Xen on a second hard drive

Discussion in 'HOWTO-Related Questions' started by SirLancelot, Dec 3, 2008.

  1. SirLancelot

    SirLancelot New Member

    I've followed the guide at
    http://www.howtoforge.com/debian_etch_xen_from_debian_repository
    and this works perfectly.
    I am now installing on a new server. the hard discs on this server are as follows:-
    sda is a 250GB sata drive that I shall for now leave unpartitioned and will later be used as a mounted physical drive for one of the domU's.
    sdb is a scsi raid1 array that I shall use as the main install drive for xen and the domU images, with 2 partitions "/" and "swap".
    Installing debian then selecting (hd1) for grub works fine and the first disc (sda) is ignored by grub and the machine boots correctly. However after xen is installed the machine fails to boot with the message:-
    "ALERT! /dev/sdb1 does not exist. Dropping to shell!"
    Also none of the other boot options in the grub boot menu work. I am guessing that xen from the repository does not like to be installed on sdb and it is destroying the main partition.
    has anyone come accross this issue and is there a way to overcome this so that xen knows that it is being installed on a second hard drive?
    Many thanks in advance.
    Steve
     
  2. SirLancelot

    SirLancelot New Member

    After searching around it appears that this may be a bug causing the system to time out when trying to detect partitions on a raid or lvm at boot time. This does seem strange as I would have thought that during testing xen would have been tested on a raid set.
    Would anyone have any ideas for a fix for this, or am I looking in the wrong direction?
    Thanks
     
  3. SirLancelot

    SirLancelot New Member

    Update
    this error still persists but if I reboot several times the system will boot up correctly.
    There seems to be an issue with it timming out sometimes when trying to boot from a hardware RAID1 set. I can live with this for the moment as once configured it will remain up, with just the occasional reboot.
    If someone has an aswer for this it would be helpfull so i dont have to go into the server room and stand around and watch it boot up on the rack console.
    Many thanks.
     
  4. falko

    falko Super Moderator ISPConfig Developer

    What's in /boot/grub/menu.lst and /etc/fstab? What's the output of
    Code:
    fdisk -l
    ?

    Are there any errors in the output of
    Code:
    dmesg
    ?
     
  5. SirLancelot

    SirLancelot New Member

    Hi Falko,
    cheers for your assistance with this.


    /boot/grub/menu.lst is:-

    # menu.lst - See: grub(8), info grub, update-grub(8)
    # grub-install(8), grub-floppy(8),
    # grub-md5-crypt, /usr/share/doc/grub
    # and /usr/share/doc/grub-doc/.

    ## default num
    # Set the default entry to the entry number NUM. Numbering starts from 0, and
    # the entry number 0 is the default if the command is not used.
    #
    # You can specify 'saved' instead of a number. In this case, the default entry
    # is the entry saved with the command 'savedefault'.
    # WARNING: If you are using dmraid do not change this entry to 'saved' or your
    # array will desync and will not let you boot your system.
    default 0

    ## timeout sec
    # Set a timeout, in SEC seconds, before automatically booting the default entry
    # (normally the first entry defined).
    timeout 5

    # Pretty colours
    color cyan/blue white/blue

    title Xen 3.0.3-1-i386-pae / Debian GNU/Linux, kernel 2.6.18-6-xen-vserver-686
    root (hd1,0)
    kernel /boot/xen-3.0.3-1-i386-pae.gz
    module /boot/vmlinuz-2.6.18-6-xen-vserver-686 root=/dev/sdb1 ro console=tty0
    module /boot/initrd.img-2.6.18-6-xen-vserver-686
    savedefault

    title Debian GNU/Linux, kernel 2.6.18-6-486
    root (hd1,0)
    kernel /boot/vmlinuz-2.6.18-6-486 root=/dev/sdb1 ro
    initrd /boot/initrd.img-2.6.18-6-486
    savedefault

    title Debian GNU/Linux, kernel 2.6.18-6-486 (single-user mode)
    root (hd1,0)
    kernel /boot/vmlinuz-2.6.18-6-486 root=/dev/sdb1 ro single
    initrd /boot/initrd.img-2.6.18-6-486
    savedefault

