qm-disk-rescan

Rescan all storages and update disk sizes and unused disk images

$ qm [[di|disk]] [[resc|rescan]]

$ qm [[di|disk]] [[resc|rescan]] --dryrun

$ qm [[di|disk]] [[resc|rescan]] --vmid [100]

qm-disk-rescan

qm-disk-rescan is a specialized utility command primarily used within the Proxmox Virtual Environment (Proxmox VE) to detect and update information about available storage devices.

Its main purpose is to trigger a rescan of the underlying storage infrastructure, allowing Proxmox to discover newly added disks, partitions, or changes to existing block devices without requiring a full system reboot.

This command is particularly useful when physically adding new hard drives, SSDs, or SAN LUNs to a Proxmox node, or when performing changes at the hardware level that affect disk visibility.

Upon execution, it attempts to identify new block devices and updates Proxmox's internal storage view, which is then reflected in the web interface and command-line tools. It helps ensure that Proxmox VE's storage subsystem is aware of the current physical disk layout, enabling these devices to be used for virtual machine storage, LVM volume groups, ZFS pools, or other storage types supported by Proxmox.

. This command is specific to the Proxmox Virtual Environment and is not a general-purpose Linux utility found on all distributions.
. It typically requires root privileges (or `sudo`) to execute successfully, as it interacts directly with system hardware and storage layers.
. While it triggers a rescan, it may not resolve all underlying issues if there are problems with device drivers, kernel modules, or hardware connectivity.
. It primarily helps Proxmox update its internal view; sometimes additional steps (e.g., `pvcreate`, `vgcreate`, `zpool create`) are needed to prepare the newly detected devices for use.

qm-disk-rescan is designed to be used within a Proxmox VE server environment. While it can be executed from the command line, its functionality is also integrated into the Proxmox web interface (e.g., when adding storage or creating new LVM/ZFS pools), where it often runs automatically in the background to update the storage view for the administrator.

The qm-disk-rescan utility has been an integral part of the Proxmox VE distribution since its earlier versions. It was developed to address the common operational need for system administrators to hot-add or modify storage without requiring disruptive reboots. Its development reflects Proxmox VE's focus on ease of management and robust virtualization infrastructure.

lsblk(8), fdisk(8), parted(8), udevadm(8), sg_rescan(8), rescan-scsi-bus.sh, pve(1)