Most active segments
The filemon command can be used to create a report that lists the most active segments on the various layers of file system utilization, including the logical file system, virtual memory segments, LVM, and physical disk layers. This section describes the column headings displayed on the report.
- #MBs
- Total number of MBs transferred over measured interval for this segment. The rows are sorted by this field in decreasing order.
- #rpgs
- Number of 4-KB pages read into segment from disk.
- #wpgs
- Number of 4-KB pages written from segment to disk (page out).
- #segid
- VMM ID of memory segment.
- segtype
- Type of segment: working segment, persistent segment (local file), client segment (remote file), page table segment, system segment, or special persistent segments containing file system data (log, root directory, .inode, .inodemap, .inodex, .inodexmap, .indirect, .diskmap).
- volume:inode
- For persistent segments, name of logical volume that contains the associated file and the file's i-node number. This field can be used to associate a persistent segment with its corresponding file, shown in the Detailed File Stats reports. This field is blank for nonpersistent segments.
If the command is still active, the virtual memory analysis tool svmon can be used to display more information about a segment, given its segment ID (segid), as follows: svmon -D segid. See The svmon Command for a detailed discussion.
In our example, the segtype ??? means that the system cannot identify the segment type, and you must use the svmon command to get more information.