linux-vmstats

Retrieves memory and I/O load levels on a Linux system. Collects swap, memory, and block I/O related metrics from the /proc/meminfo and /proc/vmstat files.

Command properties

Item	Description
Command type	Driver query
Required permission	Administrator
License usage	Licensed command
Parallel execution	Not supported
Distributed execution	Runs on Data Node (mapper)

Syntax

linux-vmstats

Output fields

Field	Type	Description
`swap_size`	long	Total swap size (KiB)
`free_size`	long	Available memory size (KiB)
`buffer_size`	long	Buffer cache size (KiB)
`cache_size`	long	Page cache size (KiB)
`swap_in`	long	Number of pages swapped in per second
`swap_out`	long	Number of pages swapped out per second
`block_in`	long	Number of blocks read from block devices per second
`block_out`	long	Number of blocks written to block devices per second

Error codes

Parse errors

Error code	Message	Description
`95040`	no-read-permission	Occurs when a user without administrator privilege runs the command

Runtime errors

N/A

Description

The linux-vmstats command reads memory statistics (swap size, free memory, buffers, cache) from /proc/meminfo and I/O statistics (swap in/out, block in/out) from /proc/vmstat.

Swap I/O and block I/O metrics are calculated as the difference between two measurements taken 1 second apart, returning the per-second rate of change. Therefore, running this command incurs approximately 1 second of wait time. Memory-related metrics (swap size, free memory, buffers, cache) return the values from the second measurement point.

The output always contains exactly 1 record.

Examples

Retrieve memory and I/O statistics
```
linux-vmstats
```
Retrieves the current memory usage and I/O load levels of the system.
Check for swap activity
```
linux-vmstats
| search swap_in > 0 or swap_out > 0
```
Checks whether swap I/O occurred in the last second. Frequent swap activity may indicate low memory conditions.