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Check path-rw-test

Overview

Tests if a path is writable and readable by creating, writing, reading, and deleting a temporary file. Especially useful for mounted filesystems such as NFS or SMB where the mount may silently become read-only or unresponsive. The local temporary directory is always tested as a baseline. Alerts if the path is not writable or readable.

Data Collection:

  • May require root or sudo depending on the paths being tested

  • By design this check creates, writes, reads and deletes a probe file in whatever directory it is pointed at, with root privileges when run via sudo. That is inherent to its purpose, so the path cannot be confined to a fixed directory: anyone who can invoke the check through sudo can test write access anywhere on the system. Securing that capability is the operator's responsibility. Restrict the permitted arguments in your sudoers entry if your threat model requires it.

  • Creates a temporary file in each specified path (and always in the system's temp directory)

  • Writes a test string, reads it back, then deletes the temporary file
  • Reports which paths failed and which were tested

Fact Sheet

Fact Value
Check Plugin Download https://github.com/Linuxfabrik/monitoring-plugins/tree/main/check-plugins/path-rw-test
Nagios/Icinga Check Name check_path_rw_test
Check Interval Recommendation Every minute
Can be called without parameters Yes
Runs on Cross-platform
Compiled for Windows Yes

Help

usage: path-rw-test [-h] [-V] [--always-ok] [--path PATH]
                    [--severity {warn,crit}]

Tests if a path is writable and readable by creating, writing, reading, and
deleting a temporary file. Especially useful for mounted filesystems such as
NFS or SMB where the mount may silently become read-only or unresponsive. The
local temporary directory is always tested as a baseline. Alerts if the path
is not writable or readable. Requires root or sudo.

options:
  -h, --help            show this help message and exit
  -V, --version         show program's version number and exit
  --always-ok           Always returns OK.
  --path PATH           Path to test for read/write access by creating and
                        deleting a temporary file. Can be specified multiple
                        times. Default: ['/tmp']
  --severity {warn,crit}
                        Severity for alerting. Default: warn

Documentation:
https://linuxfabrik.github.io/monitoring-plugins/check-plugins/path-rw-test/

Usage Examples

./path-rw-test --path /mnt/nfs --path /mnt/smb --path /usr --severity warn

Output:

Error creating/writing/reading/deleting file in `/usr` ([Errno 13] Permission denied: '/usr/tmptbt8daho'). Tested: /tmp, /mnt/nfs, /mnt/smb, /usr

States

  • OK if all paths are writable and readable.
  • WARN if --severity is set to warn (default) and any path fails the read/write test.
  • CRIT if --severity is set to crit and any path fails the read/write test.
  • --always-ok suppresses all alerts and always returns OK.

Perfdata / Metrics

There is no perfdata.

Credits, License