subject: Force Leave Operation With Cman_tool Command Cause Data Loss In Linux [print this page] In Linux operating system-based computer, the Cluster Management tool or Cluster Manager is used to manage the user nodes. This is a command-line or GUI tool, which works on one or multiple cluster nodes. It works together with the cluster management agent. It has various subsystems and CMAN is one of them. To manage the cluster management subsystem CMAN, cman_tool program is used. But in case if you use incorrect command or switch with this utility, all cluster nodes may get affected and data loss situations arise. In order to retrieve data in these circumstances, Linux Data Recovery solutions are required.
The cman_tool could be used for joining the nodes to cluster, kill another cluster node, change value of the expected votes of cluster, and leave the cluster. You should be careful while using this application and must understand the consequences of commands issued through cman_tool. They might affect all the nodes in cluster. In most of the cases, this program is invoked by the shutdown and startup scripts. The cman_tool uses various subcommands, which
include the following:
Join- It is the major use of the cman_tool. This utility instructs cluster manager to try to join the existing cluster or form a new cluster (if there is not existing cluster). If you do not give any option to the command, it would take cluster configuration information from Cluster Configuration System (CCS).
Kill- Tells the CMAN to kill another node in cluster. It would cause local node to send KILL message to the node and it would shut down. If the node had failed, recovery would occur.
Leave- Tells the CMAN to leave cluster. You can't do it if the subsystems (like GFS and DLM) are active. You need to shutdown CLVM and dismount all the GFS file systems before using the cman_tool leave. Before applying the force command with this option, you should create backup of all your valuable data as it might cause critical data loss situations and need Data Recovery Linux to handle it.
Linux Recovery is potential through powerful third-party applications, known as Linux Data Recovery software. They use extensive scanning techniques to thoroughly scan whole hard drive and extract all of your valuable data in most of the data loss situations. They have simple graphical user interface and thus do not need sound technical skills to retrieve data.
Stellar Phoenix Linux Data Recovery is an effective tool to ensure absolute recovery in the majority of data loss situations. It supports recovery from Ext4,Ext3, Ext2, FAT32, FAT16 and FAT12 file system volumes. The software works well with all major distributions of Linux including SUSE, Red Hat, Mandriva and Ubuntu.
