Storage pools
Updated
The storage pool is where machine disks, cached images, and data volumes live. A host needs one before it can create anything.
Creating a pool
Section titled “Creating a pool”Pool creation always runs the same four steps, whether you start it in the setup wizard or later from the Storage page.
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Inventory. The host scans its disks and reports exactly what it found.
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Plan. You describe the outcome you want. Guided asks what matters: protection against a disk failure, total capacity, or keeping things separate. Advanced exposes the pool target, per-disk assignment, and the RAID layout directly.
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Review. The plan comes back with the list of devices that will be erased and the risks it carries. Nothing has happened yet at this point.
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Apply. You confirm the exact device list and risks from the review, and the host builds the pool.
If the disks change between the review and the apply, the plan is rejected and you review again. That is deliberate: a stale plan could name a device that is no longer the one you looked at.
While it runs
Section titled “While it runs”Apply reports progress as it works through wiping, building, formatting, and mounting. Ordinary work that writes to storage waits until it is finished.
If it fails and the failure is retryable, resume it. If the outcome is uncertain, the host stops and asks you to re-check first: it will observe and report before it touches anything again, rather than guessing at a half-built pool.
Managing an existing pool
Section titled “Managing an existing pool”| Action | What it does |
|---|---|
| Adopt | Take over a pool that already exists on the disks |
| Extend | Add capacity by growing the pool onto more space |
| Dissolve | Tear the pool down |
Disk health
Section titled “Disk health”The Storage page reports each disk’s health, and warns you early when a disk starts reporting problems. Check it after any unexpected reboot.
Capacity planning
Section titled “Capacity planning”Three things consume the pool, and it is worth sizing for all of them:
- Machine disks, which are full copies of the image rather than thin layers, so ten VMs from one image use ten disks’ worth of space.
- Cached images, one copy of each image you pulled.
- Snapshots, roughly the guest’s memory size each, plus disk growth afterwards. See Snapshots.