for zfs. I then
> >use 3 of the disks first partition in a gmirror UFS root partition,
> >and the other 3 as swap.
> 
> Why do you need swap if the server is doing file serving only? You
> will have more fun if you add more RAM then when you add more swap.

Well, in my case, I'm equally concerned about memory exhaustion
(sometimes programs do spiral out of control!), in addition to the need
for a dump device in the case of a kernel panic.  Pete's situation and
needs are different from mine, but those are the two focal points I have
when it comes to swap and /var's size.

-- 
| 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 |