keithy1959 wrote:I feel your pain - I have just spent £3000 of my company's money on a 10TB iScsi box, configured it all up to 2TB Volumes, and am now stripping it all back to 1.5TB "Drives".
In fairness to BackupAssist, at least in the stuff in the UK's vendor, it does make it clear that there is a 2TB limitation, but I read that to be a limitation of BUA ( and Microsofts) to back up FROM >2TB, not TO partitions >2TB. Caveat emptor.
This is another issue than the thread starter is talking about. Windows Image Backup is using VHD files to store the backed up data. This format was originally invented for a product called Virtual PC yonks ago and has two limitations among others:
- It cannot grow bigger than 2TB
- It only supports 512 byte sector size (please note that the sector size has nothing to do with the cluster size of a partition! the sector size is used internally by the harddisk and usually cannot be changed)
If you have a source partition
that is larger than 2TB and want to back it up using Windows Imaging, then the first limitation kicks in. The workaround is as simple as annoying: If you plan to back up a partition with the Windows Imaging technology, then don't make it bigger than about 1,5TB (so you have some space left for snapshots).
However if the target drive
is not using a sector size of 512 byte, and the manufacturer of the drive does not offer a way to change the sector size, then the second limitation becomes a problem and you cannot use this drive for Windows Image Backup.
After much digging I found thishttp://social.technet.microsoft.com/wik ... -list.aspx
Hope it's of use and helps people avoid the situation I've found myself in. Don't take the list as gospel though, there is at least one case in the thread below where someone has purchased an HP external drive because it was on the list and it didn't work for them.
The problem with external harddisks is that most vendors don't guarantee or even tell you which harddrive models they put into their enclosures. My recommendation is to buy the harddisk separately, so you know exactly what you get.
I also spoke to Hitachi again this afternoon and the chap said the drives I have support 512e. I used CrystalDiskInfo to discover that the drive inside housing is a Deskstar 7K3000(HDS723030ALA64) and the spec sheet says it has a sector size of 512. There is no mention of whether or not it's 512e of native 512b (must be 512e since it's 3TB) despite the very important impact on compatibilityhttp://www.hitachigst.com/tech/techlib. ... 000_ds.pdf
That's not completely true. Drives that are larger than 2TB and are using 512 byte sector size work perfectly fine, they just cannot be partitioned with a MBR partition table. However when using GPT that is not a problem, and there are actually >2TB harddisks that use 512 byte sector size. For example this is some data of a Hitachi Deskstar SATA 3TB 5K3000 (model # HDS5C3030ALA630 ):
- Code: Select all
> fsutil fsinfo ntfsinfo h: | findstr sector
Bytes per sector: 512
Bytes per physical sector: 512
Of course this drive works with Windows Imaging. In general if you see a >2TB drive that has a giant warning on it "doesn't work with Windows XP", then this is a good sign, and a hint that this drive may use sectors with 512 bytes.
davenicholls wrote:BackupAssist on Server 2012 "PREPARED" it as NTFS with not option to choose GPT. That's fine for this 2TB drive but if it was a 3TB, 4, 6 or 10TB drive (the future is always bigger...) then clearly GPT will be required and BackupAssist need to offer the choice of GPT or NTFS when preparing drives for use.
GPT is a partition style and NTFS is a file system. They work on different layers, so your drive is using GPT and
While I have not yet tried Windows Server 2012 Beta, I'm pretty sure that the drive was automatically partitioned using GPT.