Ah, no I think this might be along right lines: udev is calling blkid on the _partition_ of course, so it can probe for filesystem etc without looking at the partition table. After it's done that, it does look for the partition table so it can read the ID_PART_ENTRY_* values from it, but if it fails to load the partition table it just gives up and still returns success.
As to how this might happen, well there are certainly moments during sgdisk's writing of the partition table when the gpt data is not completely consistent (it contains checksums and is not written atomically). Two things are still a bit unsatisfactory about this explanation though: 1) it's a mighty tight race, hitting this with any regularity borders on the incredible and 2) I have no idea why this only occurs on Azure on Cosmic up. Although I guess 1) may explain 2) I suppose. Setting LIBBLKID_DEBUG=lowprobe in systemd-udevd's environment during a failing boot would be very interesting to confirm or deny this line of reasoning -- although this will make udevd produce gobs of output and possibly disturb any race. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux-azure in Ubuntu. https://bugs.launchpad.net/bugs/1834875 Title: cloud-init growpart race with udev Status in cloud-init: Incomplete Status in cloud-utils: New Status in linux-azure package in Ubuntu: New Status in systemd package in Ubuntu: Incomplete Bug description: On Azure, it happens regularly (20-30%), that cloud-init's growpart module fails to extend the partition to full size. Such as in this example: ======================================== 2019-06-28 12:24:18,666 - util.py[DEBUG]: Running command ['growpart', '--dry-run', '/dev/sda', '1'] with allowed return codes [0] (shell=False, capture=True) 2019-06-28 12:24:19,157 - util.py[DEBUG]: Running command ['growpart', '/dev/sda', '1'] with allowed return codes [0] (shell=False, capture=True) 2019-06-28 12:24:19,726 - util.py[DEBUG]: resize_devices took 1.075 seconds 2019-06-28 12:24:19,726 - handlers.py[DEBUG]: finish: init-network/config-growpart: FAIL: running config-growpart with frequency always 2019-06-28 12:24:19,727 - util.py[WARNING]: Running module growpart (<module 'cloudinit.config.cc_growpart' from '/usr/lib/python3/dist-packages/cloudinit/config/cc_growpart.py'>) failed 2019-06-28 12:24:19,727 - util.py[DEBUG]: Running module growpart (<module 'cloudinit.config.cc_growpart' from '/usr/lib/python3/dist-packages/cloudinit/config/cc_growpart.py'>) failed Traceback (most recent call last): File "/usr/lib/python3/dist-packages/cloudinit/stages.py", line 812, in _run_modules freq=freq) File "/usr/lib/python3/dist-packages/cloudinit/cloud.py", line 54, in run return self._runners.run(name, functor, args, freq, clear_on_fail) File "/usr/lib/python3/dist-packages/cloudinit/helpers.py", line 187, in run results = functor(*args) File "/usr/lib/python3/dist-packages/cloudinit/config/cc_growpart.py", line 351, in handle func=resize_devices, args=(resizer, devices)) File "/usr/lib/python3/dist-packages/cloudinit/util.py", line 2521, in log_time ret = func(*args, **kwargs) File "/usr/lib/python3/dist-packages/cloudinit/config/cc_growpart.py", line 298, in resize_devices (old, new) = resizer.resize(disk, ptnum, blockdev) File "/usr/lib/python3/dist-packages/cloudinit/config/cc_growpart.py", line 159, in resize return (before, get_size(partdev)) File "/usr/lib/python3/dist-packages/cloudinit/config/cc_growpart.py", line 198, in get_size fd = os.open(filename, os.O_RDONLY) FileNotFoundError: [Errno 2] No such file or directory: '/dev/disk/by-partuuid/a5f2b49f-abd6-427f-bbc4-ba5559235cf3' ======================================== @rcj suggested this is a race with udev. This seems to only happen on Cosmic and later. To manage notifications about this bug go to: https://bugs.launchpad.net/cloud-init/+bug/1834875/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
