Shredding times
The following tables show the standard required times for shredding without host I/O, listed by drive type. The same standard times also apply to shredding encrypted drives.
Since each volume is overwritten three times with dummy data by default, Volume Shredder requires three times the time listed in the table below. If you want to change the default settings, use the formula shown above to calculate the time required.
For DKxxx-JxxxSS/KxxxSS/HxxxSS disk drives
|
Rotation per minute |
RAID level |
Standard required time* |
|
|---|---|---|---|
|
15 Krpm |
RAID 1 |
2D+2D |
85 minutes |
|
RAID 5 |
3D+1P |
65 minutes |
|
|
7D+1P |
30 minutes |
||
|
RAID 6 |
6D+2P |
35 minutes |
|
|
14D+2P |
20 minutes |
||
|
10 Krpm |
RAID 1 |
2D+2D |
110 minutes |
|
RAID 5 |
3D+1P |
70 minutes |
|
|
7D+1P |
35 minutes |
||
|
RAID 6 |
6D+2P |
35 minutes |
|
|
14D+2P |
20 minutes |
||
|
7.2Krpm |
RAID 1 |
2D+2D |
185 minutes |
|
RAID 5 |
3D+1P |
120 minutes |
|
|
7D+1P |
50 minutes |
||
|
RAID 6 |
6D+2P |
65 minutes |
|
|
14D+2P |
25 minutes |
||
|
*Data drive capacity is assumed to be 1 TB. |
|||
For flash drives (SSDs)
|
Number of parity groups |
RAID level |
Standard required time* |
|
|---|---|---|---|
|
From 1 to 4 |
RAID 1 |
2D+2D |
30 minutes |
|
RAID 5 |
3D+1P |
20 minutes |
|
|
7D+1P |
15 minutes |
||
|
RAID 6 |
6D+2P |
15 minutes |
|
|
14D+2P |
10 minutes |
||
|
*Flash drive capacity is assumed to be 1 TB. |
|||
For FMDs
|
Number of parity groups |
RAID level |
Standard required time* |
|
|---|---|---|---|
|
From 1 to 4 |
RAID 1 |
2D+2D |
20 minutes |
|
RAID 5 |
3D+1P |
10 minutes |
|
|
7D+1P |
10 minutes |
||
|
RAID 6 |
6D+2P |
10 minutes |
|
|
14D+2P |
5 minutes |
||
|
*FMD capacity is assumed to be 1 TB. |
|||
When host I/Os are performed, the required shredding time is at least six times that of when no host I/Os are performed. If a DKxxx-HxxxSS data drive is used for creating a parity group on an encrypted data drive, the time required for shredding that parity group is the maximum time listed.
If the volumes to be shredded belong to drives of mixed types or mixed configurations, the longest required times associated with the drive type or drive configuration apply to all volumes. Thus, mixed types and configurations take more time for the volumes to become available for use than when the drive type and drive configuration are the same. When you add drives or change drive configurations, you should arrange the drives into those with the same standard required times, and then add drives starting with those volume types requiring the least shredding time.