Target-Based Deduplication; Tb File Server Backup; Deduplication Ratio Impact - HP StorageWorks 12000 - Virtual Library System EVA Gateway Manual

Table 3 1 TB File Server Backup
1st daily full backup
1st daily incremental backup
2nd daily incremental backup
3rd daily incremental backup
4th daily incremental backup
5th daily incremental backup
2nd weekly full backup
3rd weekly full backup
...
25th weekly full backup
Total
Approximately 11:1 reduction in data stored
Table 4 is an example that may not reflect the savings that all environments achieve using deduplication.
As shown, deduplication ratios depend on the backup policy and on the percentage of change
between backups.
Table 4 Deduplication Ratio Impact
Daily
change rate
0.5%
1.0%
2.0%
*4 months = 5 daily + 17 weekly backups
See Performance

Target-based Deduplication

VLS and D2D deduplication is target-based; the process is running transparently inside the hardware.
This means that when the data is read (by copying to physical tape, restoring a backup, etc.), the
device rebuilds the data. The data that is read is identical to the data that was originally written (like
tape drive compression); there are no pointers in the read data.
22 Concepts
Data stored normally
500 GB
50 GB
50 GB
50 GB
50 GB
50 GB
500 GB
500 GB
500 GB
12,750 GB
Backup policy
Daily full and weekly full
4 months* 6 months
15:1 19:1
12:1 13:1
8:1 9:1
for additional information on optimizing your deduplication performance.
Data stored with deduplication
500 GB
5 GB
5 GB
5 GB
5 GB
5 GB
25 GB
25 GB
25 GB
1,125 GB
Daily incremental (10%) and weekly full
1 year 4 months*
25:1 12:1
16:1 10:1
9:1 7:1
6 months 1 year
16:1 23:1
11:1 15:1
7:1 9:1