Backup, verify, destroy: how I deleted 50 Proxmox guests in one night and could undo any of them

Description and use

Deleted 50 unused Proxmox guests, reclaimed ~700 GB, with verified backups and recoverability.

Problem

A Proxmox host had many stopped guests, many of which were unused or base images for clones, consuming ~700 GB of storage.

Outcome

Deleted 50 unused Proxmox guests and recovered ~700 GB of storage, with all backups verified and deletions reversible via backups. Additional cleanup freed ~100 GB.

Workflow

• List all stopped guests
• Grep each guest’s config for "base-<id>-" to identify base images; tag hits as keep
• For each remaining candidate: run vzdump with --mode stop, --storage <backupstore>, --compress zstd
• Verify the backup archive with zstd -t
• Destroy the guest with pct destroy <id> --purge (or qm destroy for VMs)
• Monitor backup storage free space and stop when space is tight
• Clean up orphan disks (pvesm list <storage>), old ISOs and CT templates in local, and snapshots older than a year

Evidence

Stopped is not the same as unused. A template, or a plain container someone turned into a template, is always stopped and may be the base of linked clones. Deleting it takes every clone with it.

Source

vzdump <<id>> --storage <backupstore> --compress zstd --mode stop

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zstd -t /path/to/vzdump-lxc-<<id>>-*.tar.zst # VMs: zstd -t /path/to/vzdump-qemu-<<id>>-*.vma.zst

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pct destroy <<id>> --purge # VMs: qm destroy <<id>> --purge

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Running the vzdumps at full speed made the host's busy containers laggy, so I added --bwlimit to the vzdump command.

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