IGT Part 2: SAN Misers

This article is part of a series on Incoming Google Traffic (IGT).

This next group of keywords are due to an unfortunate design problem with Microsoft SCVMM and Hyper-V:  ISO images are copied from the image library to individual VM directories on SAN storage before connecting.

“share image file instead of copying it”

mount iso scvmm

scvmm does not support shared dvd iso images

virtualization platform on host does not support shared dvd iso images

From the look of it, many Hyper-V/SCVMM admins out there are a little disappointed with this ISO file proliferation.  Disk space is cheap, right?  Well, it’s not that cheap.  Especially not on a SAN.

At several gigabytes for each ISO, this method is not for those with meager storage budgets.  And if merely copying was not bad enough, keep in mind that you always have to leave room for an image file in case you need it later.  With one VM per LUN, that amounts to quite a bit of wasted storage because deleting the duplicate ISOs when not in use does not necessarily free up any usable storage.

I covered this topic in a more lighthearted way back in October and Gabes Virtual World has a current article that discusses Hyper-V storage requirements.  The latter emphasizes how one VM per LUN greatly inflates storage requirements when considering space for snapshots.  Two problems, same cause.  By the way, VirtualCenter and ESX allow admins to simply mount multiple virtual machines to a single shared ISO file.  It happens instantly and does not consume nearly as much space.

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