Cloned machine does not boot up properly
This document (3048119) is provided subject to the disclaimer at the end of this document.
Environment
SUSE Linux Enterprise Server 11
SUSE Linux Enterprise Server 10
SUSE Linux Enterprise Server 10
SUSE Linux Enterprise Server 9
SUSE Linux Enterprise Desktop 10Situation
- A virtual machine has been cloned, or
- a physical machine has been cloned onto identical hardware, or
- hardware (storage controller and/or network device) has been exchanged on a physical machine, or
- VMware tools have been installed into a VMware virtual machine.
- the root filesystem or other filesystems are not being found, or
- the network does not come up, or
- the network device names have changed.
Resolution
Disable the use of persistent network device names and of persistent storage device names prior to cloning or hardware change, or adjust device and interface names afterward.
Additional Information
Background: persistent device names
Please refer to the product documentation for in-depth background on persistent device names. In short, persistent device names provide stable names for network and storage devices, regardless of the order of recognition or the connection used for the device.
Related documentation
Disabling the use of persistent network device names (CODE11 products)
On CODE11 products like SUSE Linux Enterprise Server 11, the use of persistent network device names is disabled by clearing the /etc/udev/rules.d/70-persistent-net.rules file.
Clear the udev configuration for the network devices as follows:
Disabling the use of persistent network device names (CODE10 products)
On CODE10 products like SUSE Linux Enterprise Server 10, the use of persistent network device names is disabled in three steps.
Clear the udev configuration for the network devices.
Clear the udev configuration for the network devices as follows:
Rename the Ethernet configuration files
In order for the Ethernet configuration to come up on boot, the Ethernet
configuration has to be renamed.
Disabling the use of persistent network device names (CODE9 products)
On CODE9 products like SUSE Linux Enterprise Server 9, udev is not used, and is not as involved as in SLE 10. All that needs to be done is to rename the Ethernet configuration file.
Rename Ethernet configuration files
In order for the Ethernet configuration to come up on boot, the Ethernet configuration has to be renamed.
Disabling the use of persistent storage device names (CODE11, CODE10 and CODE9 products)
On CODE10 & 11 products like SUSE Linux Enterprise Server 10, the use of persistent names for storage devices is recommended in general. As of SLES10 SP1 it has been made the default for new installations. As with network devices, the use of persistent names for storage can cause problems when cloning machines though.
To disable the use of persistent storage device names, proceed as follows:
Network persistent device names
As of SLES 11 SP4 the behavior to disable persistent naming changed. In order to disable reboot persistent udev rules please create the following file with no content: /etc/udev/rules.d/75-persistent-net-generator.rules. This empty file overrides /lib/udev/rules.d/75-persistent-net-generator.rules and thus prevents the creation of udev rules for network devices, even if the file was deleted.
A different approach is to use the PCI BUS-IDs instead of the MAC address. This has the advantage in hardware environments, that defective NICs can be replaced without any change, else the network needs to get reconfigured. This can be done in YaST2:
Steps to perform in case hardware has been exchanged on a physical machine (Disaster Recovery)
In case hardware like storage,network device and/or motherboards with integrated devices has been exchanged on a physical machine, the above steps need to be performed from the SuSE Rescue System. Proceed as follows:
Please refer to the product documentation for in-depth background on persistent device names. In short, persistent device names provide stable names for network and storage devices, regardless of the order of recognition or the connection used for the device.
Related documentation
Disabling the use of persistent network device names (CODE11 products)
On CODE11 products like SUSE Linux Enterprise Server 11, the use of persistent network device names is disabled by clearing the /etc/udev/rules.d/70-persistent-net.rules file.
Clear the udev configuration for the network devices as follows:
cat< /dev/null > /etc/udev/rules.d/70-persistent-net.rules
Disabling the use of persistent network device names (CODE10 products)
On CODE10 products like SUSE Linux Enterprise Server 10, the use of persistent network device names is disabled in three steps.
Clear the udev configuration for the network devices.
Clear the udev configuration for the network devices as follows:
cat< /dev/null > /etc/udev/rules.d/30-net_persistent_names.rules
Rename the Ethernet configuration files
In order for the Ethernet configuration to come up on boot, the Ethernet
configuration has to be renamed.
