Wednesday, October 29, 2008

Quick review of Integrity VM 4.0

I've been a user of IVM since 3.0, and I'm about to finish putting in production a fairly big server that will host a bunch of VMs.

One of the big drawbacks of versions prior to 3.5 was the lack of a built-in MPIO. You had to either purchase the expensive SecurePath, or use PVLinks which forced you to use the LV backend. I used PVLinks, but the concept of having to manage VGs both inside my VMs, and one level upwards on the host, was complex. I wouldn't suggest it to anyone who is not familiar with LVM. On the upside, using VGs on the host can prevent mistakes since PVs are harder to corrupt than raw disks.

Furthermore, to benefit from network redundancy, APA had to be purchased seperately, which also increased costs. So of course the big advantage of 4.0 is the 11iv3 host, that lets you use its built-in MPIO. Furthermore, the VSE-OE now includes APA for free (It was about time). So these two items are covered. And did I say that APA was now very easy to configure? I'm not fond of the System Management Homepage, but the APA configuration in it is now dead easy, and quick. Only a linkloop feature is missing.

The agile addressing still seems weird to me, it's not as simple as usingSecurePath, but I'm catching on slowly. Actually finding the LUN of a device is a hard task, I'll have to rewrite for 11iv3 for this matter.

ESX administrators are used to managing files. They're easy to move around, and you can "see" them, which prevents mistakes. It's a similar paradigm as a DBA preferring files to raw devices. In this area, there is one improvement: AVIO is now supported with a file datastore. Even with a tuned VxFS, I found the files datastore to be slow when I did tests with 3.0 last year, you can be sure I'll try again this time.


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