    ### END DEBIAN AUTOMAGIC KERNELS LIST


    /etc/fstab is:-

    proc /proc proc defaults 0 0
    /dev/sdb1 / ext3 defaults,errors=remount-ro 0 1
    /dev/sdb5 none swap sw 0 0
    /dev/hda /media/cdrom0 udf,iso9660 user,noauto 0 0


    fdisk -l produces:-

    Disk /dev/sda: 250.0 GB, 250059350016 bytes
    255 heads, 63 sectors/track, 30401 cylinders
    Units = cylinders of 16065 * 512 = 8225280 bytes

    Device Boot Start End Blocks Id System
    /dev/sda1 1 30401 244196001 83 Linux

    Disk /dev/sdb: 18.2 GB, 18208260096 bytes
    255 heads, 63 sectors/track, 2213 cylinders
    Units = cylinders of 16065 * 512 = 8225280 bytes

    Device Boot Start End Blocks Id System
    /dev/sdb1 * 1 2115 16988706 83 Linux
    /dev/sdb2 2116 2213 787185 5 Extended
    /dev/sdb5 2116 2213 787153+ 82 Linux swap / Solaris

    I found the following errors when executing dmesg:-

    ACPI Error (psargs-0355): [Z00Q] Namespace lookup failure, AE_NOT_FOUND
    ACPI Error (psparse-0537): Method parse/execution failed [\_SB_.PCI0.ISA_.SIO_.COM1._STA] (Node c1b4e6a8), AE_NOT_FOUND
    ACPI Error (psargs-0355): [Z00Q] Namespace lookup failure, AE_NOT_FOUND
    ACPI Error (psparse-0537): Method parse/execution failed [\_SB_.PCI0.ISA_.SIO_.COM2._STA] (Node c1b4e5b8), AE_NOT_FOUND
    ACPI Error (psargs-0355): [Z00Q] Namespace lookup failure, AE_NOT_FOUND
    ACPI Error (psparse-0537): Method parse/execution failed [\_SB_.PCI0.ISA_.SIO_.LPT_._STA] (Node c1b4e478), AE_NOT_FOUND
    Linux Plug and Play Support v0.97 (c) Adam Belay
    pnp: PnP ACPI init
    ACPI Error (psargs-0355): [Z00Q] Namespace lookup failure, AE_NOT_FOUND
    ACPI Error (psparse-0537): Method parse/execution failed [\_SB_.PCI0.ISA_.SIO_.COM1._STA] (Node c1b4e6a8), AE_NOT_FOUND
    ACPI Error (psargs-0355): [Z00Q] Namespace lookup failure, AE_NOT_FOUND
    ACPI Error (psparse-0537): Method parse/execution failed [\_SB_.PCI0.ISA_.SIO_.COM2._STA] (Node c1b4e5b8), AE_NOT_FOUND
    ACPI Error (psargs-0355): [Z00Q] Namespace lookup failure, AE_NOT_FOUND
    ACPI Error (psparse-0537): Method parse/execution failed [\_SB_.PCI0.ISA_.SIO_.LPT_._STA] (Node c1b4e478), AE_NOT_FOUND
    pnp: PnP ACPI: found 10 devices
     
  6. jeffd

    jeffd New Member

    I've had this problem before on some dells, the installer would see the cdrom as /dev/sda and the first HD as /dev/sdb/ and I would have to edit the grub boot line and swtich out sdb with sda then make that change in /boot/grub/menu.lst and in /etc/fstab

    One thing you could do to fix this is to use UUIDs for your partions. When you get the system up run:
    Code:
    blkid
    This should give you a list of IDs and what partition they map to. You can then use that UUID in your /boot/grub/menu.lst in place of the /dev/sdxx like so:
    Code:
    title		Debian GNU/Linux, kernel 2.6.26-1-686-bigmem
    root		(hd0,0)
    kernel		/vmlinuz-2.6.26-1-686-bigmem root=UUID=84f7fcdb-1172-42aa-bf7e-8ba09d4c8efe ro quiet
    initrd		/initrd.img-2.6.26-1-686-bigmem
    
    
    Of course,use the UUID you get from the blkid commnad. You can use the same method in /etc/fstab as well.
     

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