casper: showmounts show-cow boot parameters do not work (casper-snapshot)

[a1bert]

lsb_release -rd
Description: Ubuntu 20.04 LTS
Release: 20.04
(custom debootstrap created filesystem.squashfs)

apt-cache policy casper
casper:
  Installed: 1.445
  Candidate: 1.445
  Version table:
 *** 1.445 100
        100 /var/lib/dpkg/status

casper-snapshot is not working because /cow is not exposed when using showmounts|show-cow boot parameters

there is no /cow directory on rootmnt when trying to move /cow:

   # move /cow such that live-system can poke & debug the overlayfs layers
    mount -o move /cow "${rootmnt}/cow"

error in casper.log:

mount: mounting /cow on /root/cow failed: No such file or directory

casper-snapshot:

Error: /cow is not a directory

FIX: create ${rootmnt}/cow dir before moving:

   # move /cow such that live-system can poke & debug the overlayfs layers
   mkdir -p "${rootmnt}/cow"
   mount -o move /cow "${rootmnt}/cow"

[Michael Hudson-Doyle (mwhudson)]

Thanks for submitting the MR! Hopefully I or someone else can review it soon.

[Matthew Wilker (mwilker)]

FYI, I'm the person who submitted the MR, but I'm not the person who submitted either this bug or the other one #1931027, which is a duplicate. I marked this bug as a duplicate of the other one because the other one's gotten slightly more attention; let me know if you have any problems or concerns.