On Tue, Jan 5, 2016 at 6:01 PM, Neil Bothwick <n...@digimed.co.uk> wrote: > On Tue, 05 Jan 2016 23:16:48 +0100, lee wrote: > >> > I would run btrfs on bare partitions and use btrfs's raid1 >> > capabilities. You're almost certainly going to get better >> > performance, and you get more data integrity features. >> >> That would require me to set up software raid with mdadm as well, for >> the swap partition. > > There's no need to use RAID for swap, it's not like it contains anything > of permanent importance. Create a swap partition on each disk and let > the kernel use the space as it wants.
So, while I tend not to run swap on RAID, it isn't an uncommon approach because if you don't put swap on raid and you have a drive failure while the system is running, then you are likely to have a kernel panic. Since one of the main goals of RAID is availability, it is logical to put swap on RAID. It is a risk thing. If your system going down suddenly with no loss to data in your regular filesystems isn't a huge problem (maybe this is Google's 10,000th read-only caching server) then by all means don't put swap on RAID. The important thing is to understand the risks and make an informed decision. -- Rich
