Page MenuHomeSoftware Heritage
Create Task
Maniphest T1501

Phantom device mapper volume usage in Proxmox: logical volume is used by another device
Closed, MigratedEdits Locked
Actions

Description

Virtual disk migration on Proxmox:beaubourg from beaubourg-ssd to Ceph fails with this kind of error:

can't deactivate LV '/dev/ssd/vm-107-disk-0':   Logical volume ssd/vm-107-disk-0 is used by another device.
volume deactivation failed: beaubourg-ssd:vm-107-disk-0 at /usr/share/perl5/PVE/Storage.pm line 1042.

It has been observed with vm-102-disk-0 and vm-107-disk-0 so far.

Related Objects
Search...

Event Timeline

ftigeot changed the task status from Open to Work in Progress.Jan 29 2019, 2:08 PM
ftigeot triaged this task as High priority.
ftigeot created this task.
ftigeot updated the task description. (Show Details)Jan 31 2019, 2:54 PM
ftigeot added a comment.Jan 31 2019, 5:31 PM

Trying to manually disable the logical volume in question fails with the same error message

lvchange -a n /dev/ssd/vm-107-disk-0
Logical volume ssd/vm-107-disk-0 is used by another device.
ftigeot changed the status of subtask T1509: Phantom device mapper volume usage in Proxmox: local storage is not available on target node from Open to Work in Progress.Feb 1 2019, 10:55 AM
ftigeot closed subtask T1509: Phantom device mapper volume usage in Proxmox: local storage is not available on target node as Resolved.Feb 1 2019, 11:06 AM
ftigeot renamed this task from Phantom device mapper volume usage in Proxmox to Phantom device mapper volume usage in Proxmox: logical volume is used by another device.Feb 1 2019, 11:20 AM
ftigeot added a comment.Jun 24 2019, 4:50 PM

This behavior appears to be caused by partitions present on top of device mappers devices.
These partitions in turn are used to create other dm devices and these latest device keep an open reference to the base one.

lsof does not show anything, only dmsetup info reports them.
A small example:

# dmsetup info
Name:              ssd-vm--210--disk--1p1
State:             ACTIVE
Read Ahead:        256
Tables present:    LIVE
Open count:        0
Event number:      0
Major, minor:      253, 30
Number of targets: 1
UUID: part1-LVM-huge-amount-of-digits-and-letters

Name:              ssd-vm--210--disk--1
State:             ACTIVE
Read Ahead:        8192
Tables present:    LIVE
Open count:        2
Event number:      0
Major, minor:      253, 9
Number of targets: 2
UUID: LVM-more-digits-and-letters

In this example, ssd-vm--210--disk--1 is opened twice:

  • once by the program using it to create a virtual machine
  • once by the ssd-vm--210--disk--1p1 device mapper device
ftigeot closed this task as Resolved.Jun 24 2019, 4:53 PM

The solution to this problem is to first identify the partition devices and then remove them:
dmsetup remove ssd-vm--100--disk--2p1

Regular disk image devices can then be removed in the same way or with traditional lvremove commands.

gitlab-migration changed the task status from Resolved to Migrated.Oct 19 2022, 5:55 PM
gitlab-migration claimed this task.
gitlab-migration added a subscriber: gitlab-migration.

This task has been migrated to GitLab.

gitlab-migration changed the status of subtask T1509: Phantom device mapper volume usage in Proxmox: local storage is not available on target node from Resolved to Migrated.Oct 19 2022, 5:55 PM
About · Developer information · Legal