Do not buy Promise Technology Inc products.
They’re no good. Really, if you try to use one of their products — in particular something like their Vtrak M500i iSCSI RAID units — you will wind up being somewhere between dismayed and enraged.
Here’s my story, which I hope is not typical. My company owns one of the aforementioned iSCSI RAID devices. It has 15x500 GB SATA drives in it, two of which are online spares; the other 13 are assembled into a single large disk array. The disk array contains — sorry, that should be “contained” — six RAID5 logical disks, which are then made available to our servers using, you know, iSCSI.
The Vtrak has two redundent power supplies, which is kind of nice, and they (like the disks) are supposedly hot-swappable. One of the power supplies on ours is a little flaky; it has from time to time shut itself off. A simple turn-off and turn-on of that power supply has corrected the situation in the past, and seemed like a good enough solution until we got around to getting a new power supply unit.
I was very careful to use the past tense there. Yesterday, the power supply flaked out again. I turned it off, and for some reason — my esteemed boss hypothesizes a botched interrupt handler in the firmware — the unit decided that what had really happened is that I yanked disks 3 and 4 out of the unit altogether. Hilarity ensued, as you might predict if you get how RAID5 works.
It’s now 34 hours later and we hope to be narrowing in on the end of our series of filesystem repairs pretty soon. It might be done sometime tonight! Who knows, maybe all our data will still be there! Except for the one logical disk that the unit forgot about in the meantime.
I hear that you can get a similar unit from Dell, a rebranded EMC device, for not all that much money; and I can practically guarantee that you’ll be happier in the long run if you do.
(If I had a real blog or a LJ account or something like that, this would be there and this space would have contained a funny cartoon or video clip or something. Sorry about that.)
