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I know that Windows 2008 R2 and 2012 were limited to 2TB volumes (or at least the size of files) due to the fact that internally Windows Server Backup uses VHD files which are limited to ~2TB.

I can't find anything in the docs from MS regarding 2012 R2 and whether internally WSB uses VHDX instead, bumping the limit up to 64TB. We're looking to backup a few volumes with ~4TB per volume. I'd hate to have to go and reallocate them just to get backups working.

MS has to know that people have backup needs for volumes larger than 2TB, right?

atmarx
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  • [YES.](http://upload.wikimedia.org/wikipedia/commons/6/68/Yes_logo.svg) – the-wabbit Jan 09 '14 at 21:53
  • My bad -- I didn't exactly leave the post with a real question. I should have ended it as "Does Server 2012 / 2012 R2 still use VHD internally for backups, or has Microsoft moved to VHDX?" – atmarx Jan 09 '14 at 21:59
  • If you break it up in two questions, then: [No.](http://upload.wikimedia.org/wikipedia/commons/8/8d/No-Symbol.svg) [Yes.](http://upload.wikimedia.org/wikipedia/commons/f/fb/Yes_check.svg) – the-wabbit Jan 10 '14 at 08:08

2 Answers2

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Hm. ANother one bites the dust....

I know that Windows 2008 R2 and 2012 were limited to 2TB volumes

They were not. Only for MBR discs. Not for GPT diss.

See also:

http://support.microsoft.com/kb/2581408

Pretty much every company these days likely has larger paritions. 2tb are not relaly large when you get larger discs. But then, the problem really in your case is more what you think you know - not the facts.

Change to GPT partitions and there you are.

TomTom
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    Andrew was referring to the limitation in the .vhd virtual disk format, which, in fact, [*is* 2 TB](http://en.wikipedia.org/wiki/VHD_(file_format)#Limitations). Since *Windows Server Backup* has been using .vhd files as backup destinations, it was subject to this limit. In Server 2012 the Server Backup [uses `.vhdx`](http://workinghardinit.wordpress.com/2012/08/13/windows-server-backup-benefits-from-improvements-in-windows-server-2012/), the new limit is 64 TB. – the-wabbit Jan 09 '14 at 21:51
  • Thanks syneticon-dj. TomTom, I'm aware of MBR vs GPT. In fact, the only way I have volumes larger than 2TB is by initializing the disk as GPT. As syneticon-dj noted, WSB was limited to the VHD size of 2TB, regardless of the disk's partitioning scheme. I didn't realize the change was made in 2012 -- for some reason, I thought I was still running into that issue using 2012. – atmarx Jan 09 '14 at 21:56
  • That may not be an issue though - you could split a backup on multiple VHD theoretically. THat said, seriously, I expect many companies having larger data to simply use a more mature backup product ;) – TomTom Jan 09 '14 at 22:05
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    @TomTom 4 TB is not what counts as "larger data" anymore. It is commodity. And a small business "CEO" with 2 underpaid employees and a $500 "server" under his desk certainly would think really hard before purchasing software which requires a separately licensed backup agent for every imaginable application type. But as I noted, it has been addressed already. – the-wabbit Jan 10 '14 at 08:04
  • But 2008 R2 is also not a current operationg system anymore. THat makes your argument circular. Especially given that your CEO is much more likely to make backups by making copies to a USB disc in the real world. – TomTom Jan 10 '14 at 08:27
  • I spoke with a few backup companies, and all of the backups that are rely on VSS are subject to the same limitations as WSB. Since that's changed in newer OSes, it should be much less of an issue. Once you hit 64TB though, it looks like partitioning the data is the only option left (or moving to a dedicated storage SAN that doesn't rely on Windows for replication / backups). – atmarx Jan 30 '14 at 00:45
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I have trouble finding authoritative references either, this blog post claims:

The VHDX format allows for 64TB. That means your Windows Server backup can now handle more than 2TB LUNs. This should be adequate

It should be easy enough to verify by just doing a WSB run on a Windows Server 2012 (R2) host and looking at the result.

the-wabbit
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  • as an aside: as tempting as it seems to do backups to an NTFS-compressed destination, it would need some work to actually succeed. NTFS compression is [FUBAR for large files](http://serverfault.com/a/554119/76595) by default. – the-wabbit Jan 10 '14 at 08:24
  • agreed. i rarely use it, although i'm planning to start using deduplication much more heavily going forward for new file servers since 2012 R2 seems to be more robust. – atmarx Jan 11 '14 at 02:41
  • This doesn't appear to be the case. Windows Server 2016 Datacenter edition, 22TB and 63TB volumes on GPT partitions with 16384 bytes per cluster, vss working without issue, and I get a message saying `Volumes larger than 16777216 megabytes cannot be protected` – Cookie Monster Sep 24 '19 at 18:03