Backups

[eek]

This is probably a pointless question but it would be useful if someone doublechecked my logic and can point out any flaws.

I'm currently backing up all important data from the computers around the house to an Unraid server (if you don't know it, its a variation of raid with a single parity disk that will cope with a single disk failure. If I get multiple disk failure I will loss data but unlike most raid solutions you can still access all the data on any drives that haven't failed. This should cover failure of any computer hard disk and a single disk on the unraid server.

To improve on this I'm planning to run rsync to create a copy of any really important data in a few direrctories onto a second disk on the unraid server (the windows home server approach). After doing this means that unless I strike really unlucky and both disks die I should be covered.

So all I have left to worry about is total failure (fire, flooding....). Does anyone have any ideas of what the best current solution is for remote backups.

[daniel_owen_uk]

DVD left at families house?

Seriously how much data do you have that is 100% critical? Do you work from home?

[Saracen]

You have to put "best" solution in terms of the cost, and put that in terms of the value of the data at risk. There are industrial strength solutions but they cost a lot, or "domestic" solutions, but they have limitations, such as speed of transfer, and perhaps your broadband connection being a single point of failure.

As always, it's a case how how far you'll go, and how much money you'll spend, to address the marginal element of risk after you've implemented the previous bit.

It also somewhat depends on the nature of the data. If a large percentage of it is permanent, like a photo or video archive, you may want a different solution to that where you have 100 data entry operators constantly updating orders.

If it's a "house" system, then you may beed to go no further than :-

- main copy on live PCs
- second copy on your server
- third copy on second drive on server, perhaps not part of raid
- fourth copy on DVD, at a relatives home or even in your in a fireproof safe.

If you have those four copies, what level of risk is there that all of them will get compromised at once? Of course, it does mean you have to keep to a routine of updating the DVDs, and until you do, any updated data after the last DVD copy only has three levels of protection, and if it's a server hardware failure, it could take out both the RAID copies at once ....or a fire could take out all three.

I think there's too many variables, not least budget, to give much specific advice about the "best" solution ..... unless you want a best-regardless-of-cost" option.

[benjus]

My Dad uses Carbonite to keep his business documents backed up (he works from home). It seems to work pretty unobtrusively but I don't think he's ever tested the restore.

You probably need to specify the amount of data you're talking about and how you see the backup being run (i.e. from the server itself or from a client application running on the desktops) to get more comprehensive answers.

It's important to remember that RAID is not, and was never designed to be, a backup system. It's designed to reduce downtime when a hard disk fails and/or improve disk performance. In that respect, you are right to be looking for an offsite backup system.

[Phage]

Are you after a cloud-based solution like Drop Box ?

[peterb]

I did start replying to this, then was distracted, so Saracen has pretty much made the points I was going to!

However, I would add that RAID is not in itself a backup solution. You still have a single point of failure in the raid card, and anything that causes corrupt data to be written will write it to the RAID, and if the RAID signature on the array becomes corrupted (admittedly, very unlikely) you risk losing the data.

If you are on a tight buf=dget, then you only really 'need' to backup up data that cannot be recreated. Original photos, music (that you wrote/played) or documents that you created. Everything else can be re-created from the source.

You may consider using USB sticks/Compact Flash or similar - or for larger volumes, solid state discs might be a solution.

Backing up to a non-raid hard drive is possible - storing that off site - but being a mechanical device, it will fail at some point. There are also internet solutions - there are companies that will store stuff for you - if you don'y mind your data being out of your immediate control - and you trust them.

Tape solutions are still cheap in terms of cost per byte, but with an LTO drive costing £500 upwards, and add in about £200 for a high end SCSI card, the initial investment is high. But the tapes are small and portable, and ideal for offsite storage or in a suitable fire safe (add from £250 upwards for a fire rated safe for magnetic media).

Do a riskassessment, decide what you have to back up (against what you must back-up, factor in how much time you are prepared to doing the backup, and how quickly you need to restore, and then deciide on some solutions.

[eek]

I did start replying to this, then was distracted, so Saracen has pretty much made the points I was going to!

However, I would add that RAID is not in itself a backup solution. You still have a single point of failure in the raid card, and anything that causes corrupt data to be written will write it to the RAID, and if the RAID signature on the array becomes corrupted (admittedly, very unlikely) you risk losing the data.


Do a riskassessment, decide what you have to back up (against what you must back-up, factor in how much time you are prepared to doing the backup, and how quickly you need to restore, and then deciide on some solutions.

The first thing to remember here is that I'm not using RAID but something called unRAID (see http://www.lime-technology.com/joomla/ ). This has the advantage of leaving the data disks as readable data disks provided I can find a machine that can read the reiferfs file system.

Before I started looking into this I saw enough scare stories regarding Raid or Drobo solutions to scare me from that approach and the windows home server approach (of making multiple copies of important files) seemed a bit basic.

I think the bit that I'm concerned about is how to store about 10-20 gb of data somewhere where it can be automatically updated fairly regularly. DVDs are fine for photos that I know what change and I want to keep but I know myself well enough to know that I would end up doing it once or twice and then forgetting to update it again.

Some I'm probable looking at a two tier approach:-

dvd's for photos updated once in a while
and something in the cloud for data I've not backed up onto dvd which needs to be cheap
cheap (ish)
runs on linux as unRAID is based on slackware.
easy to replace if the provider disappears.

Anyone think of anything better or similar to s3sync and amazon S3?

Cheers,

Ben