[Bug 2080474] Re: ubuntu installation failing for systems having SAN disk
Olivier Gayot
2080474 at bugs.launchpad.net
Thu May 21 16:49:43 UTC 2026
** Description changed:
+ [ Impact ]
+ When booting an affected Ubuntu Server installer ISO on a system where a
+ multipath device is used as a LVM PV, installing Ubuntu is not possible.
+
+ Such a situation happens when a previous *LVM* installation of any OS (i.e., not
+ necessarily Ubuntu) was done on a multipath disk, present on the system.
+
+ The symptoms typically include:
+ * a crash of the Subiquity client
+ * the following error in the journal:
+ ```
+ ubuntu-server multipathd[941]: mpatha: addmap [0 16777216 multipath 0 0 2 1 service-time 0 1 1 8:0 1 service-time 0 1 1 8:16 1]
+ ubuntu-server multipathd[941]: libdevmapper: ioctl/libdm-iface.c(1990): device-mapper: reload ioctl on mpatha (252:1) failed: Device or resource busy
+ ```
+ * the VG device mapper node exists (e.g., ubuntu-vg) but the multipath one does not (e.g., mpatha)
+
+ Explanation
+ -----------
+
+ Although LVM support is included in the initramfs of the installer ISO,
+ multipath support is not. As a result, during the transition out of the
+ initramfs, LVM VGs are activated using an individual underlying path device
+ instead of the consolidated multipath device mapper node.
+
+ Example
+ -------
+ Let's assume /dev/sda and /dev/sdb refer to the same disk via different
+ paths. It is intended that sda and sdb are consolidated under a multipath
+ device node, which in turn should be used as a PV.
+
+ Excepted result in the live environment
+ ---------------------------------------
+
+ /dev/sda --> consolidated under mpatha
+ /dev/sdb --> consolidated under mpatha
+
+ /dev/mapper/mpatha --> used as the PV of ubuntu-vg
+
+ /dev/mapper/ubuntu-vg --> the VG that uses mpatha as the PV
+
+ Actual result on affected ISO
+ -----------------------------
+
+ /dev/sda --+
+ /dev/sdb ----> one of these is used as the PV for ubuntu-vg
+
+ /dev/mapper/mpatha <-- does not exist
+
+ /dev/mapper/ubuntu-vg (uses /dev/sda or /dev/sdb as the PV)
+
+ [ Proposed fix ]
+
+ * Since 25.10, we added support to multipath in the initramfs of the Ubuntu Server ISOs.
+ * This would correspond to a livecd-rootfs SRU along with a multipath-tools fix.
+
+ [ Test Plan ]
+
+ TODO
+
+ [ Where problems could occur? ]
+
+ * Bringing multipath support in the initramfs could slightly slow down the
+ boot process of the ISO. Nevertheless, 25.10 and 26.04 Ubuntu
+ Server ISOs have had multipath-support in the initramfs, and no measurable
+ slow down has been experienced.
+
+
+ [ Other Info ]
+
+ * For existing affected ISOs, there is a workaround:
+ 1. open a shell in the installer environment (one can hit F2 in the
+ Subiquity TUI)
+ 2. Delete the relevant VG using `dmsetup remove`:
+ $ sudo dmremove /dev/mapper/<vg>
+ 3. Restart multipathd using:
+ $ sudo systemctl restart multipathd
+ 4. Finally, restart Subiquity:
+ $ sudo snap restart subiquity
+ * Alternatively, users can wipe the affected disk and then restart he installer (but this involves manually erasing data from the disk).
+
+ [ Original description ]
+
== Comment: - Anushree Mathur ==
OS: 24.04 LTS (Noble Numbat)
I started the Ubuntu installation for 24.04 LTS (Noble Numbat) on L1(HOST) having SAN disk, it failed with the following error just after I chose the disk.
Ubuntu 24.04 LTS ubuntu-server hvc0
-
- connecting...
- waiting for cloud-init...
+ connecting...
