Originally Posted by ajhieb
Most of the solutions aren't calculating parity in real-time either, so that point is pretty much moot.
I'd also suggest that RAID isn't particularly complicated, at least from an end user standpoint. The real drawback is usually hardware expense, and the caveat that all drives (in the same array) need to be the same size. (I assume that's what you meant by inflexible)
That said, setting up my RAID system was trivially easy, and zero maintenance on my part. It checks drive health in the background, and parity calculations are done in real time. Drive pooling isn't necessary as it is inherent to RAID. It certainly isn't for everybody, but I think I paid about $250 total for my RAID controller and 16bay hotswap chassis (system pulls) and it has suited my needs rather well. I currently have a 4x4TB RAID 5 array, a 6x6TB RAID 5 array, and 6 empty bays. When the price comes down on 8 or 10TB drives, I'll add another 6 drive array, and I'll be set for several more years.
Sorry for the tangent. I just have to take up for my RAID setup once and a while.
That said, The stuff on my 4x4TB array, is my "important" stuff that I also have backed up on burnt media as well as cloud storage. My 6x6TB array is all media that I've ripped so I consider the data there to be the backup of my original media. The parity in this case is just to mitigate the risk of losing time re-ripping my media vs the probability of a drive failure. I think that's true of most people (here) using any solution involving parity. (Maintaining uptime is also a benefit of real-time parity but not really a big selling point in this arena) If you asked people point blank if they would pay an extra $100, $150, $200 (whatever the price is for an parity drive) as insurance against ripping a bunch of their media again, it's a no-brainer.
Anyway, not all of that was directed at you, @Defcon
I know you know most of that, but just clarifying for anyone reading.
PS. The only reason that I haven't moved from traditional RAID to unRAID is the lack of additional multiple parity drives and/or the inability to create multiple single-parity arrays. Either one would eliminate my need for the other, but I need at least one to feel comfortable.
Originally Posted by Defcon
A full backup is always desirable but not everyone can do that. Parity is far more preferable than the traditional solutions like Raid/ZFS which are inflexible and complicated. Even if you have backups you will not be taking them in real time, and parity can help in event of failure anytime.
I have a feeling this is going to be a long post but it seems that OP is following a lot of the same path in the evolution of his media server that I went on. So using my media server as an example let me throw my $.02 in the ring.
I started out with unRAID a few years ago, building it out of old parts I had lying around in my garage. It ran fine on my old AMD Thunderbird and I had even read of people using single core Semprons with great success. However, because unRAID is its own self-contained environment it just became a storage box for my media and I had to use my desktop PC to run my media server software (Mezzmo) since it was Windows based and I needed a CPU with a little more power to transcode for video streaming. That meant I had to leave two PCs on if I wanted to stream my media. I also hated that I had to start with empty drives and couldn't just import a drive into the array.
So, I eventually got an AMD FX-6100 CPU and ran WHS 2011 on it. It ran Mezzmo fine and I installed FlexRAID. I ran single parity (RAID-5). FlexRAID has a decent (albeit, not really intuitive GUI) and it worked fairly well but I got really slow transfer speeds to and from the FlexRAID array; fast enough to watch or listen to the media but reading and writing from the file structure was much slower than I had even experienced with unRAID. At some point, I dumped WHS 2011 and just migrated my FlexRAID setup to Win 7 Pro.
Everything ran fine for a few years except for a few minor glitches with FlexRAID here and there. FlexRAID seems to have had globally poor support and I can say that my experience was pretty similar. It seems to be a one man show (a guy named Brahim) and he seemed greatly overwhelmed by the project but he had a novel way of talking over your head and then getting annoyed if you asked for clarification or for follow-up issues. If you are familiar with Saturday Night Live think 'Nick Burns, the Company's Computer Guy'.
Over time I added more and more drives, an additional SATA card or two, decided to go Dual-Parity and finally when I upgraded the CPU to an AMD 8350 I was unable to register FlexRAID. After a couple of emails to FlexRAID they told me that I had upgraded too much and now I was pretty much using FlexRAID on a different computer than had originally been licensed. Long story short, I ended up having to repurchase FlexRAID and it left a bad taste in my mouth. I continued to deal with FlexRAID's quirks for another year or so until I finally got fed up a month ago. I just had so many issues with parity updates, Validations, etc. that I finally just tore down the array and moved the array to SnapRAID and continued to use only FlexRAID's pooling features but it just never felt like a good match. I can't really put my finger on it, but it was obvious that FlexRAID was never meant to be a pooling only software.
Now, I have uninstalled FlexRAID and have been running SnapRAID with StableBit DrivePool for about 3 weeks. SnapRAID w/Elucidate has been so transparent that I am almost unsure that it is actually working. There were a couple of occasions where I had to reinstall FlexRAID and the whole initialization of the database would have my media server down for an entire day or more. With SnapRAID and DrivePool that is not a problem. I can create the Pool and have it available for sharing within minutes. SnapRAID can then build the array in the background while DrivePool keeps everything up and online.
Which takes us to "RAID is not backup".
True, but I don't need a full backup. I keep my important documents, photos and music on my server, but my BD and DVD Rips take up 90% of the space. I can/do backup everything but my video files to a 3TB HDD as well as automatic cloud storage (SpiderOak). If I had a catastrophic failure, the important stuff is safe and I can always rerip everything. In reality, I would never rerip everything since that would probably takes month on end but I guess the backups could be considered to be in boxes in the garage. In this situation, dual parity is plenty of protection.
With my new setup of SnapRAID/DrivePool, I am considering just getting the Stablebit Suite because the DriveScanner is a pretty nice piece of software and the CloudDrive looks pretty slick. It encrypts data automatically and then uploads it to the cloud storage of my choice. This pretty much nullifies my desire for SpiderOak's encrypted storage. I just haven't settled on a Cloud Service, yet.
In had also tried FreeNAS (ZFS RAID) way back when I was trying unRAID. It was nice and hardy but I couldn't import drives with existing data and every drive had to be the same size or else you lose storage space. Additionally, the hardware requirements for ZFS tended to be a little less budget friendly. Expanding the array with unRAID, FlexRAID and SnapRAID is also a snap versus having to break down your array and rebuild or just create a new array and import to a pool like you would have to do with ZFS or Hardware.