3 ms·

> the storage is small What did you expect here? 50% is typical trade off these days in disk arrays.

Bromlife 11y ago
Is this because of hot swaps? I would be pretty disappointed by a 50% usable for RAID6. But I don't include the hotswap(s) in this equation.
- windowsworkstoo 11y ago
  Right I was talking about RAID10, the only RAID that is sensible to use these days... Even with ZFS as I understand it, you should just set up your storage pool then mirror it and be done....boom 50%
  - voltagex_ 11y ago
    Yeah I ended up going with mirrored vdevs for the ability to expand to 6TB drives later... then I was told (in IRC) that a single bit-flip would cause a complete pool failure.
    - simcop2387 11y ago
      I'm curious how that is?
    - cmurf 11y ago
      Uhh if they're mirrored, a bit flip is not only detected by ZFS but also corrected, whether it happens passively during a normal file read, or scrubbing, or presumably a resilver.
      - deleted 11y ago
        [deleted]
voltagex_ 11y ago
Yeah, you're right. But I'd already blown my budget and then I hear "oh you should have used 6x3TB or 6x4TB in RAIDZ2". ...it's a 4 bay NAS, for home use.
- Amezarak 11y ago
  I don't want to be That Guy, but the number of drives that fit best with each RAIDZ-level is documented and is the reason why I decided to finish out with six drives before I dropped a couple grand on my setup. (6x4 TB, 14TB usable space, also for home use. I did start with a 2x4TB mirror and expand several months later.) And a mobo and case with six SATA ports is not at all hard to find and IIRC is exactly what the "recommended FreeNAS hardware" thing comes with. One thing that is definitely true about FreeNAS is that you should read all the documentation and advice on the forums before you order a single part.
benjaminl 11y ago
You go from 16 terabytes to 14.5 tebibytes right out of the gate. And then if you use Raid-Z2 (Raid 6), which uses 2 disks for parity, on a four disk set, half of your drives will be used for parity. This was of course the right call, because with the size of current drives Raid-Z1 (Raid 5) is really risky. Personally on my ZFS based home built server I use mirroring, due to the well publicized issue with the extreme difficulty of increasing the size of ZFS's VDEVs. Which has the same 50% usable space reduction.
- voltagex_ 11y ago
  Yep, I've gone to a pair of vdevs too. I'm calming down now, even if I had to format an external drive to ZFS just to get it to mount (yes, yes, I know, USB is terrible and I'm going to lose all my data). I would not recommend FreeNAS for a home user.
  - js2 11y ago
    Why not? I've been extremely happy with FreeNAS. I have two mirrored pairs of disks in mine. Besides performing NAS duties with aplomb, I also have a half dozen jails running various HTPC tasks such as hosting Plex.
  - benjaminl 11y ago
    You are making me very glad that I went with Ubuntu rather than a NAS oriented OS like FreeNAS.
    - fsckin 11y ago
      My first NAS build used FreeNAS. For a simple Samba box, it's just about perfect. However, I wanted my NAS to run a few more services than the ones that were easily available and pre-built "blessed" plugins. I had a low spec CPU in the NAS and went through hell and back to build/install/jail a few packages from source (along with their dependancies). It was a steep learning curve and wasn't terribly fun. When it came time to add a second NAS, I chose Ubuntu and ZFS on Linux. It's been running like a champ for well over a year without a single hiccup. I don't think I've even built a single package ever. Best of both worlds, in my opinion.

Is this because of hot swaps? I would be pretty disappointed by a 50% usable for RAID6. But I don't include the hotswap(s) in this equation.

windowsworkstoo 11y ago
Right I was talking about RAID10, the only RAID that is sensible to use these days... Even with ZFS as I understand it, you should just set up your storage pool then mirror it and be done....boom 50%
- voltagex_ 11y ago
  Yeah I ended up going with mirrored vdevs for the ability to expand to 6TB drives later... then I was told (in IRC) that a single bit-flip would cause a complete pool failure.
  - simcop2387 11y ago
    I'm curious how that is?
  - cmurf 11y ago
    Uhh if they're mirrored, a bit flip is not only detected by ZFS but also corrected, whether it happens passively during a normal file read, or scrubbing, or presumably a resilver.
    - deleted 11y ago
      [deleted]

voltagex_ 11y ago

Yeah, you're right. But I'd already blown my budget and then I hear "oh you should have used 6x3TB or 6x4TB in RAIDZ2". ...it's a 4 bay NAS, for home use.

Amezarak 11y ago
I don't want to be That Guy, but the number of drives that fit best with each RAIDZ-level is documented and is the reason why I decided to finish out with six drives before I dropped a couple grand on my setup. (6x4 TB, 14TB usable space, also for home use. I did start with a 2x4TB mirror and expand several months later.) And a mobo and case with six SATA ports is not at all hard to find and IIRC is exactly what the "recommended FreeNAS hardware" thing comes with. One thing that is definitely true about FreeNAS is that you should read all the documentation and advice on the forums before you order a single part.

benjaminl 11y ago

You go from 16 terabytes to 14.5 tebibytes right out of the gate. And then if you use Raid-Z2 (Raid 6), which uses 2 disks for parity, on a four disk set, half of your drives will be used for parity. This was of course the right call, because with the size of current drives Raid-Z1 (Raid 5) is really risky. Personally on my ZFS based home built server I use mirroring, due to the well publicized issue with the extreme difficulty of increasing the size of ZFS's VDEVs. Which has the same 50% usable space reduction.

voltagex_ 11y ago
Yep, I've gone to a pair of vdevs too. I'm calming down now, even if I had to format an external drive to ZFS just to get it to mount (yes, yes, I know, USB is terrible and I'm going to lose all my data). I would not recommend FreeNAS for a home user.
- js2 11y ago
  Why not? I've been extremely happy with FreeNAS. I have two mirrored pairs of disks in mine. Besides performing NAS duties with aplomb, I also have a half dozen jails running various HTPC tasks such as hosting Plex.
- benjaminl 11y ago
  You are making me very glad that I went with Ubuntu rather than a NAS oriented OS like FreeNAS.
  - fsckin 11y ago
    My first NAS build used FreeNAS. For a simple Samba box, it's just about perfect. However, I wanted my NAS to run a few more services than the ones that were easily available and pre-built "blessed" plugins. I had a low spec CPU in the NAS and went through hell and back to build/install/jail a few packages from source (along with their dependancies). It was a steep learning curve and wasn't terribly fun. When it came time to add a second NAS, I chose Ubuntu and ZFS on Linux. It's been running like a champ for well over a year without a single hiccup. I don't think I've even built a single package ever. Best of both worlds, in my opinion.