GPFS command

For performance reasons, GPFS™ logging allows the condition where disk blocks are marked used but not actually part of a file after a node failure. The online version of mmfsck cleans up that condition. Runningmmfsck -o -n scans the file system to determine if correction might be useful. The online version of mmfsck runs on the file system manager and scans all inodes and indirect blocks looking for disk blocks that are allocated but not used. If authorized to repair the file system, it releases the blocks. If not authorized to repair the file system, it reports the condition to standard output on the invoking node.

The offline version of mmfsck is the last line of defense for a file system that cannot be used. It will most often be needed in the case where GPFS recovery logs are not available because of disk media failures. Themmfsck command runs on the file system manager and reports status to the invoking node. It is mutually incompatible with any other use of the file system and checks for any running commands or any nodes with the file system mounted. It exits if any are found. It also exits if any disks are down and require the use of mmchdisk to change them to upor recovering. The mmfsck command performs a full file system scan looking for metadata inconsistencies. This process can be lengthy on large file systems. It seeks permission from the user to repair any problems that are found, which may result in the removal of files or directories that are corrupt. The processing of this command is similar to those for other file systems.