Hello everyone! Since this is my first post, I just want to say I'm a huge fan of Level1Techs and have been following Wendell since he was on Tek Syndicate.
Finally after all those times he said "hop on over to the forums" here I am, finally engaging in semi-social activity for once...
As the title implies, I'm looking for a RAID controller. I have a home server that I plan on upgrading soon, swapping out everything except for the boot SSD and the chassis. It needs to support 8x SATA III 6.0Gbps drives through a PCI-E 3.0 x8 or x16 interface, and I understand that's going to come in the form of 2x SAS connectors. I've gone on Newegg and Amazon, searched for RAID cards that support such, but I wanted to get some input from the community as to who's a good manufacturer these days and who to stay away from. I understand Avago purchased LSI some years ago, that's a name I've always known to be great but maybe that's changed. I'm looking for the best way to put 5x WD Gold 8TB drives in RAID. I've heard the term "RAID-Z" thrown around but my knowledge of RAID is basically knowing the fundamentals of RAID 0/1/5 and that's it. Is there something I should be looking at instead of RAID 5, such as whatever RAID-Z is? Is RAID-Z better? I've missed out on any progress since 2009 and I understand there's been some advances although I don't quite understand the pros & cons. I'd also like the retain the ability to add 3 more drives in the future making a total of 8 without creating a headache. I don't know about adding drives to a RAID 5 setup and if it requires a rebuild of the array but I assume it's plug & play - someone please inform me if I am incorrect!
All help is appreciated - I feel like newbie being out of touch for so many years but I've caught up to the consumer grade stuff last year when I built my two i7-6700K PCs however server tech is something I've been trying to catch up on but it's incredibly overwhelming. I'm hoping someone can simplify it for me so I can spend less time trying to sift through extraneous marketing rhetoric.
I'm in no way a RAID SME but watching a lot of Wendell I've become a little bit opinionated on RAID.
For me I shy away from hardware RAID which is what it sounds like your looking into initially.
RAID Z is in reference to ZFS which is a software RAID.
I'd butcher the differences, the pros and cons of both, I'd say go watch some of Wendell's earlier stuff on RAID to grow an opinion on what you feel is best for your application. Why I went software RAID (ZFS) on my setup is that I felt its simply better- it can identify if and where corruption is, protect against bit rot and using FreeNAS I have a GUI to manage things vs. a BIOS setup for a hardware RAID. I first tried BTRFS at RAID5 but IMO it wasn't ready for prime time, I lost everything (had a backup so no biggy, I knew I was trying something new) but I've read the latest Linux kernel update improved BTRFS RAID 5 and 6.
Anyhow, lots of info out there on RAID, software vs. hardware, decent hardware vs. much better hardware (cache battery, speed etc), software vs. 'better' software (new comers to the game, old reliable enterprise grade like ZFS, some making HDD very easy, some making additions harder etc).
For a raidz configuration you are looking for a raid card that can be flashed into HBA mode to support the individual devices. If you are using an enclosure with a backplane the card will support the couple of dozen devices in your enclosure. If you are direct connect then however many devices that you have cable connects for ala 4i 8i 16i.
I am using an LSI M1215 8i controller for my NAS. I haven't flashed it yet but it is next on my list. Using a fat handful of s3500 600gb intel ssds (I have 7) to be mirrored and striped zfs style and spinny disks (not started yet) for long term storage la zfs2 or 3 with spares in an enclosure.
You need to decide if you need 6gbps or 12gbps and how many ports you will need. You will also need to check if the card can be flashed to HBA mode for zfs if you choose to go down that road.
That's zfs - software RAID. Kinda. Someone else will describe it for you (and probably advertise it as a silver bullet for bitrot/data retention issue).
With "classic" RAID controller - won't gonna happen. As far as I'm aware, every controller supporting expansion of a RAID, supports it in parity groups' multiples only (as in, if you have RAID5 4D+P, you can only add another 5/10/15/etc drives, adding just 3 more won't do you any good). I think some "enterprise" solutions allow for parity group expansion, but not your usual RAID cards.
I believe you can save money and get strait HBA cards, but I follow Mark Furneaux on YouTube and he had a rash of HBA card failures and went with some good ole' ebay server grade gear himself. I'm a big proponent of getting server grade (or enterprise) gear on ebay, IMO big bang for the buck or at the very least your buying something built to be reliable even if it is a bit old.
I bought a LSI 9260-8i w/battery full height bracket myself to flash into IT mode to run software RAID but then found a way to flash my z800's on-board LSI chip (1068e chip I believe) so the 9260-8i and sata cables are just sitting on a shelf in my room now-- trying to look like Wendell's office haha.
take a look at the IBM M1015. These can be flashed to an LSI controller and are a favorite of the freenas community, it sounds like it should fit your needs as well! Pretty cheap on ebay as well.
I guess I have a lot to consider! I will be watching that video you posted @Tex and go from there. I have a large university where my younger brother attends that has their own warehouse for surplus misc computer crap so I can probably snag a great deal on a RAID controller from them. If not, then eBay is always at my fingertips. Since this is something I will be doing in a few months I still have plenty of time to get caught up and become moderately informed. Thanks much to everyone who responded!
