For 100GB of data:

Cost of a properly run data backup operation, using DLT’s as the backup media

Background:

  • There are 2 major tape formats – DLT (Digital Linear Tape) and DDS (Digital Data Storage);
  • DDS can store 20GB of data, and DLT can store 40GB of data.
  • Best practice is that each DLT/DDS is only reliable for read purposes within the first 4 writes;
  • DLT’s have over 50% failure rate if re-written more than 5 times; and
  • Based on bulk purchasing, each DLT costs around A$50 and each DDS costs around A$20.

References:

  • DLT http://en.wikipedia.org/wiki/Digital_Linear_Tape
  • DDS http://en.wikipedia.org/wiki/Digital_Data_Storage
  • Pricing for DLT http://www.tape4backup.com/93256.php
  • Pricing for DDS http://www.supermediastore.com/ibm

Backup Cycles in a proper data operation:

  • 31 daily tape groups – minus 5 weekly tape groups
  • 5 weekly tape groups;
  • 13 monthly tape groups;
  • 2 yearly tape groups.

Using DLT, which is more common. Number of Tapes in total per year is 417:

  • Daily 26 (days) x 3 (for 100GB) x 12 (months) / 3 (4 uses per tape before disposal) = 312 DLTs
  • Weekly 5 (weeks, 4 in current month 1 in previous month) x 3 (for 100GB) x 12 / 3 = 60 DLTs
  • Monthly 13 (months, 12 in current year, 1 in previous year) x 3 (for 100GB) x 1 (set for year) = 39 DLTs
  • Yearly 2 (years, 1 for current year, 1 for previous year) x 3 (for 100GB) x 1 (set for year) = 6 DLTs

Total cost of running DLT’s for 100GB of data is $20,850.00 per year

Note: This is for the DLT media alone, does not include DLT tape backup unit, plus operators etc.

Contrast this with Data Vault Security.

100GB costs $3.21 per month per GB(100 x $3.21 x 12) = $3,852.00 per year

What happens to the costs when the amount of data to be backed up grows to 130GB?

The number of DLT’s per cycle (Daily/Weekly/Monthly/Yearly) grows to 4. Therefore:

  • Daily 26 (days) x 4 (for 130GB) x 12 (months) / 3 (4 uses per tape before disposal) = 416 DLTs
  • Weekly 5 (weeks, 4 in current month 1 in previous month) x 4 (for 130GB) x 12 / 3 = 80 DLTs
  • Monthly 13 (months, 12 in current year, 1 in previous year) x 4 (for 130GB) x 1 (set for year) = 42 DLTs
  • Yearly 2 (years, 1 for current year, 1 for previous year) x 4 (for 130GB) x 1 (set for year) = 8 DLTs

Total cost of running DLTs for 130GB of data is $27,300.00 per year, because DLT usage has grown to 546.

Contrast this with Data Vault Security.

130GB costs $3.21 per month per GB (130 x $3.21 x 12) = $5,007.60 per year

For further details and to set up your FREE test account, please contact Bradley C Hughes at DataBackupSecure.com, your international Data Vault Security Representative

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