On 7/11/2013 8:17 PM, Henrique de Moraes Holschuh wrote: > Anyway, I will make a summary that actually separates the apples from the > oranges, because we were clearly talking about different things:
No, we are talking about the exact same things. > 1. If you're buying enterprise RAID arrays, you should have matching disks > and firmware, and they must be in the vendor approved list. Best to get > them all from the same vendor. This is also true of quality PCIe RAID HBAs. LSI and Adaptec both publish compatibility lists for not only certified drives, but also storage enclosures, etc. Other RAID card vendors may do so as well, but the list is small as so many companies OEM LSI's cards. I'd never buy a Highpoint nor Areca so I can't tell you about those. IMHO they're junk. > 2. If you're buying HBAs and disks to build software RAID arrays, a mixed > disk farm is a good idea. In theory anyway. The sticking point here is how to select drives for use with RAID HBAs, which was the entire focus of my previous message. I've already made that case. Now, one may plug an odd assortment of drives into an LSI RAID card and have it work. But that's more the exception than the norm. Go to an LSI training event or call their support team. They'll tell you exactly what I've stated here: All drives in a given array should match-- make model, and firmware. Is this an absolute requirement? No. But it's what you do if you want to avoid many potential headaches that mismatched drives can cause. I presented this information because the OP expressed a desire to purchase a real RAID card, specifically an LSI. I presented the information to help him avoid potential problems. > PS: I'd appreciate if you could list some of the HW RAID cards that are > doing disk blacklisting, that's something nice to know so that I avoid > buying one of them used for the home. I've seen HW RAID cards mark the HDD > as "failed" in the on-disk metadata and you would have to take special > action to be able to add them back into an array... but actually > blacklisting failed disks in NVRAM is news to me. I'm not going to spend my time researching and compiling a list of current RAID cards, if any, that do this. The information I presented is to educate the OP so he can avoid pitfalls. I've come across RAID cards in the past that exhibited this behavior so it was worth mentioning as a caveat. With some you could manually remove a serial number from the EEPROM/flash blacklist if you jumped through enough hoops. I ran across at least one enterprise RAID HBA some time back that wouldn't let you modify the list. It's not just enterprise fibre channel arrays that are picky with drives. Even entry level quality RAID HBAs can be as well. With LSI's RAID HBAs (models with cache DRAM) the core portion of the firmware that will cause problems with mismatched drives is common to all their RAID cards, from entry through enterprise, $300 to $1200 USD. Even if the OP selected 4 different drives from the LSI compat list he may still encounter problems due to different firmware behavior. -- Stan -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/51df6339.2030...@hardwarefreak.com
