So, I'm planning to migrate the storage in my server to something with a bit more fault-tolerance. I want to do at least RAID 5 with a bunch of 2TB Samsung F4s. Budget is roughly £100 or so. I've been looking at the following: RocketRAID 640 RocketRAID 2640 RocketRAID 2680 I realise that these probably aren't full-blown enterprise-grade RAID cards, but do they provide some degree of processing offloading from the CPU? What are the primary differences between them? Additionally, I'd like to start off with RAID 1 with 2x 2TB drives, and then buy a third 2TB drive later on. Would it then be possible to convert the RAID 1 set to a RAID 5 set without having to wipe the first two drives? Later on, can I add more drives to the RAID 5 set and have its capacity expand? Finally (and most importantly), will I be able to boot Windows Server x64 from the 4TB+ array on a non-EFI computer?
£100 is very unlikely to buy you any sort of on-card processing. While I do think it's a good idea to have hardware RAID 5 over software RAID 5, if you're not prepared to spend around the £180 or more, then it's IMO better to buy nothing, or to wait 'till you can afford the card. My advice, save for an Areca! I've got a 2320 and tbh it's a bit pish. It's some weird "partial hardware" card but it's not perfect. That's £220 or so these days, but imo its overpriced now. Don't get a cheap card though, just don't. While online capacity expansion (OCE) is perfectly possible (I do that myself every time I expand, stick more disks in, tell the controller to expand the RAID, job done) - migration between RAID types is more tricky. The short answer is it'll be card dependent. But definitely do not count on it - I would be surprised if you found a card that could do RAID 1 -> 5 migration on a three drive basis. If it's not boasted about in the feature set, the card won't do it. Finally, from what I've read the answer is no. Or kind of no at least. Microsoft have a tonne of info about EFI and other such related goodness on their site, worth looking into. But from what I can understand with a GUID partition table on a non-EFI mobo if you install an OS on it the OS has to have an NTFS MBR on the array in order to function. No EFI on the mobo means no booting from an EFI partition. I can't remember the exact limitations this entails although IIRC if you boot using that NTFS MBR you're effectively subject to NTFS and MBR limits, which means no logical disk larger than 2Tib's. Seriously though, you'd be bloody nuts to boot from your storage array. Unless you're needing to run proper server programs on the thing, there's no good reason to. It just makes everything much more complicated if you have problems with windows, or problems with the array. At least if windows is on some random disk then you can have problems with the array and still fix it from within the OS, or problems with the OS and not lose/have to mess with the array.
Looks like I'll save up for a proper hardware RAID card then - no point blowing £100 for software-RAID-on-a-card! The RocketRAIDs i mentioned above do have online capacity expansion and online RAID level migration, so I guess that's covered. I also just realised I have a spare 2.5-inch hard drive lying about, so my boot drive is sorted. Which brands are recommended for full hardware RAID? (I know you've already mentioned Areca).
As I understand it, and this is from memory and a little reading (not so much, because if I ever went full hardware raid it'd be Areca) the three best brands are Areca, 3ware, and LSI ain't bad either. Also, check with online RAID level migration that a two drive RAID 1 -> three drive RAID 5 migration is possible. I could easily migrate my RAID 5 to a RAID 6 by adding an extra drive, but that's because basically all that does is add an extra parity block (read: drive) to the array. All migrations are not made equal. edit: The man you really want for this stuff is "Mister_Tad" - a user here. I thought he'd gone off-radar but it seems from his profile that he at least still visits the forums. Most of what I know I've learned from him.
Right, I've done (a lot) of reading, and have narrowed it down to the following cards which are reasonably affordable (the Areca/3ware stuff is definitely out of my league): LSI MegaRAID 8704EM2 RocketRAID 4310 Both drives definitely support RAID 1 -> RAID 5 migration. The Highpoint is cheaper, and appears to be faster, but LSI is better known and apparently has the better software. I'm finding it quite tough to find performance and software reviews for these cards, particularly the LSI so I'm not sure what to choose.
if you're looking at that kind of price range then i'd highly recommend the lsi 9260 cards instead - the 4i being ish the same price as the 8704em2 if you buy the card & cable separately... Well, forgetting that it's a 6Gb/s card (of no use for HDDs naturally, but could allow you to re-purpose it for 6Gb/s SSDs 'if' you wanted to in the future), it also has a more powerful processor which will benefit R5 & 4x the onboard cache (+ using 800 rather than 667 DDR)...
Cheers for that demon, don't think I'll be raiding SSDs anytime this decade, but hey the price is the same! Currently stalking a very tempting 9260-8i on ebay atm
I have that LSI card in my server. It's fast and hasn't missed a beat. It can get hot when being hammered however.
jfyi, the 8i (& 16i & 8i/8e &...) has the same max specs... ...& providing you appreciate those limits re-total transfer speeds at any one time, it's perfectly possible to have one or more SSD arrays & one or more HDD arrays (as i do already). A very useful thing about them is that you can stick a 2nd one in & create arrays spanning across both cards which pushes a doubling of the total bandwidth... ...should you suddenly want to get above 5GB/s sequential reads & 3GB/s sequential writes. [NB the actual doubling gives ~5750MB/s & ~3700MB/s, but it's better to round down somewhat with expectations] ...the reason why i've hung onto the 4i i got cheap as it would allow a much faster 'proper' 6Gb/s SSD array (when they're available & money allows) + still having bandwidth for (at least) my 15K7 SAS drives. Oh & re the heat - other people have commented on the 9260s getting hot, but even with the battery add-on (restricting air flow) & a large card directly below then have had no issues at all in over a year of use.
From a quick search, isn't it only a low profile card (not sure what your 'server' is but these are for 2U rack-mounted cases)? Well, the vast majority of results are for a 9650SE-4LPML & this appears to be backed up by the official data sheet. Otherwise, imho it's a bit of a something & nothing card in that, whilst it obviously does have some processor or other, it's older & slower tech which also doesn't support SAS or 6Gb/s which 'may' limit its uses into the future... ...though obviously it is much cheaper.
I have the 2680 and although it's pretty quick (my array has write speeds sufficient to saturate gigE and read speads well over 200MB/s), I think I read somewhere that its not a proper hardware raid controller. It does support OAE, as I just added in the 6th drive a few weeks ago, and although it unsupriseingly took >15 hours, it managed to get the job done just fine. My only gripe, was it didn't come with SATA breakout cables and I had to grab some seperately off ebay.
Look at the specs of my server, it's obviously not rack-mounted and unlikely to use SAS drives Chances are that the LSI is going to spiral beyond my budget, so unless there are any deal-breaking issues with with the 3ware, I'm go nna get that.
Is the 3ware a new card? 3ware is a old company purchased by LSI. Dont get me wrong they make great cards. I use one 3ware and one LSI. Now, there is a bargin to be had, http://cgi.ebay.co.uk/AMCC-3Ware-95...Components_InterfaceCards&hash=item3a54d0cb1c it is a great card, had 128 cache (no BBU), has a very nice web interface and is cheap. I am one of the 276 that have bought this card, if you make an offer of £40.00 it will be auto accepted. Oh, it can be used on a regular PCI
^^ Yeah, no point in PCI tbh. There's also an LSI 8708EM2 going for around £140, might spring for that instead. The 3ware also doesn't do RAID 6, which seems rather strange..
The deal-breaking issue is that the 3ware 'appears' to be low profile only, so wouldn't physically fit in anything other than a 2U rackmount... ...so just saying to double-check that before buying if you're sure that you won't need a decent 6Gb/s raid solution.
