PC Backup options

Ground rules: 6-10 PCs running a mixture of Windows/95 and Windows/98, with upto 8 Gbytes disk storage per machine.  None of the machines have SCSI disk drives or SCSI controllers so either a parallel port (printer port) or an IDE or ATAPI connection is required.  Security is handled by the physical security of the office.  There is no computer expert on staff so any solution must be operationally simple and convenient.  Unattended backup overnight is acceptable.  It is not necessary to fully backup every machine every day, but it should be possible to incrementally backup every machine daily, with periodic full backups.  The need for offsite storage of backup media should be discussed.

Initial investigation: I rejected Iomega zip drives and Jazz drives and also Sony LS-120 super floppies because they are too small.  The biggest drive in this category has a capacity of 1 Gbyte which means it would take 8 steps to backup a hard drive; also recovery would be slower.  DLT tapes, with a capacity of 40 GBytes/tape, were rejected because the cartridges are too big and the drives (~$1500) are too expensive.


Travan tape 4 mm (DAT) 8 mm
Comes in 5, 8 and 14 GBytes/tape capacity (HP), 8 and 20 GBytes (Seagate) 24 Gbyte (HP DDS-3)  (C1555B)
24 Gbyte (Sony DDS3 PCBACKER 9000)
Exabyte Eliant 820 (14 Gbyte)

The rationale behind the difference in pricing for the drives and the media between the Travan technology and the DAT technology has to do with the tape tensioning mechanism.  The DAT system puts the tape tensioning in the drive, so the drive is more expensive; and the mechanism has to be beefier because if it breaks, you've lost the drive.  The Travan technology puts the tape tensioner in the cartridge.  It is more lightweight, because if it breaks, you've lost just the cartridge which is no big deal.
Or so they say - I am cynical.  In most businesses, drives are capital and media are expensed and it is typically easier to spend expense dollars than capital dollars.  I'm just a dumb engineer, but in my mind, every dollar you spend is a dollar of lost profit.

For more information, see the manufacturers and vendors websites:

HP:  http://www.hp.com/tape/colorado/DesktopProductsSpecifications.html  (Colorado Travan tapes)
HP Colorado Travan 5 Gbyte drive: P/N=C4354B    $178 @ Egghead    Media P/N=C4425D $284/10 @ Computer Stop
HP Colorado Travan 8 Gbyte drive: P/N= C4389B   $319 @ Computer Stop     Media P/N=C4429D    $  323/10 @ Egghead
HP Colorado Travan 8 Gbyte drive is $238 @ Egghead, almost a third less than Computer Stop.
HP Colorado Travan 14 Gbyte drive is     $287 @ Egghead       Media P/N= C4436D  $165.21/5 @ Egghead

All of the following require a SCSI interface controller
An AHA2940 SCSI controller is about $196 @ Shoplet, a mail order house.
HP DDS3 24 Gbyte DAT drive  $1139 @ Computer Stop  Media is $21.90 @Egghead
HP DDS2 8GB Bare Internal drive  $749.95  @ Computer Stop Media is $7.80 @ Egghead

Seagate:   http://www.seagate.com/cda/tape/guide/0,1253,,00.shtml
Seagate 20 Gbyte Travan drive: STT220000A-RFT
Seagate 8 Gbyte travan drive STT28000A-RFT

Seagate Scorpion 8 Gbyte DAT drive $649 @ Computer Stop  Media is $7.80 @ Egghead

Sony DDS3 PCBACKER 9000 INT 24GB DAT  drive:  $903.95 or $858 @ Egghead.

Ditto Max 7 Gbyte cartridges $34.00 @ Shoplet http://www.shoplet.com/hardware/db/386511.html

Exabyte is the only manufacturer of 8 mm tape drives, everybody else OEMs from them.
Eliant 820  MSRP $1,580
Mammoth LT  MRSP $1,617

Cautions and caveats:

There are no standards for backup media formats as there are for MS-DOS format floppy disks; so once you buy into a backup solution, you are married to it for a long time.  HP has some backwards compatibility in that a 14 GByte travan drive can read a tape written on a 5 or 8 GByte drive; but not a Seagate 8 Gbyte drive.
The capacities quoted assume that compression occurs.  Compression is statistically justifiable, which means that most times it works and some times it doesn't.  Most financial data I have seen is very inefficiently encoded, which means it will compress well.  However, your results may vary and it is not easy to predict compression performance.

Think about offsite storage of backups.

Think about virus scanning.  Remember, you must continually update your signature files.