Re: disk partition schemes
On Saturday 23 June 2001 21:13, Nick Jennings wrote:
> > However if you have a single large partition then when you are
> > writing data the FS drivers can optimise things.
> I always thought that this was a performance hit, I know I've read it
> in places before, but I can't seem to find them as I look right now.
If you are using an older kernel (say 2.0 series) on an SMP machine then
this could be true. Older kernels didn't manage SMP very effectively and
often locked other CPUs out of resources. Having two separate file
systems might in some situations allow access to cached data where
otherwise there would be spinlocks to deal with.
I think that 2.4.x has solved most of these issus (and 2.2.x was much
better than 2.0.x).
> > Swap is often the most used partition. Root is probably the least.
> > /tmp and /home are both candidates for the most used partition.
> > Having things separate like this means that in many common usage
> > situations you'll have the heads seeking across the entire disk all
> > the time. Having a single partition could increase performance...
> Good point, I've put / at the beginning just out of habit, put I think
Same here. But 1-2 G at the start being reserved for a low utilization
partition such as root doesn't matter much on a modern 40G+ drive IMHO.
> that, especially on a server, /var is much more used than home is. and
> /usr is where every application is executed from, that's gotta count
> for something. I would venture to say that, on a server thats not
> offering lots of shell accounts, /home is the least used.
If the server is an IMAP server then home can still be most used. But
really trying to make generalisations about what a "server" does isn't a
good idea. There's too many types of servers.
> > If sticking another disk in is so easy then why not just install lots
> > of disks in a RAID array from the start? That'll get the best
> > performance...
> Well because a hardware RAID is more expensive than a scsi or ide
> drive. Also because I'm thinking of one disk, with the possible
> expansion onto another one, or two. not starting out with several.
Software RAID is cheap and easy...
http://www.coker.com.au/bonnie++/ Bonnie++ hard drive benchmark
http://www.coker.com.au/postal/ Postal SMTP/POP benchmark
http://www.coker.com.au/projects.html Projects I am working on
http://www.coker.com.au/~russell/ My home page