+ waiting for cloud-init...
generating crash report
report saved to /var/crash/1724388235.797082424.ui.crash
Traceback (most recent call last):
- File "/snap/subiquity/5745/lib/python3.10/site-packages/subiquity/client/controllers/filesystem.py", line 273, in _guided_choice
- self.ui.set_body(FilesystemView(self.model, self))
- File "/snap/subiquity/5745/lib/python3.10/site-packages/subiquity/ui/views/filesystem/filesystem.py", line 485, in __init__
- self.refresh_model_inputs()
- File "/snap/subiquity/5745/lib/python3.10/site-packages/subiquity/ui/views/filesystem/filesystem.py", line 540, in refresh_model_inputs
- self.avail_list.refresh_model_inputs()
- File "/snap/subiquity/5745/lib/python3.10/site-packages/subiquity/ui/views/filesystem/filesystem.py", line 417, in refresh_model_inputs
- for obj, cells in summarize_device(device, filter):
- File "/snap/subiquity/5745/lib/python3.10/site-packages/subiquity/ui/views/filesystem/helpers.py", line 32, in summarize_device
- anns = labels.annotations(device) + labels.usage_labels(device)
- File "/snap/subiquity/5745/usr/lib/python3.10/functools.py", line 889, in wrapper
- return dispatch(args[0].__class__)(*args, **kw)
- File "/snap/subiquity/5745/lib/python3.10/site-packages/subiquity/common/filesystem/labels.py", line 100, in _annotations_vg
- member = next(iter(vg.devices))
+ File "/snap/subiquity/5745/lib/python3.10/site-packages/subiquity/client/controllers/filesystem.py", line 273, in _guided_choice
+ self.ui.set_body(FilesystemView(self.model, self))
+ File "/snap/subiquity/5745/lib/python3.10/site-packages/subiquity/ui/views/filesystem/filesystem.py", line 485, in __init__
+ self.refresh_model_inputs()
+ File "/snap/subiquity/5745/lib/python3.10/site-packages/subiquity/ui/views/filesystem/filesystem.py", line 540, in refresh_model_inputs
+ self.avail_list.refresh_model_inputs()
+ File "/snap/subiquity/5745/lib/python3.10/site-packages/subiquity/ui/views/filesystem/filesystem.py", line 417, in refresh_model_inputs
+ for obj, cells in summarize_device(device, filter):
+ File "/snap/subiquity/5745/lib/python3.10/site-packages/subiquity/ui/views/filesystem/helpers.py", line 32, in summarize_device
+ anns = labels.annotations(device) + labels.usage_labels(device)
+ File "/snap/subiquity/5745/usr/lib/python3.10/functools.py", line 889, in wrapper
+ return dispatch(args[0].__class__)(*args, **kw)
+ File "/snap/subiquity/5745/lib/python3.10/site-packages/subiquity/common/filesystem/labels.py", line 100, in _annotations_vg
+ member = next(iter(vg.devices))
StopIteration
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
- File "/snap/subiquity/5745/usr/bin/subiquity", line 8, in <module>
- sys.exit(main())
- File "/snap/subiquity/5745/lib/python3.10/site-packages/subiquity/cmd/tui.py", line 158, in main
- asyncio.run(run_with_loop())
- File "/snap/subiquity/5745/usr/lib/python3.10/asyncio/runners.py", line 44, in run
- return loop.run_until_complete(main)
- File "/snap/subiquity/5745/usr/lib/python3.10/asyncio/base_events.py", line 649, in run_until_complete
- return future.result()
- File "/snap/subiquity/5745/lib/python3.10/site-packages/subiquity/cmd/tui.py", line 156, in run_with_loop
- await subiquity_interface.run()
- File "/snap/subiquity/5745/lib/python3.10/site-packages/subiquity/client/client.py", line 403, in run
- await super().run()
- File "/snap/subiquity/5745/lib/python3.10/site-packages/subiquitycore/tui.py", line 351, in run
- await super().run()
- File "/snap/subiquity/5745/lib/python3.10/site-packages/subiquitycore/core.py", line 134, in run
- raise exc
+ File "/snap/subiquity/5745/usr/bin/subiquity", line 8, in <module>
+ sys.exit(main())
+ File "/snap/subiquity/5745/lib/python3.10/site-packages/subiquity/cmd/tui.py", line 158, in main
+ asyncio.run(run_with_loop())
+ File "/snap/subiquity/5745/usr/lib/python3.10/asyncio/runners.py", line 44, in run
+ return loop.run_until_complete(main)
+ File "/snap/subiquity/5745/usr/lib/python3.10/asyncio/base_events.py", line 649, in run_until_complete
+ return future.result()
+ File "/snap/subiquity/5745/lib/python3.10/site-packages/subiquity/cmd/tui.py", line 156, in run_with_loop
+ await subiquity_interface.run()
+ File "/snap/subiquity/5745/lib/python3.10/site-packages/subiquity/client/client.py", line 403, in run
+ await super().run()
+ File "/snap/subiquity/5745/lib/python3.10/site-packages/subiquitycore/tui.py", line 351, in run
+ await super().run()
+ File "/snap/subiquity/5745/lib/python3.10/site-packages/subiquitycore/core.py", line 134, in run
+ raise exc
RuntimeError: coroutine raised StopIteration
Ubuntu 24.04 LTS ubuntu-server hvc0
-
- connecting...
