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Maybe it’s because I’ve already been using it for years, but I don’t really consider ZFS any more difficult to manage than the DM/LVM/*FS stack I work with on m

Maybe it’s because I’ve already been using it for years, but I don’t really consider ZFS any more difficult to manage than the DM/LVM/*FS stack I work with on most Linux systems. Compared to just running gdisk and using raw partitions - sure, but I’ve been using LVM for over a decade now.

zaarn 8y ago
ZFS is a lot more complicated if you're expecting the average consumer to handle it. It doesn't even handle 1-disk-storage expansion. Even Synology and QNAP now have plug-and-play solutions to expand a RAID one disk at a time. You can even start plugging in higher capacity disks and once you have enough extra parity, the higher capacity becomes used magically. No need for wasteful RAID10/50/60 setups. Just plug in more drives.
- RantyDave 8y ago
  1 disk storage expansion? You do 'zpool add' IIRC.
  - zaarn 8y ago
    That doesn't give you RAID protection, sadly, with mdadm and LVM you can add a single disk into an existing array, ZFS requires you to pull up a new RAID array (vdev) and at minimum 2 devices if you want something better than a RAID 0.
    - snuxoll 8y ago
      I don’t run Z-RAID 5/6 personally so it’s been a non issue, but that functionality is in the works right now.
      - zaarn 8y ago
        It is in the works but the question is how many years until it's stable and available to all end users and how well it works (IIRC from a talk on this topic, it had some limitations as well). This also affects the RAID1 setup, any storage expansion requires 2 disk to pull up a new RAID1 into the pool.
        snuxoll 8y ago
        Mirrors, unlike RAID-Z, can be added later. They can even be detached from the pool as long as one mirror from the device remains.
      - PhantomGremlin 8y ago
        in the works right now I don't know where you read that, but don't be fooled. That functionality has been "in the works" for quite a long time. But it hasn't yet appeared. In the past it has been said that something called "block pointer rewrite" was a prerequisite. Just google for that. Here's some 10 year old information about it. At that time it was already a "frustratingly frequent request." I stopped searching when I found something 10 years old, but I'm sure you with some effort you could go back much further than that. https://blogs.oracle.com/ahl/expand-o-matic-raid-z https://blogs.oracle.com/ahl/expand-o-matic-raid-z
- laumars 8y ago
  > No need for wasteful RAID10/50/60 setups. Just plug in more drives. Those RAID set ups are only "wasteful" if you don't need that level of redundancy (ie the number of disks that can fail at the same time). Most home users only really need 1 redundancy disk (actually most home users don't even need that) but a production database server is another matter entirely. For clarity, the reason we have redundancy drives isn't to mitigate the need for backups; it's the mitigate the likelihood of downtime while you rebuild your storage array from a backup. Which is why most home users don't even need 1 redundancy disk - they just need to be disciplined in backing important stuff up.
- rleigh 8y ago
  Expanding 1-disc storage is trivial. Scenario 1: Replace smaller disc with bigger disc. Add new disc as mirror to vdev. Wait for it to resilver. Remove original disc from vdev. Pool will autoexpand to new disc size or can be manually expanded otherwise. Scenario 2: Expand virtual storage. Use LVM lvresize, or expand VM virtual disc. Pool will autoexpand to new volume size; may need manual triggering if the system doesn't pick up the new device size automatically. Or you can do the same as for physical discs. Add new virtual storage as mirror, resilver, then drop the old storage.

zaarn 8y ago

ZFS is a lot more complicated if you're expecting the average consumer to handle it. It doesn't even handle 1-disk-storage expansion. Even Synology and QNAP now have plug-and-play solutions to expand a RAID one disk at a time. You can even start plugging in higher capacity disks and once you have enough extra parity, the higher capacity becomes used magically. No need for wasteful RAID10/50/60 setups. Just plug in more drives.

RantyDave 8y ago
1 disk storage expansion? You do 'zpool add' IIRC.
- zaarn 8y ago
  That doesn't give you RAID protection, sadly, with mdadm and LVM you can add a single disk into an existing array, ZFS requires you to pull up a new RAID array (vdev) and at minimum 2 devices if you want something better than a RAID 0.
  - snuxoll 8y ago
    I don’t run Z-RAID 5/6 personally so it’s been a non issue, but that functionality is in the works right now.
    - zaarn 8y ago
      It is in the works but the question is how many years until it's stable and available to all end users and how well it works (IIRC from a talk on this topic, it had some limitations as well). This also affects the RAID1 setup, any storage expansion requires 2 disk to pull up a new RAID1 into the pool.
      - snuxoll 8y ago
        Mirrors, unlike RAID-Z, can be added later. They can even be detached from the pool as long as one mirror from the device remains.
    - PhantomGremlin 8y ago
      in the works right now I don't know where you read that, but don't be fooled. That functionality has been "in the works" for quite a long time. But it hasn't yet appeared. In the past it has been said that something called "block pointer rewrite" was a prerequisite. Just google for that. Here's some 10 year old information about it. At that time it was already a "frustratingly frequent request." I stopped searching when I found something 10 years old, but I'm sure you with some effort you could go back much further than that. https://blogs.oracle.com/ahl/expand-o-matic-raid-z https://blogs.oracle.com/ahl/expand-o-matic-raid-z
laumars 8y ago
> No need for wasteful RAID10/50/60 setups. Just plug in more drives. Those RAID set ups are only "wasteful" if you don't need that level of redundancy (ie the number of disks that can fail at the same time). Most home users only really need 1 redundancy disk (actually most home users don't even need that) but a production database server is another matter entirely. For clarity, the reason we have redundancy drives isn't to mitigate the need for backups; it's the mitigate the likelihood of downtime while you rebuild your storage array from a backup. Which is why most home users don't even need 1 redundancy disk - they just need to be disciplined in backing important stuff up.
rleigh 8y ago
Expanding 1-disc storage is trivial. Scenario 1: Replace smaller disc with bigger disc. Add new disc as mirror to vdev. Wait for it to resilver. Remove original disc from vdev. Pool will autoexpand to new disc size or can be manually expanded otherwise. Scenario 2: Expand virtual storage. Use LVM lvresize, or expand VM virtual disc. Pool will autoexpand to new volume size; may need manual triggering if the system doesn't pick up the new device size automatically. Or you can do the same as for physical discs. Add new virtual storage as mirror, resilver, then drop the old storage.