RAID 0 vs RAID 5

[dood]

Re: RAID 0 vs RAID 5

^
Good score, just hope the batt is good. There's a web based config and maintenance utility under windows which will fully test and charge the battery for you. Not sure how this is supported under linux.....but regardless, good deal!!

Just to add some more information to the thread... On many enterprise RAID controllers, if you don't have the battery installed, they won't even let you enable write caching.

Also, in my last batch of HP servers, I ordered them with a flash-backed cache card instead of battery-backed. I was surprised to find that they still had a plug-in module for the cache card, until I realized that it was just a small capacitor bank to take place of the battery.

Also, with the HP servers, if you don't install a cache module at all, your RAID options are 0, 1, and 5. You can only run 10 if you have the module installed. Of course, even if you're running 0, 1, or 5 anyway, the speed increase by adding a cache module is quite dramatic.

[ratdude747]

Re: RAID 0 vs RAID 5

Updates!

1. The card's bios let me test the battery... it returned an estimate of 255Hrs.

2. The drives came today... I ended up RAID 0'ing them and using a 4kb stripe size; I read that when commands aren't in queue, then smaller sizes are better. Correct?

[ratdude747]

Re: RAID 0 vs RAID 5

I forgot to upgrade the firmware and under load she croaked...

A firmware reload later... since I have to redo it anyway (I have a bad feelign there was some corruption involved)... I recreated the array using 256kb stripes (just to see if there is a performance difference).