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I am trying to build a backup server which will make ... backups... :) Since I have never built a server like this what would you say should I look for?

Components I have been looking at:

  • Intel E2220
  • Enermax Modu82+ 425 Watt
  • 2x Corsair 1 GB DDR2 Ram at 533

I still need a Motherboard and some good drives.. I would like to get 3 TB of space.

Hope you guys can help. I have looked at the Asus P5Q VM because it has 6 SATA ports and a built in grafics card and 6 500 GB Drives by Western Digital 5002ABYS RE3

What are things I should look for? I am not planing on putting the backup server in raid though.

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up vote 1 down vote accepted

I'm going to assume from your mention of 3TB storage that you're looking at backup-to-disk. This is essentially just "dumb storage", so the box really needs to be powerful enough to run your OS and backup tool(s) of choice, and nothing more. Bearing that in mind, the factors you need to consider are getting the data from source to destination (and back again) as quickly as possible, and ensuring that your backup is still going to be there for you when the time comes that you need it.

So we're looking at minimum gig ethernet and - yes - RAID. Storage is so cheap these days that I seriously believe there is NO excuse for skimping on RAID, and in fact I would say that RAID 10 is now the RAID level of choice for most scenarios. Edit: per Oskar's comment, you don't need RAID 10 for this however, go RAID 5 or 6 and it will do the job (see Oskar's own post for further info here). (End edit). You don't want to be in a situation where one of those disks fails and you lose some data that you need to get back, do you?

If budget allows I would also include a tape unit. I like tape; it's robust, cheap, high capacity, portable, and will provide you with a second line of defence in case the server lets you down. Make it an external one so that you can connect it to another box if the worst does happen.

Working from there you're looking at a scenario where you do a full backup each weekend (making certain to backup everything, not just what you think you need), daily differentials, and also run the last full off to tape as your second line. So figure how much data you have, how much of it changes, how many weeks you want to keep, and calculate your storage requirements from that. Double the result because storage used is going to grow, and I think you'll be doing good.

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I'd say go RAID5 with a hot spare, or RAID6 - as it would be better for redundancy because if the wrong two disks break down in RAID10, the data is lost. – Oskar Duveborn Aug 4 '09 at 19:15
Good point; disk perf isn't that critical, reliability is where it's at. Editing my post to reflect this. – Le Comte du Merde-fou Aug 4 '09 at 19:24
I disagree Oskar - if ANY 2 disks break down in RAID 5 the data is lost, whereas in RAID10 at least if 2 different disks break you still have all the data along with the benefit of a much faster rebuild time. If the 2 that break happen to be mirrors of each other than yes you will lose the data anyway. That being said - I'd recommend a RAID5 config with backup to tape of the RAID5. – August Aug 4 '09 at 19:53
True August, I didn't think that through enough - if using a hot spare, RAID10 would be safer due to faster rebuild and the fact that you have have a 67% chance to survive a second disk failure during it. If not using a hot spare, RAID10 would be safer as well - though in both cases it would give you less space. I'd prefer RAID6 in any case for backup. – Oskar Duveborn Aug 4 '09 at 20:26
I'm gonna stick with RAID 5 or 6 in my answer anyway; despite what I said about storage being cheap, there's still no point in spending money that you don't have to spend. For an app or file server though it would still be RAID 10. – Le Comte du Merde-fou Aug 4 '09 at 20:38

3TB of space, I'd say get 4 or 5 1TB drives and build a RAID5 with optional (highly recommended) hot spare (or go RAID6). As 1TB drives are as close to twice the price of 500GB drives you can get - there's little use going for 500GB drives in my opinion.

Get a separate (or if possible two) smaller drives for running the OS, would be best to run those in a mirror/RAID1.

You do not want to loose data and every disk WILL break sooner or later. The question is when...

...doing RAID5 is normally easy within the OS itself - no need for a card.

Lastly, if you're going to protect company data no matter how small the company is - you do not want to build the machine yourself. Buy a preconfigured server by a big-name manufacturer instead like Dell or HP.

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+1 for pre-configged; safe and boring is the way to go with backups every time (and I really DO mean that). – Le Comte du Merde-fou Aug 4 '09 at 19:23
1TB drives are actually cheaper now ($ per GB) than 500GB drives. e.g. here in australia, seagate 500GB are $69 while seagate 1TB are $115. $1 AUD is currently approx $0.84USD. – cas Aug 4 '09 at 22:11
Yeah I've noticed that drive price too here in Sweden - I thought that was just a fluke or some short 1TB drive campaign. Cool to know it's that way in other countries as well! – Oskar Duveborn Aug 5 '09 at 10:10

I'd go with a pre-integrated server for backups. Something with support. Unless I was only backing up my personal stuff at home. You don't want to have anybody looking at you a little sideways when they get to figuring out there's something gone wrong with the backups and how it might have been your integration.

If you're going to build your own: Mirror the OS/Applicaion drives. RAID 5 the volumes you're using for backups, preferably with a nice hot spare.

Don't totally dismiss tape, as an option for your long term data storage needs. If you're doing quarterly, year end, or month end backups. Also it's way easier to get tape off site than disks. Backups aren't good backups if they can be destroyed in the same incident that destroys the originals. So contemplate the placement of your backup server closely. Will a single lightening strike, spilled coffee, contractor with a carpet steamer (yeah it happened to me) destroy the server, and the backup server? If yes, then you should think about if that is good enough backup.

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one thing that i think is essential for a backup machine like this (especially if you're not going to have a tape drive, which would be a really bad decision IMO) is to have hot-swap bays for the drives.

this would allow you to quickly swap drives if any die (essential if you use RAID).

it would also allow you to upgrade the drives easily as larger drives become affordable - e.g. a quick and easy upgrade to 2TB drives.

and finally it would allow you to use disk drives in a similar fashion to tapes - as "data cartridges" that can be installed in the machine, written to, and removed to place in a safe or off-site. you'd be trading off the extra fragility of hard disks versus the cost of a tape-backup drive (external LTO-4 drives start from around $1500 AUD - which would buy a LOT of 1TB drives)

oh, and look for a motherboard with 8 sata ports rather than 6. 2 for the operating system drives (RAID-1 mirror), and 6 for the data drives whether they're in RAID or not. 8 is quite common these days (at least on AMD chipset boards which i'm more familiar with than intel boards)

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