- Cost of tapes
- Cost of tape drive
- Time to backup
- Time to restore
- Time to manage tape drive
- Tape backup software
As for a time to backup and time to restore standard, there again, mileage will vary. There are too many variables to consider starting with the type of data to back up or restore. For example: It is not rare to see restore performance as low as 100-200 KBps for a large file server. On the other hand, an equally large database could achieve restore performance above 30 or 40 MBps using the same hardware and backup software.
This leads to the next cost item on your list: the backup software. The same situation applies, as there are multiple software packages all ranging in price. Because most backup software products a priced per processor and not per GB or TB of data to back up, the price per GB will vary from one organization to another for the same amount of data.
The only glimpse of hope in your quest for information is the storage management cost. For example, a 2002 Meta Group study stated that "organizations that have formal storage policies/administrators manage 3.8TB per administrator, on average." A little math would provide an average data management cost per year. Unfortunately, this is a long way from any kind industry standard overall TCO for tape storage.
This was first published in November 2004