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> However, there are some nice perks to having a system that runs on ZFS. Due to its frequently-snapshotting nature, it's much easier to do risky stuff without

by gh02t 10y ago

> However, there are some nice perks to having a system that runs on ZFS. Due to its frequently-snapshotting nature, it's much easier to do risky stuff without having to worry about nuking the whole system, since you can always revert to the previous snapshot (kind of like Git). Agreed, this is an amazing feature, as are jails to keep things compartmentalized. I hate having to clutter my FreeBSD home server root install with a billion dependencies for the various services it hosts, so I use jails as lightweight VMs to partition it into different service groups. It also makes it easy to back up and move jails whenever I upgrade because things are contained on ZFS subvols. For people who don't know, snapshots are also well supported on Linux, and not just in ZFS. I use it with BTRFS on my main workstation and it's saved me a few times. There is a great tool called Snapper (by the SUSE people, but it works on other distros - I use it on Arch) that automates managing snapshots and can even e.g. hook into your package manager to automatically snapshot before an upgrade. It's like Windows System Restore Points done right. https://wiki.archlinux.org/index.php/Snapper https://wiki.archlinux.org/index.php/Snapper

tombert 10y ago
While I do love Btrfs and use it on my Linux laptops, there's more to ZFS than just snapshotting. Raid-Z is a great soft-raid that allows you to lose up to 3 disks (depending on your configuration level), and `zfs send` is really useful for keeping disks synchronized on different machines.
- gh02t 10y ago
  Yep, I use both on my FreeBSD server. RAIDZ is great, though like most non-enterprise users I wish ZFS was a bit more flexible when it came to growing volumes. I also use `zfs send`, that's what I was referring to with moving jails around and it's very handy. Btrfs has similar features with `btrfs send` and RAID, though the parity RAID modes most similar to RAIDZ have kind of a troubled history (https://btrfs.wiki.kernel.org/index.php/RAID56 https://btrfs.wiki.kernel.org/index.php/RAID56) and I wouldn't recommend using Btrfs RAID5/6 for valuable data. ZFS RAIDZ is also superior in terms of reliability because it does a full-stripe write and ZFS has some other features for server use (e.g. zvols). Btrfs is more flexible with regards to growing or shrinking a RAID volume, but again the code is not considered production ready and has some pretty severe drawbacks. That said, I used Btrfs RAID5 on a small compute cluster and it's never had any issues, but if I was going to do it again I'd use ZFS there.
  - tombert 10y ago
    Yeah, wasn't trying to question your setup, I was just doing the HN thing where I have to reply and go into greater detail for ego-related reasons. I actually did not know that Btrfs had a send function, I'll have to play with that on one of my laptops.
- tracker1 10y ago
  Just want to point out two caveats wrt Raid-Z2/3, and that is have a LOT of ECC Ram (wouldn't suggest less than 16GB, and more than 32 is better). Second is if you have a hot spare, test your configuration to make sure it loads the hot spare. Aside: I ran a homebrew FreeNAS (forget the version, was several years ago now) with 12x3TB drives, without ECC, and the version of freenas had a bug that didn't pickup the drive designated as a hot spare when the first drive died... They were horrible Seagate 3tb 7200.xx drives, and they all died way too close together... in the end, lost most of the system... when I finally got around to testing the drives (didn't have the heart/energy after for a while) all but 2 had significant errors. That's more a knock against Seagate (will NEVER buy from them again) than ZFS though. Will also not likely do a homebrew nas server ever again, didn't save enough over Synololgy that made the cost savings vs. time worthwhile, but ymmv.
  - tombert 10y ago
    I've had pretty good luck on my homebrew FreeNAS server that I ran about a year ago. I only had 8GB of RAM, and I managed to lose drives and replace them without losing data...maybe the bug you had got fixed by the time I used it? Now this server runs on ZFS on Linux using Proxmox, though admittedly I did up the RAM to 32GB.
    - tracker1 10y ago
      The issue was fixed 2 versions down from the one I had started with... but there were cascading drive failures... wound up putting 4x4TB wd reds in my old synology box, managed to get a few things off of the freenas server, but it died rather painfully... would hard lock after about 10-15 minutes requiring a reboot... start copying again... after a day of that, I had most of my music, some of my commercial software and a few other things... lost all my dvd/br rips, etc... Thinking of another synology box in a few months, bumping to more or larger drives. Though, space would be less of a problem if I were willing to re-rip everything to h.265, finally got my settings for the nv encoder pretty well balanced, just a lot of time.

