Recently I had to create a budget backup system that would still have the performance and flexibility we needed. The requirements are pretty major: current backups growing quickly, soon to be upto 2-300 gigabytes. Backup must be fairly easy, so an admin assistant can run them. System must be able to grow, and support increasingly large amounts of data. And it must be cheap to run and maintain.

We'd been using firewire external drives for backup with good success, but once we hit about 100+ gigabytes on the backups the firewire drive enclosures began to get write failures. I talked to a tech from CRU, who also make an external firewire enclosure, and he said this is a known problem with firewire drives, they forget where they are at some point, even when you are using the oxford chipsets. This is what we experienced too, unlreliable writes once data grew beyond 120 gigabytes or so in the backup.

I decided to once again try removable hard drive trays, I went with the Dataport V plus from CRU. These are very high quality units, made from aluminum. If you try this with cheap hard drive trays don't complain when it stops working. All CRU hardware comes with a 10 year warranty.



Because we will be hot swapping the drives, we also needed to get a hot swapping supporting controller card. I'd recommend using SATA all the way, because I already had the parts I used the Promise Ultra 133 TX2 IDE controller card. If I would have been able to find one, I would have used the single port 3WARE raid controller card, the 7000 series, but I couldn't get on in time. However, the Promise controller card works fine, except for a problem installing the drivers.

Because we are using very large hard drives, 300 gigabytes, I also had to update Windows 2000 to support drives over 137 gigabytes. This is a simple registry edit. Links and directions to upgrade Windows 2000 and XP to support hard drives > 137 GB here

Important: make sure all your backup drives are the same size, from the same company, and ideally from the same batch

Failure to do this may result in problems in the future.

Please note, your motherboard also needs to support large drives, > 137 GB, most modern ones do, the controller cards also need to support it, all new ones do, including the promise we used.

Setup and configuration
Install the controller card after upgrading Windows to support > 137 GB hard drives. Make sure driver is correctly installed.

Install the CRU dataport hard drive bay.

Connect to controller card.

Install the hard drive into the tray.

Now you're ready to go. First you'll have to set the hard drive to fool windows. For the first time, turn off computer, while off turn on removable tray with key. Boot up, Windows will recognize the drive. Format the drive using NTFS [if it's a window box, linux use your favorite file system of course]. Set the drive letter to be a unique letter, that won't be changed by additions. I make it something like v:\

Once formatted, right click on drive in windows explorer, uncheck the 'Allow indexing service to index this drive to allow for faster...'

This will be important when you use two drives, it will allow you to read either correctly even though they are hotswapped

If you are using more than one drive, you will need to format it and give it the same drive letter as the first one.

Once the drives are formatted and have been assigned the same drive letter, you're ready to go.

We'll be using device manager to mount and unmount the drives in the hot swapping configuration, this is a very important step, if you skip this you could lose data, and possibly the hard disk partition tables, which requires a full reformatting.

Assuming you want to start a backup, place the hard drive tray into the bay. Turn on the key, wait for drive to power up. Go to device manager [that's control panel -> system -> hardware -> device manager -> disk drives. Locate your disk drive. It should say 'scsi drive' or something like that. To mount the drive, right click on the correct drive, select 'enable'. In a few seconds the screen should jump, and the drive is now mounted in Windows.

Run the backup, we use windows native backup utility. Once the backup is done, you'll want to unmount then stop the drive. To unmount it, go back to device manager, right click on the drive, and select 'disable'. Warning: do not select 'uninstall'. Disable and enable are windows equivalents to 'mount' and 'unmount' in the unix type world. Once you have successfully disabled the drive, you can turn off the drive tray key, which turns off power to the drive, then you can remove it once the drive has spun down safely.

That's all there is to it. A very economical solution for very large backup requirements, you can add as many trays and hard drives as you need, which makes this pretty much open ended in terms of future data requirements.

Failure to follow these steps and hardware requirements carefully, trying to save a few dollars, could result in full on failure, don't complain if you didn't buy CRU equipment, or got a cheap no name controller card.

This method solves one of the main problems with using removable hard disk trays, Windows not recognizing the contents of each new drive. Turning off disk indexing on each drive unit, and manually stopping and starting the drive using the 'device manager' disk enabling/disabling feature solves this problem. You will be able to read each drives contents as you hot swap them. And they said it couldn't be done....
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Sounds like an interesting setup, one question: Why didn't you use a SCSI / Tapedrive?
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Mostly because of two issues:
Cost
Capacity

You can make a very large capacity Tape Storage system, but the largest tape cartridges currently available are about 100 GigaBytes, though they claim to be 250 but that's assuming almost 3 to 1 compression. Almost all the data we are backing up is graphics and audio, which doesn't compress very much in backups.

However, for those so inclined, a SCSI backup system would work, it's just a lot more expensive.

For example: LSI Logic LSIU160 PCI to Ultra160 Single Channel SCSI host Adapter Card. This is the cheapest part, about $30 from new newegg.com.
Sony AIT-3 Model SDX-700CE Tape drive: [100 GigByte tape, 250 Gigabytes standard data, compressed]$2200-2300 depending if it's external or internal. Cartridges run about $60 each. So backing up 2-300 gigabytes of graphical/audio/video type data would require 2 to 3 cartridges, which defeats the purpose of a simple, easy to implement backup proceedure, this would require tape swapping during the backup. Multiple tape units are available, but the cost of course skyrockets.

Plus of course there's the question of actually accessing the tape data, say you lose one file and need to replace it, with a hard drive backup, you run the restore utility, index your backup media, the hard drive in this case, then find the file and restore it. It's a very fast process, since you are accessing a very fast medium, hard disks. With tape the whole tape has to physically wind or rewind to the point the data is at, then you get it. Not fast.

Tape is an excellent solution for large organizations with large IT budgets, or where it's absolutely imperative that no data loss happens [hard drives can and do fail, but then again, tapes can and do break]. But the odds are probably higher that your hard drive gets corrupted. We run two backups to avoid this potential issue, that way there is always at least one reasonably upto date backup no matter what happens.
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