+ connecting...
ProblemType: Bug
Architecture: ppc64el
CrashDB: {'impl': 'launchpad', 'project': 'subiquity'}
- I tried following 2 installation methods, it is failing in both the ways:
+ I tried following 2 installation methods, it is failing in both the ways:
1) kexec method
2) attaching vdvd and starting installer
NOTE: It is happening only when the system has SAN disks otherwise this installation worked fine.
I will be attaching the crash report for this!
== Comment:- Hariharan T S ==
- Verified the following cases.
+ Verified the following cases.
Installation on Disk from VIOS - PASSED
Installatoin on Disk from VIOS and system had Disks from SAN - FAILED
Installation on Disk from SAN and system ahd Disk from VIOS - FAILED
== Comment:- Vaibhav Jain ==
Problem seems to happening when Subuquity enters the disk partition view. The system has a SAN disk and an existing Mullti Path DM volume on it.
Mirroring to distro
** Summary changed:
- ubuntu installation failing for systems having SAN disk
+ [SRU] ubuntu installation over a multipath disk with LVM
** Summary changed:
- [SRU] ubuntu installation over a multipath disk with LVM
+ [SRU] cannot install Ubuntu Server over a multipath disk used as an LVM PV
--
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to livecd-rootfs in Ubuntu.
https://bugs.launchpad.net/bugs/2080474
Title:
[SRU] cannot install Ubuntu Server over a multipath disk used as an
LVM PV
Status in subiquity:
Invalid
Status in The Ubuntu-power-systems project:
Fix Released
Status in livecd-rootfs package in Ubuntu:
Fix Released
Status in multipath-tools package in Ubuntu:
Fix Released
Status in subiquity package in Ubuntu:
Invalid
Status in livecd-rootfs source package in Noble:
Confirmed
Status in multipath-tools source package in Noble:
Invalid
Status in subiquity source package in Noble:
Invalid
Bug description:
[ Impact ]
When booting an affected Ubuntu Server installer ISO on a system where a
multipath device is used as a LVM PV, installing Ubuntu is not possible.
Such a situation happens when a previous *LVM* installation of any OS (i.e., not
necessarily Ubuntu) was done on a multipath disk, present on the system.
The symptoms typically include:
* a crash of the Subiquity client
* the following error in the journal:
```
ubuntu-server multipathd[941]: mpatha: addmap [0 16777216 multipath 0 0 2 1 service-time 0 1 1 8:0 1 service-time 0 1 1 8:16 1]
ubuntu-server multipathd[941]: libdevmapper: ioctl/libdm-iface.c(1990): device-mapper: reload ioctl on mpatha (252:1) failed: Device or resource busy
```
* the VG device mapper node exists (e.g., ubuntu-vg) but the multipath one does not (e.g., mpatha)
Explanation
-----------
Although LVM support is included in the initramfs of the installer ISO,
multipath support is not. As a result, during the transition out of the
initramfs, LVM VGs are activated using an individual underlying path device
instead of the consolidated multipath device mapper node.
Example
-------
Let's assume /dev/sda and /dev/sdb refer to the same disk via different
paths. It is intended that sda and sdb are consolidated under a multipath
device node, which in turn should be used as a PV.
Excepted result in the live environment
---------------------------------------
/dev/sda --> consolidated under mpatha
/dev/sdb --> consolidated under mpatha
/dev/mapper/mpatha --> used as the PV of ubuntu-vg
/dev/mapper/ubuntu-vg --> the VG that uses mpatha as the PV
Actual result on affected ISO
-----------------------------
/dev/sda --+
/dev/sdb ----> one of these is used as the PV for ubuntu-vg
/dev/mapper/mpatha <-- does not exist
/dev/mapper/ubuntu-vg (uses /dev/sda or /dev/sdb as the PV)
[ Proposed fix ]
* Since 25.10, we added support to multipath in the initramfs of the Ubuntu Server ISOs.
* This would correspond to a livecd-rootfs SRU along with a multipath-tools fix.
[ Test Plan ]
TODO
[ Where problems could occur? ]
* Bringing multipath support in the initramfs could slightly slow down the
boot process of the ISO. Nevertheless, 25.10 and 26.04 Ubuntu
Server ISOs have had multipath-support in the initramfs, and no measurable
slow down has been experienced.
