Hi, I cannot successfully move the backing file of a COW file. I am following the instructions for moving the backing file given at:
http://user-mode-linux.sourceforge.net/shared_fs.html e.g. I had /somewhere/root_fs /somewhere/root_fs_cow starting um with: ./linux ubd0=/somewhere/root_fs_cow,/somewhere/root_fs all works fine Now move the root_fs mv /somewhere/root_fs /new/root_fs now start um: ./linux ubd0=/somewhere/root_fs_cow,/new/root_fs .... Couldn't stat '/somewhere/root_fs', err = 2 Couldn't stat "/somewhere/root_fs" : err = 2 Failed to get modification time of backing file "/somewhere/root_fs", err = 2 Failed to open '/somewhere/root_fs_cow', errno = 2 VFS: Cannot open root device "98:0" or unknown-block(98,0) Please append a correct "root=" boot option Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(98,0) I checked that the root_fs system was not corrupted by reverting to the original location cp -a /new/root_fs /somewhere/root_fs Now it works again using the first um invocation showing that the move itself was not a problem. The documentation implies that starting um with the new backing file location updates the original COW file: "UML will notice the mismatch between the command line and COW header, check the size and mtime of the new backing file path, and update the COW header to reflect it if it checks out." Can anyone report if this actually works: I am using a gentoo 2005.1 system with: 2.6.12-gentoo-r6-skas3-v8.2 host kernel UM kernel is the same source tree (gentoo patched 2.6.12) usermode-utilities-20040406 Martin -- Dr. M.J. Reed Room: 1NW.5.3G Dept. Electronic Systems Engineering Tel:+44 (0)1206 872479 University of Essex, Colchester CO4 3SQ, UK FAX:+44 (0)1206 872900 Email mjreed (non Essex users should add @essex.ac.uk) Web: http://esewww.essex.ac.uk/~mjreed ------------------------------------------------------- SF.Net email is sponsored by: Tame your development challenges with Apache's Geronimo App Server. Download it for free - -and be entered to win a 42" plasma tv or your very own Sony(tm)PSP. Click here to play: http://sourceforge.net/geronimo.php _______________________________________________ User-mode-linux-user mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/user-mode-linux-user
