Re: swap priorities
Glenn McGrath <Glenn.McGrath@jcu.edu.au> writes:
> Im a bit confused.
> I just created two swap files with the boot floppies, the first swap
> file (28MB) has priority -1, and the second swap file i made (64MB) has
> a priority -2.
> On my systems i currently have 4 swap files (4 drives) and as i
> understoop making them the same priority enabled the kernel to use them
> in parallel (raid like). I assigned mine all priority of 1.
> I looked at man swapon and it says the priority can be anything between
> 0 and 32767.
> So two questions
> 1) Should the swap priorities be a positive value.
Hmm, according to the manpage it must be positive.
> 2) Should the priorities of multiple swap files be the same.
If you have 4 equally fast harddrives that don´t slowdown each other
you should give them all the same priority. If one is slower or slows
any other give that a lower priority. From "man 2 swapon":
Swap pages are allocated from areas in priority order,
highest priority first. For areas with different priori
ties, a higher-priority area is exhausted before using a
lower-priority area. If two or more areas have the same
priority, and it is the highest priority available, pages
are allocated on a round-robin basis between them.
If you have all partitions with the same priority they will be used
equally (roughly) and thus give a good speed.
May the Source be with you.