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Our IT department backs our data up to an external harddrive. Do we not still have the same risk of data loss because we back up from 1 hdd to another hdd? Should we use a tape drive?

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"Do we not still have the same risk of data loss because we back up from 1 hdd to another hdd." If someone cuts off one of your hands, do you suddenly have zero hands? – ceejayoz Mar 3 '10 at 21:17
@ceejayoz, that depends on how many you had before one was cut off. :) – John Gardeniers Mar 3 '10 at 23:54

You shouldn't backup to a single external hard drive but not for the reason you said.

There's literally zero wrong with going from disk to disk, data on tapes generally lasts longer than on disks but we're talking years or decades not the timescale I imagine you're concerned with.

My concern is that it's a single hard drive you're backing up to, what happens if some data is corrupted or deleted and it takes a few days to spot? at that point you may not have a copy.

It's old-school but I'd use a grandfather/father/son scheme to a bunch of disks.

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+1. It is ridiculous how uch common sense went out of the IT departments with tapes. Where in the day of tapes it was normal to have multi generations of backups - today people are ok with ONE disc doing a backu. What if the system fails during making a new copy? Ouch. OTOH I remember my days at MS wherea customer was researchnig dbcorruption and found the exact day it happend - 6 months in the past. They had 18 months daily full backups... NICE ;) – TomTom Jan 23 '12 at 9:28

You should have an offsite backup solution if you really care about the data.

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Unfortunately the answer for you depends on your situation and scope of backup project. At my company we are quite large and backups are deemed crucial so we use a Netapp solution.

I would agree with you and shy away from a hard drive to hard drive backup though just over USB. I would consider having a backup server if possible and large storage space so that you can go as far back as needed.

One system a server admin I worked with used was an Apple Xserv RAID. Very easy to implement and not too costly. It scales nicely and since its Java based, can be managed by any OS. So OSX is not needed for the front end management.

As others say, offsite if possbile, but again it depends on your scope.

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You should be backing up, at least recent data, to RAIDed solution, if it's not going to an off-site location.

You can use other types of media for archive/long term data.

A lot depends on amount of data accumulation over time you have.

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Backups need to go offsite at some point, or at least to a separate fire zone; otherwise what happens if you lose the building?

I prefer tape to disk for a number of reasons: it's simple, easily transportable, long lasting, and extremely cheap per GB by comparison. It also answers the question of "how do you backup the backup server?" rather easily (if you're not doing this you don't have viable backups, by the way - what happens if you lose your backup server?) A lot of people have bad experiences with tape, but investing in a good library from a specialist manufacturer can solve all of that.

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Disks are fine, just don't expect them to last for ever.

Offsite! Several disks. Remember power supplies too.

At this point, disks are cheaper per GB than tape.

RAID keeps your data available, but it is no substitute for backups.

No one cares about backups, everyone cares about restores. Test your backups, make sure you know how to restore, and without the server that made them. Test every so often.

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