Should I do Disk or Tape backup

[Colin_Moloney]

Our office hours are 7-4 and IT staff doesn't stay past those times. We currently have one LTO-2 drive, but our current backup needs exceed 700GB of storage. AutoLoader LT0-2 drives seem to be in the price range of $5000 which seems a bit expensive. Would we be better off backing up to external USB 2.0 drives every night. I could plug in a few drives and no longer have the need to swap tapes or purchase expensive hardware. We would take a couple external drives off location every night.

What are other people doing that have backup needs of 800GB of storage.

[charles_meetze]

it would be insane to only use disk. those can be fried by surge or just plain old drive failure. pretty much gotta invest in tape library. even then your problem of moving that much data overnight without fiberchannel or some other high speed network could be iffy. i hope we can go to SAN and have backup to disk AND tape. at least that is what i dream about...
:)

[Colin_Moloney]

These backups are being performed through a gigabit switch so time isn't that much of an issue. We just want to avoid investing $6k in a new tape autoloader. Thought spending $3k on external disks may be a better investment. Then we could take home a couple external drives every night. Yes, drives do break but not very often and what's the chance a drive craps out the same day we need to do a restore?

Guess we'll just have to buck up and buy an autoloader. Thanks, and any other feedback would be greatly appreciated.

[charles_meetze]

someone once told me 'what are the odds of 2 drives failing in a RAID 5?" well, one night about 2 am guess what happened? on a critical server too. after that i don't trust anything...:)
go with a good tape library and good warranty at least.

[Richard_Kokoszk]

Do you have to do a full backup each night?
A full backup for us is 790 GB, so we got a drive array & do a full to it every end-of-week, then during the week, do incrementals. Every couple weeks we do a archive job & send that tape out.

[Colin_Moloney]

No, we don't have to do a full backup every night. Are you suggesting we backup to a disk Array and then every other week we move the backup to tape. My concern with that is we could lose almost two weeks of data if there is a building fire or something catastrophic. Maybe I'm just being paranoid but just want to make sure my backups are being done the best way possible without costing the company an arm and a leg.

Are you using some type of network attached storage to make your backups to and if so that sounds like it could be a bit spendy as well.

[Richard_Kokoszk]

As our servers are at a secure facility, we don't have to worry to much about much happening. But I see your point.
Maybe this way - do a Friday full backup. On Monday, change the tape & do weekly incremental's. Then Friday change the tape and do another full. The only problem is - how big are your incremental's?

[Colin_Moloney]

Not sure how big the incrementals are because I've always been doing a full backup everyday. I know this sounds silly but it's less about how much time it takes backup to run and more about how to get all data to one tape since I don't have an autoloader and I obviously can't get a full backup to one tape.
I guess by using the full backups on Friday strategy I would only have one day of too much data for one tape. Maybe I would need to go in Saturday mornings to pop in a new tape. The incrementals should fit on one tape I assume.

[Richard_Kokoszk]

For incrementals, you have to try one & see. Our incrementals are ~.25 of the full, so that means that you may have to use more than 1 tape for the weekly incrementals - and leave room for expansion, as you may have a exceptionally busy day. You may need to use more than 1 tape for the week's incrementals, but you won't know until you do one.

[Ken_Putnam]

I haven't priced drives lately, but rather than getting a library, you could get a second tape drive (same type, as similar as possible) and setup a "cascaded drive pool" When the first tape fills up, the job will continue on the second.