What happens when I add a disk to my ZFS pool?
(This creates a temporary replacing device which becomes a parent to the old and new disk; when the resilver completes, the replacing device is removed from the device tree and it looks like the new device was there all along.) Once the resilver completes, the old disk can be removed from the system.
Can a vdev be expanded with zpool online?
Once all disks in a vdev are replaced by larger ones, you can expand the pool by running zpool online -e or by having the autoexpand property set to on (though I wouldn’t really recommend the latter; pool expansion should be a conscious decision). So which way is better? That basically depends on your pool.
When do I need to replace my ZFS drive?
Then plan to replace those drives either on a 4-5 year schedule (due to wear) or whenever the pool goes above about 80% full (because ZFS is much, much happier when it has good headroom).
Is there a way to grow a ZFS pool?
There are basically two ways of growing a ZFS pool. This is what user1133275 is suggesting in their answer. It’s done with zpool add (which has basically the same syntax as zpool create does for specifying storage), and it works well for what it does.
How do I add a mirror to my ZFS pool?
However, you can change the level of redundancy by using the –f option. To add a new virtual device to a pool, use the zpool add command. Note – With zpool add –n, you can perform a dry run before actually adding devices. In the following example, a mirror is added to a ZFS configuration that consists of two top-level mirrored devices.
Can a cache device be mirrored in RAID-Z?
Cache devices cannot be mirrored or be part of a RAID-Z configuration. Use the zpool remove command to remove cache devices. For example: Currently, the zpool remove command only supports removing hot spares, log devices, and cache devices.