Re: Swap initialised as an md?

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Michael Tokarev wrote:
Bill Davidsen wrote:
[]
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 <davidsen@xxxxxxx>
 CTO TMR Associates, Inc
 Doing interesting things with small computers since 1979

-
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[Index of Archives]     [Linux RAID Wiki]     [ATA RAID]     [Linux SCSI Target Infrastructure]     [Linux Block]     [Linux IDE]     [Linux SCSI]     [Linux Hams]     [Device Mapper]     [Device Mapper Cryptographics]     [Kernel]     [Linux Admin]     [Linux Net]     [GFS]     [RPM]     [git]     [Yosemite Forum]


  Powered by Linux