[Gllug] To partition or not to partition

[John Edwards]

On Thu, Oct 14, 2010 at 02:23:00PM +0100, John Hearns wrote:
> On 13 October 2010 16:18, Tethys <sta296 at astradyne.co.uk> wrote:
>> --------
>>
>> John Edwards writes:
>>
>>>Are there any performance hits for swap on LVM on RAID?
>>
>> Swapping is itself so glacially slow that any extra overhead
>> added by LVM or RAID will be utterly irrelevant. If you're
>> worried about performance, then build your machine so that
>> it doesn't swap in the first place.

It's an Java application that does not get used regularly.
The machines were built about 3 years ago and are not really
worth upgrading before they will be replaced.


> LVM or RAID? Hah. Real Men (TM) use swap over iSCSI.

What about using LVM on those iSCSI devices?

Or would you put the iSCSI targets on LVM (on RAID) and resize them
on the iSCSI server/array?

In other words should iSCSI targets be treated as whole disk or
filesystems? I suspect filesystems would be more efficent.


> 'Tis not as barking mad as it sounds - consider if you will a rack
> full of diskless compute blades.

Not daft at all. LTS (Linux Terminal Services) uses nbd for swap
on diskless machines. Swap may be slow, but it's better than having
the kernel use oom-killer to kill running programs.

Except that in this case instead of a nice shiny Gigabit Ethernet the
machines are at remote office locations, some of which have slow ADSL
links. Combined with all the other VPN and Internet traffic, it could
get very messy. I think I'll stick with throwing a few spare GB of
hard disk at the problem.


-- 
#---------------------------------------------------------#
|    John Edwards   Email: john at cornerstonelinux.co.uk    |
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