27 replies to this topic

[gcoupe]

Oh, and I've tracked down where Microsoft claims that WHS 2011 also does single-instance storage; it's in the "Getting Started" document:

Windows Home Server 2011 automatically backs up your home computers to the home server and can help you easily restore the entire computer or an individual file or folder to a previous point in time. The Windows Home Server Backup solution uses an innovative method to back up only the data that has not already been backed up before. Even if you have several copies of the same data on different computers, the data is backed up only once on your home server, and your home server keeps track of what data was stored on each home computer on each day. Backups complete quickly and efficiently, and use less space on your home server.

Mind you, that document also contains several errors, so I'm almost inclined to take this with a pinch of salt.

[ikon]

Oh, and I've tracked down where Microsoft claims that WHS 2011 also does single-instance storage; it's in the "Getting Started" document:

Mind you, that document also contains several errors, so I'm almost inclined to take this with a pinch of salt.

That certainly describes single instance storage. And the statement is pretty emphatic about it too. Let's hope it is true. And thanks for tracking it down. Great job.

[countryfarmer23]

@ ittog - What you are seeing is the difference between a full and incremental/differential backup.

It's not that. My initial backup and current backups still don't equal the size of the data on the disks and the data that is backep up.

Edited by countryfarmer23, 17 January 2012 - 03:56 PM.

[countryfarmer23]

I do agree there documentation is poor. I can't find anything. Even on their site that says WHS 2011 documentation it brings up old documentation from V1. So are you all seeing that the total size of your data partition and the size of the server backup differ from what they "actually" are?


If they had a white paper on things like this as they did with the older WHS I might be able to answer my own question.

I'd like to prove to myself that these files are actually beig backed up even though the size differs.

[diehard]

Here's an other quote,

Single Instance Storage (SIS) – This file system filter driver transparently removes duplicate files from a volume to save space without impacting server performance. As duplicate files are detected the files are moved to a central store and replaced with a 4KB reparse point. The new version of SIS was written to use the mini-filter model. SIS supports 128 volumes on a single server and includes a full set of new Windows PowerShell cmdlets to control SIS. SIS is fantastic on a build server (I’ve seen > 70% storage savings) and useful on home/group/user folders (I usually see ~15% storage savings). SIS adds 2-3 milliseconds to the I/O read-path and it does not significantly impact the performance of a file-server. SIS works great on failover clusters too!

[ikon]

thanks for that diehard. Great to have confirmation that SIS is indeed in WHS2011.

[gcoupe]

Thanks for the quote, diehard. Can you please cite the source for completeness? Thanks.

[countryfarmer23]

So any idea on the size difference?