When updating my XenServer virtual machines I got a strange error message:
s0102:/# apt-get update Get:1 http://security.debian.org lenny/updates Release.gpg [835B] Hit http://ftp.de.debian.org lenny Release.gpg Get:2 http://security.debian.org lenny/updates Release [40.8kB] Hit http://ftp.de.debian.org lenny Release Get:3 http://volatile.debian.org lenny/volatile Release.gpg [189B] Get:4 http://volatile.debian.org lenny/volatile Release [40.7kB] Get:5 http://updates.vmd.citrix.com lenny Release.gpg [197B] Ign http://security.debian.org lenny/updates/main Packages/DiffIndex Ign http://ftp.de.debian.org lenny/main Packages/DiffIndex Ign http://security.debian.org lenny/updates/main Sources/DiffIndex Get:6 http://security.debian.org lenny/updates/main Packages [320kB] Ign http://ftp.de.debian.org lenny/main Sources/DiffIndex Get:7 http://updates.vmd.citrix.com lenny Release [1630B] Hit http://ftp.de.debian.org lenny/main Packages Hit http://ftp.de.debian.org lenny/main Sources Ign http://updates.vmd.citrix.com lenny/main Packages/DiffIndex Get:8 http://security.debian.org lenny/updates/main Sources [81.2kB] Ign http://volatile.debian.org lenny/volatile/main Packages/DiffIndex Ign http://volatile.debian.org lenny/volatile/main Sources/DiffIndex Ign http://updates.vmd.citrix.com lenny/main Sources/DiffIndex Get:9 http://volatile.debian.org lenny/volatile/main Packages [7541B] Get:10 http://updates.vmd.citrix.com lenny/main Packages [2151B] Get:11 http://volatile.debian.org lenny/volatile/main Sources [2237B] Get:12 http://updates.vmd.citrix.com lenny/main Sources [294B] Fetched 498kB in 2s (191kB/s) Reading package lists... Done s0102:/var/tmp# apt-get upgrade Reading package lists... Done Building dependency tree Reading state information... Done The following packages have been kept back: linux-image-2.6-xen 0 upgraded, 0 newly installed, 0 to remove and 1 not upgraded. s0102:/#
The reason for this Debian error message is that there is some inconsistency in the Debian package build. The package linux-image-2.6-xen depends on another package which is not installed. As this problem exists on all of ym XenServer virtual machines, it is unlikely that this was caused by some mistake on my side, so I think it is a problem of the package on the Citrix package server.
Anyway, it is easy to fix. Just run apt-get dist-upgrade:
s0102:/# apt-get dist-upgrade Reading package lists... Done Building dependency tree Reading state information... Done Calculating upgrade... Done The following NEW packages will be installed: linux-image-2.6.29-xs5.5.0.17 The following packages will be upgraded: linux-image-2.6-xen 1 upgraded, 1 newly installed, 0 to remove and 0 not upgraded. Need to get 23.5MB of archives. After this operation, 69.8MB of additional disk space will be used. Do you want to continue [Y/n]? y Get:1 http://updates.vmd.citrix.com lenny/main linux-image-2.6.29-xs5.5.0.17 170 [23.5MB] Get:2 http://updates.vmd.citrix.com lenny/main linux-image-2.6-xen 2.6.29-xs5.5.0.17 [668B] Fetched 23.5MB in 47s (494kB/s) Preconfiguring packages ... Selecting previously deselected package linux-image-2.6.29-xs5.5.0.17. (Reading database ... 16794 files and directories currently installed.) Unpacking linux-image-2.6.29-xs5.5.0.17 (from .../linux-image-2.6.29-xs5.5.0.17_170_i386.deb) ... Done. Preparing to replace linux-image-2.6-xen 2.6.29-xs5.5.0.14 (using .../linux-image-2.6-xen_2.6.29-xs5.5.0.17_i386.deb) ... Unpacking replacement linux-image-2.6-xen ... Setting up linux-image-2.6.29-xs5.5.0.17 (170) ... Hmm. There is a symbolic link /lib/modules/2.6.29-xs5.5.0.17/build However, I can not read it: No such file or directory Therefore, I am deleting /lib/modules/2.6.29-xs5.5.0.17/build Hmm. The package shipped with a symbolic link /lib/modules/2.6.29-xs5.5.0.17/source However, I can not read the target: No such file or directory Therefore, I am deleting /lib/modules/2.6.29-xs5.5.0.17/source Running depmod. Finding valid ramdisk creators. Using mkinitramfs-kpkg to build the ramdisk. Running postinst hook script update-grub. Searching for GRUB installation directory ... found: /boot/grub Searching for default file ... found: /boot/grub/default Testing for an existing GRUB menu.lst file ... found: /boot/grub/menu.lst Searching for splash image ... none found, skipping ... Found kernel: /vmlinuz-2.6.29-xs5.5.0.17 Found kernel: /vmlinuz-2.6.29-xs5.5.0.14 Found kernel: /vmlinuz-2.6.26-2-686-bigmem Updating /boot/grub/menu.lst ... done Setting up linux-image-2.6-xen (2.6.29-xs5.5.0.17) ... s0102:/#
The new kernel vmlinuz-2.6.29-xs5.5.0.17 has been installed.
