Notes on DAT tape drives
We have had very positive experience with DDS DAT tape drives, and can recommend them for their reliability.
- Advantages:
- blank tapes are cheap
- the tape drive unit is quiet
- tapes do not require retensioning
- most (if not all) DAT drives feature hardware compression
- Disadvantages:
- the tape drive units are more expensive than Travan
At our offices, we use a Seagate DDS-3 DAT drive which has served us well.
Effectiveness of hardware compression
Our independent tests have shown that on average, you can expect a 1.4:1 or 1.5:1 compression ratio when backing up a file server (including system files).
Thus, you can expect the following tape capacities:
- DDS-2: 4 gig native, approximately 6 gig compressed
- DDS-3: 12 gig native, approximately 18 gig compressed
- DDS-4: 20 gig native, approximately 30 gig compressed
Compression ratios will vary depending on the type of data.