HP XP Data Shredder Software - Manual (Page 94)

2. Where the number of shredding operations necessary to overwrite data in the target volume
with dummy data is N, it can be calculated using the following formula:
N (rounding up after the decimal point) = (Capacity-of-target-volume + User-capacity-for-data)
/ Capacity-of-target-volume
User capacity for data:
•
Example: When the capacity of a flash disk is 72GB, the user capacity for data is 72GB
x n
•
Example: When the capacity of a flash disk is 400GB, the user capacity for data is
400GB x n
A sample calculation of the number of shredding operations:
•
Sample configuration: Flash disk is 72GB, RAID configuration is 3D+1P, and LDEV is
100GB.
Calculate the number of shredding operations. (72 x 3+100) / 100 = 3.16.
Round up the value 3.16 to the nearest whole number, so dummy data writing must be
performed four times.
•
A sample calculation of data-deleting conforming to DoD5220.22-M (performing dummy
data overwriting four times).
Sample configuration: Flash disk is 72GB, RAID configuration is 3D+1P, and LDEV is
100GB
1. Calculate the number of shredding operations:
(72 x 3+100) / 100 = 3.16. Round up the value to the nearest whole number, so
dummy data-writing must be performed four times.
2. Define shredding settings
See “Defining the Shredding Settings” (page 89) to enter dummy data 00 in the text
box and add a row to the Format List (add rows for performing the shredding
operation four times to the Format List).
3. Delete the data in volume.
See “Deleting the Data in the Target Volume” (page 90) , and execute the shredding
operation.
4. Perform [2] and [3] using dummy data FF.
5. Perform [2] and [3] using dummy data 00.
94 Performing Virtual LVI/LUN and Volume Shredder Operations