Discovering Sparse Bundle Disk Images

I was thinking about this a couple of months ago for our Mac clients in our non-profit organization. We have 30 Mac workstations with network shares on Windows Servers through SMB connections--our server admins refuse to turn on AFP or Macintosh services. Sometimes they upload files to a directory on the Windows server, but then receive messages that they don't have the proper privileges to move or delete the files while on the network share.

How well would it work to have a sparseimage bundle file formatted HFS Extended on the SMB network share where they could mount the disk, add their files, and then eject it. Also the Windows server is backed up nightly as their local drives are not. (Their workflow is to copy off the server, work locally from local home folders, and upload.)

Joe's article mentioned that VMWare stores a monolithic image file. This is no longer the case.

When creating a new VM or a new virtual disk, you have the option of splitting the disk into 2 GB chunks. (It's under the Advanced Disk Options disclosure triangle) While this isn't the tiny, easily backed up, files of a sparse disk bundle, it's a fair sight better than a single 100 GB file. (I imagine that performance considerations mandate a larger file size.)

In my experience, fairly few of these disk chunks change during my daily usage of Windows Vista in VMWare. I use it heavily, and there are usually two chunks that change most frequently.

I also moved my temp and cache directories to a second drive image, which I do not back up at all. I can always re-create it if need.

-- Nik

nikinik.net | http://inik.net | http://notions.inik.net

I read with interest your article on sparse bundles, and although I don't consider myself an expert, I was wondering if the new type of iPhoto library (used in iPhoto v.7) would be considered a "sparse bundle"? I know that they refer to it as a "package", and it seems to meet the same criteria you describe in your article. However, if I view the package contents of one of my many iPhoto libraries (I use iPhoto Library Manager to create various libraries, restricting each to a maximum size of 4.5gb) I do not see the "bands" that you refer to. I simply see the typical iphoto library contents, composed of files and folders for the various items that iPhoto requires. My question is, is a package always a smart bundle, or vise a versa? My iPhoto library packages do not appear to contain "bands", rather they contain the typical file folder setup traditionally associated with an iPhoto library, which makes me wonder if that is simply the way the package is displayed by the finder.

Additionally, the fine program Chronosync, from Econ Technologies contains a feature, "dissect packages" which allows incremental backups of these new iphoto libraries without having to copy the entire package which also makes me think that the packages are smart bundles. It sounds like iPhoto is already using a storage system similar to what you are describing in your article. Thank you for taking the time to read my comment.

[No, it's not the same, because in the iPhoto Library package, you have individual files that correspond directly to the images and other support files, rather than band files. Plus, you can't mount the iPhoto Library package as a disk. So there are similarities, but they're not the same. -Adam]

Regards,

Tom B.

In "Discovering Sparse Bundle Disk Images," Joe Kissell said "You can create and modify disk image files ... with the command-line tool diskutil if you're so inclined." I'm pretty sure he meant the "hdiutil" command-line tool.

So, Joe, does Apple's Backup 3 application support the sparsebundle format? I used to use Backup 3 to back up encrypted confidential financial records to dot-Mac using a sparseimage, but it quickly used up too much space.

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Bill Cheeseman - billcheeseman.name Quechee Software, Quechee, Vermont, USA www.quecheesoftware.com

PreFab Software - www.prefabsoftware.com