Mark
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swapfile on RAID, or not?
I've just set up my Linux boot device as a RAID-1. Seems to work OK. I've not been sure about what to do with swap space. Googling turned up this interesting statement http://tldp.org/HOWTO/Software-RAID-HOWTO-2.html
Confused!
There's no reason to use RAID for swap performance reasons. The kernel itself can stripe swapping on several devices, if you just give them the same priority in the /etc/fstab file.Sounds like I don't need my swap partitions inside a RAID. But then in the very next paragraph he says,
A nice /etc/fstab looks like:
/dev/sda2 swap swap defaults,pri=1 0 0
/dev/sdb2 swap swap defaults,pri=1 0 0
:
/dev/sdg2 swap swap defaults,pri=1 0 0
This setup lets the machine swap in parallel on seven SCSI devices. No need for RAID, since this has been a kernel feature for a long time.
Another reason to use RAID for swap is high availability. If you set up a system to boot on eg. a RAID-1 device, the system should be able to survive a disk crash. But if the system has been swapping on the now faulty device, you will for sure be going down. Swapping on a RAID-1 device would solve this problem.Is this contradicting he immediate preceding statement or am I just not reading something right? Which way is he recommending? Are non-RAID swap partitions a good thing or a bad thing?
Confused!
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Yep, you got it.
ASKER
Did it. It works just fine!
ASKER
Therefore, I supposed I need to RAIDify my swap partitions.