Re: Swap initialised as an md?
From: Bill Davidsen <hidden>
Date: 2007-03-26 03:45:53
Michael Tokarev wrote:
Bill Davidsen wrote: []quoted
If you use RAID0 on an array it will be faster (usually) than just partitions, but any process with swapped pages will crash if you lose either drive. With RAID1 operation will be more reliable but no faster. If you use RAID10 the array will be faster and more reliable, but most recovery CDs don't know about RAID10 swap. Any reliable swap will also have the array size smaller than the sum of the partitions (you knew that).You seems to forgot to mention 2 more things: o swap isn't usually needed for recovery CDs
That's system dependent, but at least two report problems with swap if configured as RAID10. Confusing error messages are not a plus when you get to the stage of using a recovery CD. The need for swap depends on configuration.
o kernel vm subsystem already can do equivalent of raid0 for swap internally, by means of allocating several block devices for swap space with the same priority. If reliability (of swapped processes) is important, one can create several RAID1 arrays and "raid0 them" using regular vm techniques. The result will be RAID10 for swap.
Sorry, no. It will be RAID0+1, not the same thing. See RAID10 description. -- bill davidsen [off-list ref] CTO TMR Associates, Inc Doing interesting things with small computers since 1979