- Go to /etc/sysconfig/network
- Find the ifcfg-eth... file for each Ethernet device (the trailing identifier is the MAC address for the device), for example: ifcfg-eth-id-00:AA:BB:11:22:33
- Rename the file to ifcfg-ethX. For example, to have the configuration
for eth0 the name would be: ifcfg-eth0
- Open /etc/sysconfig/network/config for editing
- Find the line reading:
FORCE_PERSISTENT_NAMES="yes" - Change it to:
FORCE_PERSISTENT_NAMES="no" - Save
- Reboot
Disabling the use of persistent network device names (CODE9 products)
On CODE9 products like SUSE Linux Enterprise Server 9, udev is not used, and is not as involved as in SLE 10. All that needs to be done is to rename the Ethernet configuration file.
Rename Ethernet configuration files
In order for the Ethernet configuration to come up on boot, the Ethernet configuration has to be renamed.
- Go to /etc/sysconfig/network
- Find the ifcfg-eth... file for each Ethernet device (the trailing identifier is the MAC address for the device), for example: ifcfg-eth-id-00:AA:BB:11:22:33
- Rename the file to ifcfg-ethX. For example, to have the configuration for eth0 the name would be:ifcfg-eth0.
Disabling the use of persistent storage device names (CODE11, CODE10 and CODE9 products)
On CODE10 & 11 products like SUSE Linux Enterprise Server 10, the use of persistent names for storage devices is recommended in general. As of SLES10 SP1 it has been made the default for new installations. As with network devices, the use of persistent names for storage can cause problems when cloning machines though.
To disable the use of persistent storage device names, proceed as follows:
- Examine the boot loader configuration file /boot/grub/menu.lst and the filesystem table /etc/fstab for the presence of /dev/disk/by-* references.
- Store the mapping of /dev/disk/by-* symlinks to their targets in a scratch file:
ls -l /dev/disk/by-* > /tmp/scratchpad.txt
- Remove all entries that involve storage that is not local to the system (such as SAN or iSCSI volumes) from the scratch file.
- Edit /boot/grub/menu.lst and/etc/fstab, replacing the /dev/disk/by-* entries in them which occur in the scratch file by the device names the symlinks point to.
- Reboot the system and verify that it comes up cleanly.
Network persistent device names
As of SLES 11 SP4 the behavior to disable persistent naming changed. In order to disable reboot persistent udev rules please create the following file with no content: /etc/udev/rules.d/75-persistent-net-generator.rules. This empty file overrides /lib/udev/rules.d/75-persistent-net-generator.rules and thus prevents the creation of udev rules for network devices, even if the file was deleted.
A different approach is to use the PCI BUS-IDs instead of the MAC address. This has the advantage in hardware environments, that defective NICs can be replaced without any change, else the network needs to get reconfigured. This can be done in YaST2:
- start yast2 lan
- select the NIC and press edit
- click on the hardware tab
- select change to edit the udev rules
- change from MAC address to BUS ID for the selected ethernet device
- save the changes and exit YaST2
Steps to perform in case hardware has been exchanged on a physical machine (Disaster Recovery)
In case hardware like storage,network device and/or motherboards with integrated devices has been exchanged on a physical machine, the above steps need to be performed from the SuSE Rescue System. Proceed as follows:
- Boot off the Installation CD/DVD and choose "Rescue System"
- Mount the system partition and perform a chroot, as described in TID 000016032 - How to access LVM partitions when system is booted with rescue CD.
- To disable the use of persistent network and storage device names perform the steps as described in the respective sections above.
- Exit from chroot (CTRL-D or "exit").
- Umount the system partition.
- Reboot the server.
Disclaimer
This Support Knowledgebase provides a valuable tool for SUSE customers and parties interested in our products and solutions to acquire information, ideas and learn from one another. Materials are provided for informational, personal or non-commercial use within your organization and are presented "AS IS" WITHOUT WARRANTY OF ANY KIND.
- Document ID:3048119
- Creation Date: 08-Jan-2008
- Modified Date:23-Feb-2021
-
- SUSE Linux Enterprise Desktop
- SUSE Linux Enterprise Server
- SUSE Linux Enterprise Real Time Extension
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