I support a non profit. They got an ML350 G5 donated to them and I immediately put it to good use for them 🙂 It came with four HP 300GB 15K SAS drives – and of course, they have all now failed. I have been replacing the drives and they are all 6Gb/s drives, but the HP controller in the ML350 is a 3Gb/s controller. I have a nice 8 port LSI MegaRAID SAS controller sitting here with battery backup and everything – can I just swap out the controllers and expect everything to work?
I haven't found much about the differences between 3 and 6 Gb/s SAS interface from a physical layer. As near as I can tell, it should work just fine. I'm just curious if anyone has any experience doing this.
I'm not hung up on the drives being hot swappable, so if not I may just see if I can physically alter the case, toss the HP drive cage and stuff a different cage or mounting system in there to accommodate the better controller with the newer drives.
Ugh – now I remember why I prefer white box servers for one-off or small business vs. the "big boys" like HP, Dell, etc…
And anyone have a good source for rails for this thing? The HP prices are ridiculous – I could build another server for what they want for rails!
Best Answer
That's a lot to address. I'd keep the existing Smart Array p400 controller in place for now, provided it has a working battery-backed cache unit. Otherwise, your LSI will work, but it's not ideal.
The on-disk RAID formats are different, so this means a full rebuild. You won't be able to preserve your data if you do what you're proposing.
As for 3G versus 6G, it does not make a difference unless you're dealing with SAS expanders or solid-state drives. You won't see any difference in performance in your case.
I tend to think that HP controllers run better in their servers. I'm also not a fan of LSI's management software (MegaCLI is awful). Using LSI HBA cards for other solutions makes sense, though. Your best bet in this case is to make sure you have an HP P400 controller with BBWC cache (here's why). If you don't have the cache, your path of least resistance is to obtain one.
That way, you can be sure that your backplane, alerts, LED indicators and integration with system monitoring all work properly.
As for rails, check: http://www.racksolutions.com/hp/racking-hp/ml350