Endpoint Backup space requirements

[robert]

Let's say I wanted to backup 10 Windows 7 systems 1 per week and retain the last 4 copies.

All Windows 7 systems are identical (service pack level, patch level) and the disk size is 40 GB of which 30 GB is used.

How do I calculate the required disk space for this? The assumption is that I would be using an existing Veeam 8 repository.

[Vitaliy S.]

Do you plan to backup the entire image, volumes or just folders/files?

[robert]

I was planning on an image-backup so as to be able to restore the complete system in case of a disaster.

[Dima P.]

It’s hard to predict since there might be some data with low compression/deduplication ratio, but based on my raw OS backup tests, I can say, its usually a half of the actual size. For instance, clear Win7 install (its somewhere around 20 Gb) backup was about 9-10 gigs and my workstation system volume (~100 Gb) backup is 45 gigs

[robert]

So 15 GB (half of what's used on the disk) times 10 -> 150 GB for the initial backup of all machines. And how much for the additional backups (4 retention points)? The same or less?

[Vitaliy S.]

Incremental points should be the same, meaning that half of the actual changes (as Dima says).

[robert]

Let's assume that there are few changes per week (maybe 10%?) 10% of 15 GB would make 1.5. Times 10 (Number of PC's) would be 15 GB. 4 retention points: 4 x 15 GB = 60 GB.

So for 10 PC's 150 GB (initial) and 60 GB (changes) for 4 retention points = 210 GB. I know the numbes are hypothetical but I'm trying to understand the logic.

[Vitaliy S.]

Yes, that's correct.