2010-10-13, 08:37
Damn good description there darkscout.
What OS do you recommend for storage server that can run ZFS nicely ?
What OS do you recommend for storage server that can run ZFS nicely ?
darkscout Wrote:What happens when you get bit-rot? What happens when your drive thinks that it is good but you're just replicating and taking parity of bad data? What happens when you lose 2 drives?
poofyhairguy Wrote:I personally am not scared of having more than one HD fail at a time because I always watch the SMART data my Unraid box emails to me and because I mix and match drives to avoid bad batches.
Quote:In fact in my newest Unraid box I am trying to collect every 1.5tb and 2tb drive on the market into a single array (and I am a WD Black 2TB away from succeeding) to avoid any one model or batch being a dude. You can't do that with ZFS.
jvdb Wrote:You're wrong. I helped a friend build a freenas box who is not concerned about losing the data on his media server. He only wants maximum storage space (nothing wasted in parity), and the ability to add drives to a single volume. He started out with a single Samsung 1.5TB (single drive stripe added to pool). Just last month we added a 2TB WD (again single drive stripe added to pool). I don't consider this wise (I've seen a lot of drives fail), but it is super easy to do.
darkscout Wrote:If any byte of a copy is duplicated, ZFS will make sure that you don't needlessly duplicate files. Say I copy 1MB tank/Pictures/1.jpg to tank/Pictures/2.jpg. On normal RAIDs (and unRAID included), you will use 2MB of data. With ZFS you still only use 1MB.
darkscout Wrote:** Glad to see the ZFS advocates finally come out. I felt like I was a loner for a while
poofyhairguy Wrote:But is there ANY WAY to configure ZFS to NOT stripe the data in the array so individual drives can be pulled out and read?
Quote:Of different sizes? I thought they all had to be the same size?
Quote:Basically what I am saying is that Unraid lets you have an array with different sized drives (and use all the space on those different sized drives). If ZFS CAN use different sized drives and use all the space on those drives please correct me. My understanding is that a ZFS array cannot grow like Unraid or RAID 5 can.
Not really a problem with a media server. A HUGE problem with a server that is acting as a business database. That is why I would never put Unraid in my office.
Quote:So basically you are saying "Sure you can replace smaller drives with larger ones, but you won't be able to use that extra space until ALL the small drives are replaced." Is that what you are saying?
Because quite frankly for home use that sucks, and is reason alone to pay for Unraid or WHS for many people.
Quote:What makes me scratch my head is the fact that so many people push an enterprise system for home use.
Quote:For media use what matters most:
-Data is reasonably secure so you don't have to rerip all your DVDs
-To be able to add whatever drive is cheapest on the market at the time you need more space to the array and use all the space on the drive no matter what you originally had in the array
-To be able to saturate a cheap gigabit network with large and constant reads from the server
-To be able to have single folders that span multiple drives
Unraid gives all that, and pretty much nothing more. ZFS can't do all that (unless you CAN use different sized drives in a single ZFS array and use all the space), but adds in a bunch of things that media users don't need.
PatrickVogeli Wrote:I already had asked thess questions, but I haven't got answers: how does freenas behave agains a multiple drive failure? Does it allow you to add drives as you need more space? Does it need raid enabled in bios or a hardware raid controller? Can you mix different type of drives (sata, ide, different sizes)?
TugboatBill Wrote:So if my XBMC client want a movie from a ZFS system does it spin up all the drives or just the one the movie is on?
TugboatBill Wrote:I have a share "Movies" on a ZFS system. I rip to it and eventually I fill it up. Can I just add another drive to it (of a larger capacity)? Is it just a simple prep the drive (format) and tell ZFS that it's available to the Movies share?
poofyhairguy Wrote:I will say that on Unraid's forum there are many users that have used the system for over 4 years (just upgrading the arrays one hard drive and mobo at a time) and not once have I read about any "bit rot." Just lots of happy customers with no data loss.
poofyhairguy Wrote:What I think you are referring to (in other comparisons I have read about ZFS vs traditional RAID) is the infamous RAID 5/6 "write hole." This problem does not affect Unraid, because Unraid is based on RAID 4. In fact, its safer than RAID 4 because its not stripped, and in most cases of data corruption in normal RAID comes from the striping of the data.
froggit Wrote:... as use of ZFS does not tie you to a specific OS.Except that it only runs properly on OpenSolaris - which is dead. I'm on your side that FreeNAS+ZFS is a fantastic solution, but lets not get crazy with the comparison. unRAID works very well for multimedia storage, and is very simple to use - that makes it extremely relevant to many even if it's lacking some enterprise level features.
teaguecl Wrote:Except that it only runs properly on OpenSolaris - which is dead. I'm on your side that FreeNAS+ZFS is a fantastic solution, but lets not get crazy with the comparison. unRAID works very well for multimedia storage, and is very simple to use - that makes it extremely relevant to many even if it's lacking some enterprise level features.
froggit Wrote:All drives spin when read from, in general, unless the movie is in cache.
When you want to expand a ZFS storage pool, you have 2 options:
1. Upgrade an existing vdev by replacing each drive within it with a larger one, or
2. Add an extra vdev using same-sized drives.
The extra capacity available from 1. or 2. above will appear within the storage pool.
The ZFS designers wanted to make storage as simple as memory. That is, if you want to add more memory to your system, you add a new RAM stick. You don't have to do anything else to make the new memory appear. There is a memory pool and your new RAM will magically appear in the new memory pool when you reboot. And that's how they wanted to make storage: easy as adding new drives, and the extra capacity appears within the storage pool.
And finally, you don't have to format drives when they are added to a ZFS storage pool. No formatting for hours and hours and hours...