[ Other Info ]
* For existing affected ISOs, there is a workaround:
1. open a shell in the installer environment (one can hit F2 in the
Subiquity TUI)
2. Delete the relevant VG using `dmsetup remove`:
$ sudo dmremove /dev/mapper/<vg>
3. Restart multipathd using:
$ sudo systemctl restart multipathd
4. Finally, restart Subiquity:
$ sudo snap restart subiquity
* Alternatively, users can wipe the affected disk and then restart he installer (but this involves manually erasing data from the disk).
[ Original description ]
== Comment: - Anushree Mathur ==
OS: 24.04 LTS (Noble Numbat)
I started the Ubuntu installation for 24.04 LTS (Noble Numbat) on L1(HOST) having SAN disk, it failed with the following error just after I chose the disk.
Ubuntu 24.04 LTS ubuntu-server hvc0
connecting...
waiting for cloud-init...
generating crash report
report saved to /var/crash/1724388235.797082424.ui.crash
Traceback (most recent call last):
File "/snap/subiquity/5745/lib/python3.10/site-packages/subiquity/client/controllers/filesystem.py", line 273, in _guided_choice
self.ui.set_body(FilesystemView(self.model, self))
File "/snap/subiquity/5745/lib/python3.10/site-packages/subiquity/ui/views/filesystem/filesystem.py", line 485, in __init__
self.refresh_model_inputs()
File "/snap/subiquity/5745/lib/python3.10/site-packages/subiquity/ui/views/filesystem/filesystem.py", line 540, in refresh_model_inputs
self.avail_list.refresh_model_inputs()
File "/snap/subiquity/5745/lib/python3.10/site-packages/subiquity/ui/views/filesystem/filesystem.py", line 417, in refresh_model_inputs
for obj, cells in summarize_device(device, filter):
File "/snap/subiquity/5745/lib/python3.10/site-packages/subiquity/ui/views/filesystem/helpers.py", line 32, in summarize_device
anns = labels.annotations(device) + labels.usage_labels(device)
File "/snap/subiquity/5745/usr/lib/python3.10/functools.py", line 889, in wrapper
return dispatch(args[0].__class__)(*args, **kw)
File "/snap/subiquity/5745/lib/python3.10/site-packages/subiquity/common/filesystem/labels.py", line 100, in _annotations_vg
member = next(iter(vg.devices))
StopIteration
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "/snap/subiquity/5745/usr/bin/subiquity", line 8, in <module>
sys.exit(main())
File "/snap/subiquity/5745/lib/python3.10/site-packages/subiquity/cmd/tui.py", line 158, in main
asyncio.run(run_with_loop())
File "/snap/subiquity/5745/usr/lib/python3.10/asyncio/runners.py", line 44, in run
return loop.run_until_complete(main)
File "/snap/subiquity/5745/usr/lib/python3.10/asyncio/base_events.py", line 649, in run_until_complete
return future.result()
File "/snap/subiquity/5745/lib/python3.10/site-packages/subiquity/cmd/tui.py", line 156, in run_with_loop
await subiquity_interface.run()
File "/snap/subiquity/5745/lib/python3.10/site-packages/subiquity/client/client.py", line 403, in run
await super().run()
File "/snap/subiquity/5745/lib/python3.10/site-packages/subiquitycore/tui.py", line 351, in run
await super().run()
File "/snap/subiquity/5745/lib/python3.10/site-packages/subiquitycore/core.py", line 134, in run
raise exc
RuntimeError: coroutine raised StopIteration
Ubuntu 24.04 LTS ubuntu-server hvc0
connecting...
ProblemType: Bug
Architecture: ppc64el
CrashDB: {'impl': 'launchpad', 'project': 'subiquity'}
I tried following 2 installation methods, it is failing in both the ways:
1) kexec method
2) attaching vdvd and starting installer
NOTE: It is happening only when the system has SAN disks otherwise this installation worked fine.
I will be attaching the crash report for this!
== Comment:- Hariharan T S ==
Verified the following cases.
Installation on Disk from VIOS - PASSED
Installatoin on Disk from VIOS and system had Disks from SAN - FAILED
Installation on Disk from SAN and system ahd Disk from VIOS - FAILED
== Comment:- Vaibhav Jain ==
Problem seems to happening when Subuquity enters the disk partition view. The system has a SAN disk and an existing Mullti Path DM volume on it.
Mirroring to distro
To manage notifications about this bug go to:
https://bugs.launchpad.net/subiquity/+bug/2080474/+subscriptions
More information about the foundations-bugs
mailing list