While we are at it, we could as well delete the old kernels as they are no longer in use and recover a few MByte of disk space.
s0102:/# apt-get purge linux-image-2.6-686-bigmem linux-image-2.6.26-2-686-bigmem linux-image-2.6.29-xs5.5.0.14 Reading package lists... Done Building dependency tree Reading state information... Done The following packages will be REMOVED: linux-image-2.6-686-bigmem* linux-image-2.6.26-2-686-bigmem* linux-image-2.6.29-xs5.5.0.14* 0 upgraded, 0 newly installed, 3 to remove and 0 not upgraded. After this operation, 69.5MB disk space will be freed. Do you want to continue [Y/n]? y (Reading database ... 19714 files and directories currently installed.) Removing linux-image-2.6-686-bigmem ... Removing linux-image-2.6.26-2-686-bigmem ... Running postrm hook script /sbin/update-grub. Searching for GRUB installation directory ... found: /boot/grub Searching for default file ... found: /boot/grub/default Testing for an existing GRUB menu.lst file ... found: /boot/grub/menu.lst Searching for splash image ... none found, skipping ... Found kernel: /vmlinuz-2.6.29-xs5.5.0.17 Found kernel: /vmlinuz-2.6.29-xs5.5.0.14 Updating /boot/grub/menu.lst ... done Purging configuration files for linux-image-2.6.26-2-686-bigmem ... Running postrm hook script /sbin/update-grub. Searching for GRUB installation directory ... found: /boot/grub Searching for default file ... found: /boot/grub/default Testing for an existing GRUB menu.lst file ... found: /boot/grub/menu.lst Searching for splash image ... none found, skipping ... Found kernel: /vmlinuz-2.6.29-xs5.5.0.17 Found kernel: /vmlinuz-2.6.29-xs5.5.0.14 Updating /boot/grub/menu.lst ... done Removing linux-image-2.6.29-xs5.5.0.14 ... Ok, proceeding with removing running kernel image. Running postrm hook script /sbin/update-grub. Searching for GRUB installation directory ... found: /boot/grub Searching for default file ... found: /boot/grub/default Testing for an existing GRUB menu.lst file ... found: /boot/grub/menu.lst Searching for splash image ... none found, skipping ... Found kernel: /vmlinuz-2.6.29-xs5.5.0.17 Updating /boot/grub/menu.lst ... done The link /vmlinuz.old is a damaged link Removing symbolic link vmlinuz.old Unless you used the optional flag in lilo, you may need to re-run your boot loader[lilo] The link /initrd.img.old is a damaged link Removing symbolic link initrd.img.old Unless you used the optional flag in lilo, you may need to re-run your boot loader[lilo] Purging configuration files for linux-image-2.6.29-xs5.5.0.14 ... Running postrm hook script /sbin/update-grub. Searching for GRUB installation directory ... found: /boot/grub Searching for default file ... found: /boot/grub/default Testing for an existing GRUB menu.lst file ... found: /boot/grub/menu.lst Searching for splash image ... none found, skipping ... Found kernel: /vmlinuz-2.6.29-xs5.5.0.17 Updating /boot/grub/menu.lst ... done s0102:/#
During delete a warning is displayed informing that we are about to delete a running kernel and whether would like to cancel the operation. In this case, it is ok to answer this with "No".
Before we reboot, we should check the /boot/grub/menu.lst file whether it contains a reference to the new installed kernel. If not, we will not be able to boot.
The last lines of /boot/grub/menu.lst should look like this:
## ## End Default Options ## title Debian GNU/Linux, kernel 2.6.29-xs5.5.0.17 root (hd0,0) kernel /vmlinuz-2.6.29-xs5.5.0.17 root=/dev/mapper/dsk-root ro console=hvc0 quiet initrd /initrd.img-2.6.29-xs5.5.0.17 title Debian GNU/Linux, kernel 2.6.29-xs5.5.0.17 (single-user mode) root (hd0,0) kernel /vmlinuz-2.6.29-xs5.5.0.17 root=/dev/mapper/dsk-root ro console=hvc0 single initrd /initrd.img-2.6.29-xs5.5.0.17 ### END DEBIAN AUTOMAGIC KERNELS LIST