by gh02t 10y ago

tombert 10y ago

While I do love Btrfs and use it on my Linux laptops, there's more to ZFS than just snapshotting. Raid-Z is a great soft-raid that allows you to lose up to 3 disks (depending on your configuration level), and `zfs send` is really useful for keeping disks synchronized on different machines.

gh02t 10y ago
Yep, I use both on my FreeBSD server. RAIDZ is great, though like most non-enterprise users I wish ZFS was a bit more flexible when it came to growing volumes. I also use `zfs send`, that's what I was referring to with moving jails around and it's very handy. Btrfs has similar features with `btrfs send` and RAID, though the parity RAID modes most similar to RAIDZ have kind of a troubled history (https://btrfs.wiki.kernel.org/index.php/RAID56 https://btrfs.wiki.kernel.org/index.php/RAID56) and I wouldn't recommend using Btrfs RAID5/6 for valuable data. ZFS RAIDZ is also superior in terms of reliability because it does a full-stripe write and ZFS has some other features for server use (e.g. zvols). Btrfs is more flexible with regards to growing or shrinking a RAID volume, but again the code is not considered production ready and has some pretty severe drawbacks. That said, I used Btrfs RAID5 on a small compute cluster and it's never had any issues, but if I was going to do it again I'd use ZFS there.
- tombert 10y ago
  Yeah, wasn't trying to question your setup, I was just doing the HN thing where I have to reply and go into greater detail for ego-related reasons. I actually did not know that Btrfs had a send function, I'll have to play with that on one of my laptops.
tracker1 10y ago
Just want to point out two caveats wrt Raid-Z2/3, and that is have a LOT of ECC Ram (wouldn't suggest less than 16GB, and more than 32 is better). Second is if you have a hot spare, test your configuration to make sure it loads the hot spare. Aside: I ran a homebrew FreeNAS (forget the version, was several years ago now) with 12x3TB drives, without ECC, and the version of freenas had a bug that didn't pickup the drive designated as a hot spare when the first drive died... They were horrible Seagate 3tb 7200.xx drives, and they all died way too close together... in the end, lost most of the system... when I finally got around to testing the drives (didn't have the heart/energy after for a while) all but 2 had significant errors. That's more a knock against Seagate (will NEVER buy from them again) than ZFS though. Will also not likely do a homebrew nas server ever again, didn't save enough over Synololgy that made the cost savings vs. time worthwhile, but ymmv.
- tombert 10y ago
  I've had pretty good luck on my homebrew FreeNAS server that I ran about a year ago. I only had 8GB of RAM, and I managed to lose drives and replace them without losing data...maybe the bug you had got fixed by the time I used it? Now this server runs on ZFS on Linux using Proxmox, though admittedly I did up the RAM to 32GB.
  - tracker1 10y ago
    The issue was fixed 2 versions down from the one I had started with... but there were cascading drive failures... wound up putting 4x4TB wd reds in my old synology box, managed to get a few things off of the freenas server, but it died rather painfully... would hard lock after about 10-15 minutes requiring a reboot... start copying again... after a day of that, I had most of my music, some of my commercial software and a few other things... lost all my dvd/br rips, etc... Thinking of another synology box in a few months, bumping to more or larger drives. Though, space would be less of a problem if I were willing to re-rip everything to h.265, finally got my settings for the nv encoder pretty well balanced, just a lot of time.