Re: Best way to duplicate HDs
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).
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