IT Zone guide to data storage.

Colin,

You highlighted that the company needs to 'archive' it's data once it's completed a project and storing on to a disk is not safe enough. You are correct.

please email me at anthony at depositit.com as we have an archive solution which allows you to store the information in encrypted format securely on 3 servers in 3 separate data centres.

This is MUCH safer than tape or disk storage as there is no fear of corruption, no worry about the media becoming compromised or damaged. No fear that when you need to view the data that the hardware is no longer available or of course that the location you are storing the disk is not burgled, burnt or flooded! You can retrieve the data at any time directly off our servers.

Backing up to tape or disk is better than not doing anything but it's certainly not the safest method.

RAID is often mis-understood, not helped by the salespeople who sell it also not understanding what it is / does / how it works.

Adding in a second, third, forth, or sixth drive does not make your computers more reliable. It makes them LESS reliable in that they are more likely to go wrong (more hard disks to fail).

What RAID does is increase fault tolerance, i.e. when they do go wrong more often, it's even more likely that they won't destroy all of your valuable data in the process.

Specific things that RAID doesn't protect you against include:

(a) user accidently deletes a critical file
(b) the server crashes / fails in a way which corrupts your data (e.g. power failure).
(c) the RAID controller itself fails and scribbles all over each drive (and yes, I've seen that one!)
(d) Other human intervention e.g. accidently rebuilding the wrong array / replacing the incorrect drive / etc causing spectacular loss of data

Furthermore, the added complexity of RAID systems can make system recovery slower when things really have gone belly up!

Of course, that's not to say RAID isn't essential, it's just to set the expectation level of people buying the technology...

Stewart Twynham
stewart@bawden-quinn.co.uk

The amount this company is spending on CD/DVD media means that you actually have a bit of cash to play with.

Upgrade the tape drive in the server to an Ultrium2/LTO drive so that it can take 200/400 GB per tape (Tapes cost less than £30).

Organise data on the server in Monthly Folders and decide how many months you need to keep live (ie on the server ready for easy access).

When a new month starts, copy the oldest month to LTO tape, and then do this again to create a second copy. Delete this month from the server to free up space.

Keep one LTO tape onsite for easy retrieval of old data, and send the other to an offsite tape storage company for long-term security - eg www.backuptapestorage.com.

The amount of time and money they'll save on CD/DVD media costs will pay for the above solution to be implemented.

When I bought a computer system in 1999 there was a choice of back up systems.

Panasonic LS-120 (MB) super floppy
Iomega Zip discs 100MB or 250MB
Floppy discs 1.44MB
CD-Writer CD-R / CD-RW discs

On a cost per MB basis the CD-writer route was chosen - as I knew no-one with LS-120 or Iomega drives these were ruled out on compatability grounds - they were hugeley expensive per MB too.

Nowadays added to the list of options are external HDDs, DVD+RW, DVD-RW, DVD+R, DVD-R and DVDR9 formats plus the 8.5GB DVD DL discs (too expensive per MB). Plus the flash drives, but too expensive as a long term solution.

By this time next year there will be Blu-Ray and DVD-HD discs / writers - removable media with a promised upto 50GB capacity (dual layer versions).

Use of CD-RW discs helped impress the ethos of never only have a single back up disc - at least two are required. Optical media like CD and DVD is so easily corrupted and not reliable for use a the sole means of back up.

In fact currently each file I create has 6 copies - One on the internal HDD, one on a DVD-RW (internal DVD writer), one on a DVD-RW (external writer), then a copy on each of three USB-2 linked external HDDs.

Desktop shortcuts to each of the 5 back up methods ensure easy drag & drop backing up.

With regard to external HDDs if you have an Apple OS you'll have the advatange of faster backing up, using Firewire 800 if the external HDD supports it - Windows XP currently is half-speed Firewire 400 (practically same speed as USB2 niominally 480 speed). Windows new Vista
OS (next year - 2007) should catch up with Apple and offer Firewire 800.

What is your recommendation for storing Terabytes of media on a weekly basis -

Problem - Approx 400 CD's, each with btwn 400-600 Meg data.
Approx 80 DVD's each with 3 - 4 Gig data.
Back Up x 45 each with 3-5 Gig data.
1 server with DLT back up.

The nature of the business (design and litho printing) is these disks have to be readilly available for use and are normally kept within close promimity of work stations.
Problem is once a design job is complete, it is copied to disk (now mainly DVD), data is removed from server, their is usually one copy of disk, disks can get corrupted, if they incurred a disaster / theft ...

Can you suggest options for storage and retrieval - budget is restricted, I can justify ROI but they don't have piles of cash!