On Wed, 2 Jan 2002 00:32, Jason Lim wrote: > > It's called RAID-1. > > I dunno... whenever I think of "RAID" I always think of live mirrors that > operate constantly and not a "once in a while" mirror operation just to > perform a backup (when talking about RAID-1). Am I mistaken in this > thinking?
RAID is generally configured for always being active, but there's lots of things you can do with software RAID, that's the advantage of software products in an open-source OS, you can make it do whatever you want. > From what you have said, basically the only advantage to the Arcoide > products are that they reduce load on the system, as they can perform the > RAID-1 mirror process in the background idependent of the OS. RAID-1 mirroring isn't that intensive. Compare the amount of resources required for copying the fastest available hard drives (that can sustain 40MB/s) to the power of a 1.4GHz Athlon CPU... > An alternative spin on what you have said (nearly identical) would be to > put double the hard disks in each server (eg. a server has 2 hds, put in 2 > "backup" hds). Configure them in RAID-1 mode, marking the 2 backups as a > spare, and then "adding" them to the RAID array every day via cron. This > would cause the 2 live HDs to be mirrored to the backups, and then > disengage the 2 "backup" HDs so they aren't constantly synced. That sounds excessive. Why not have three drives configured in a RAID-1 setup and then add a drive and remove it as soon as it's re-synced (so it's a three-drive RAID-1 with only two drives active most of the time). -- http://www.coker.com.au/bonnie++/ Bonnie++ hard drive benchmark http://www.coker.com.au/postal/ Postal SMTP/POP benchmark http://www.coker.com.au/projects.html Projects I am working on http://www.coker.com.au/~russell/ My home page