Saturday, January 29, 2011

Does the WINNT folder need to be backed up?

I just recently transferred to the IT Department in my company and one of the tasks on my plate is to review their backup strategy and make sure it's "good". Although I have a lot of IT experience with previous employers, I've never really been involved with backup and restore much beyond the theory level.

They are performing nightly backups to a 400GB tape and a 1TB USB hard drive. The hard drive is backing up absolutely everything on all five servers. The tape is backing up just the essential stuff: web sites, databases, exchange, departmental shares, users' home folders. Both jobs start at 11:00 PM. The tape finishes around 8:30 AM; the hard drive finishes in the middle of the afternoon.

The selection lists were set up by a third-party company. The IT Manager is questioning whether it is really necessary to back up absolutely everything; for example, do we need to back up the WINNT folder? If a server dies, is the tape backup sufficient to bring it back to life, or do we need more?

    1. Backing all servers up to a single consumer disk seems a bit silly to me, these things are seriously cheap these days, if you have to use that method at least buy one per server - it'll mean you can backup quicker and the loss of one disk doesn't affect the other servers.
    2. If you can make sure that you are using a backup method that lets you backup and restore EVERYTHING (including winnt directory) in such a way that you can VERY quickly recover your entire server ASAP. Having to reinstall the OS, then the apps, then the config and data is never fun when people are breathing down your neck and it also can't be certain to work.
    3. Do you rehearse restorations? if not how do you know they'll work when you need them?
    4. Presumably your business would be hit badly by the loss of one or more of these servers? if so then get your IT manager to budget for a backup system that WORKS, there are too many people going around with their fingers crossed on this matter, it doesn't have to cost the earth but will require putting some time into the project at the start and periodically testing your backup tech and processes - otherwise you might as well not be there.
    Jim B : I agree that you should at least have 2 disks- 1 per server seems like overkill
    Chopper3 : 1TB disks cost £50/$50!
    Farseeker : 1Tb for $50?? Which wonderful land of green jelly is that? They're still $250+ where I am for an external
    Chopper3 : These (http://www.dabs.com/products/seagate-1tb-expansion-usb-3-5--5K36.html?refs=47210000&q=1tb) are £62 retail, I can get them for £50-£55 - I may not have done the £/$ rate properly though :)
    From Chopper3
  • The IT Manager is questioning whether it is really necessary to back up absolutely everything; for example, do we need to back up the WINNT folder?

    Backups are not about having a copy somewhere else but being able to restore what's needed in case it's lost. You would only need to back up an operating system's files if you needed to restore that OS. It's certainly possible to only back up your data and plan on rebuilding the server as long as you are willing to accept the time required to rebuild the system and you have a way of keeping track of what patches you have put on the server so you can rebuild it at that point in time. In addition you have to accept the risk that any applications that are installed may have issues when being rebuilt. Once you've tried a restore this way you'll know if this approach can be successful for you

    If a server dies, is the tape backup sufficient to bring it back to life, or do we need more?

    By your admission that the tapes only have "essential" data (which is in quotes because to me the essential data is what's required to make the service work- not just user data) your tapes do not contain what's required to rebuild a server.

    There are several questions on serverfault about backup strategies but in a nutshell, you need to figure out what your time to recover the entire service is and work backwards from there before you can get meaningful answers to this question

    From Jim B

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