Large raid 5 storage needed.

[chavo]

Hi all,

My company have asked me to look in to getting all our archives PDF'd and backed up. by law they need to be kept for 20 years.

With this in mind i think we will probably have about 1terrabyte of PDFs, and we will need fault tollerance. RAID 5 is the most effective as it gives us the most space for our money but i dont know what to buy!

If anyone can give me any pointers as to what to go for i would be in your debt!

Steve.

[directhex]

if this is serious, then you need to go WAY beyond the realms of "desktop" RAID (i.e. a commodity server with a RAID controller and a bunch of disks).

you should really be looking at "real" vendors - EMC, Pillar, NetApp, and those like them. Prices will start at around £160k for 10TB - but that'll give you more redundancy than you can possibly imagine.

talk to a storage reseller, they'll be able to point you in the right direction

[chavo]

Thats a little bit OTT! 160k to the director i told him £1000! i was looking at the likes of Raid 1 (mirror) but you use effectively double the storage space! and for that i would rather have an array of 3 disks inside a caddy running Raid 5. will pay around the 1k mark.

[kungpo]

Does the data need to be online? You could burn them to HD or BD R media and store somewhere safe? I presume this is to save space from all the paper?

Otherwise a cheap NAS like a Terastation will give you a cheap 1.2 tb NAS you could use (although i would still archive off to to Optical or Tape media.

[Fraz]

Ultimate Storage Limited - MirrorDrive I RAID

+ 2* 1TB disks?

Pretty cheap and cheerful though, but it'd work.

If it's for proper archiving, I'd use tape.

[directhex]

repeat after me:

raid is not a backup solution

raid is not a backup solution

raid is not a backup solution

raid is not a backup solution

[Fraz]

I agree. Do you want something to put the files on for daily usage, and a backup as well? If so, raid + tape.

[Splash]

If you're looking at something for a legal requirement then 1k of hardware for a 1Tb solution just ain't cutting it. A RAID array is good for redundancy in case of disk failure, but what do you do if there's a fire in the building that destroys the server with the array in where do you stand from a legal standpoint? Will what is effectively "the dog ate my homework" stand up in court as a reason not to produce said documents?

You need a full backup and storage strategy involving at the very least offsite storage of some sort. As for your Director he has two options really - do it on the cheap or do it properly. £1k falls distinctly into the former category.

[Lucio]

Personally, I'd invest in a tape drive and a large quantity of tapes. Our Quantum DLT v4 drive plus 5 160GB (320GB with compression) cost about £1000.

Alternatively if someone pipes up that magnetic storage doesn't last more than X years, Blu-ray recorder and a lot of double-layered 50GB discs.

I'd also check your requirements, as last I checked, tax records and the like need to be kept for 7 years.

[Fraz]

Alternatively if someone pipes up that magnetic storage doesn't last more than X years, Blu-ray recorder and a lot of double-layered 50GB discs.

I'd trust magnetic storage over Blu-ray disks any day.

Tapes - proven backup solution used by everyone sane.

[arthurleung]

1K you can get 4x1TB drives in 2 2-Bay NASes

RAID1 on both of them, and copy the same data to both of them (double backup + redunduncy)

RAID itself is not a backup, just a method of protecting against physical failure. Backup + RAID = Secure

[Lourdes]

You can go with a cheap setup for online access, just make sure you're backing it up to tape. I'd build a small server with 3-4 750-1000GB drives using Linux s/w RAID5 + hot spare or RAID6 and a tape drive for backups (store them on and off site).

As Splash says you need a proper backup strategy, that's most important. RAID != backup, I've said goodbye to many a corrupt array.

[directhex]

1K you can get 4x1TB drives in 2 2-Bay NASes

RAID1 on both of them, and copy the same data to both of them (double backup + redunduncy)

RAID itself is not a backup, just a method of protecting against physical failure. Backup + RAID = Secure

if it's not off-site, it's not secure

[Funkstar]

if it's not off-site, it's not secure

Quoted for truth

This is something I need to bring up with our management as well.

[chavo]

Thanks for all that great info there guys, sadly the data needs to be easily accessable as we still use it from time to time. The information in question is legal documents in relation to conveyance.

I suppose we could archive the hard copies of site and have the 2tb nas drive on site... thats the best form of security as paper never goes out of fashion!

We store all the new data on an FTP site from our host but this is expensive for large amounts of data so is out of the question really. i think a nas drive is really the only option but if it corrupts the last thing we want to do is start rescanning so raid one for its fault tolerance is good. I think i am just going to have to go with that for now.

thanks for all this info.

[Fraz]

Seriously, it's bonkers to go to scanning a huge pile of paper and trusting it to a single nas box - even if it has got raid.

You should definitely make an off-site backup of the NAS of some sort - even if it's just getting someone to burn a shedload of DVDs. It'll save you untold amounts of money rescanning all your paperwork, if e.g.:

Some pikey steals your NAS box.
Building burns down.
A second drive fails during rebuild.

And believe me, that last one isn't as unlikely as you'd think. It takes a long long time to rebuild a terabyte disk if it's also serving files at the same time.