[ On Thursday, June 20, 2002 at 16:15:36 (+0200), Wojciech Puchar wrote: ]
> Subject: Re: I/O priorities
>
> why partitions should matter at all???

Traditionally in the Unix tuning bag of tricks partitions can also be a
way of grouping writes to more constrained areas of the disk.  If your
disk has a lot of cylinders, and is slower to seek the more cylinders it
has to move, then keeping active processes on one partition, or close
partitions, can be a big win.  You also traditionally wanted to put the
buysiest partition (eg. swap and/or /var) in the middle, with

Commercial unix systems come with (or at least used to have) a disk
profiler that could graph the I/O activity on a given disk spindle by
cylinder.  You could see some pretty stunning results sometimes.

(Obviously it's almost always better to use more spindles than it is to
try and group busy cylinders together.)

-- 
								Greg A. Woods

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