if you have 2 HDD on RAID-1
does the 2nd drive act as a backup?

http://www.linuxjournal.com/article.php?sid=5653

Originally posted by shraz
if you have 2 HDD on RAID-1
does the 2nd drive act as a backup?
yes

PSFServers-
Can you comment on why if a host is running RAID 1 it would take 7 hours to restore a server?
Thanks

Originally posted by sawbuck
PSFServers-
Can you comment on why if a host is running RAID 1 it would take 7 hours to restore a server?
Thanks

Perhaps it takes 7 hours to fsck the file system after a complete crash? I've heard that ext3 for Linux recovers much faster. UFS with soft updates should also recover quickly on FreeBSD, especially when using the background fsck.

The beauty of RAID 1 is that a hard drive crash is transparent... unless you're checking your server logs, you might not even notice.

sawbuck: Trying to not get off-thread here... If you are running RAID-1 in a hotswap config, you could just pull out the bad drive and plug in the new drive, and have it begin to rebuild. Rebuilding won't keep your server offline, so it's not particularly important that it happen immediately.

shraz: Back on track, I don't agree that RAID is a backup solution. Should a hacker access the server and damage any data on it, a RAID implementation will not help you at all. Where I work, we use RAID-5 (described in the article posted above for those unfamiliar with RAID setups), and -backup- to NAS and tapes. So should a hacker (note this isn't the only scenario, but a very possible one) create havok on a server, we can still go back to prior to when the hacker gained access to our server. Certainly we hope that will be a last resort, but sensitive data requires sensitive measures to handle it. And yes, I acknowledge that perhaps one of the hard things with this may be finding exactly when a hacker gained access to a server (as you don't want to restore to a point with good data, but a backdoor/security hole still allowing access to your server)--BUT we still have all of our data.

Just my $0.02,

Doug Mayer
Strike Solutions

<EDIT> Noted who each paragraph was directed to. ;)

thanks for your input
I was looking more for the HDD failing then hacked heh

Well for drive failure then RAID would be fine. But I would really caution against not using some form of true backup solution.

Originally posted by sawbuck
PSFServers-
Can you comment on why if a host is running RAID 1 it would take 7 hours to restore a server?
Thanks

I think you answered your own question. RAID 1 doesn't require a "restore" on a HD crash. The only thing I can think of is the server was pulled off line why the array was rebuilt, but there are controllers that will allow this to happen transperently in the background.