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sys-cmd memory drop-page-cache
sys-cmd memory drop-page-cache first makes the pending disk writes complete in WEB-CLI, and then empties the page cache that the system keeps in memory to speed up disk access. It does not touch the application data; the area that is freed passes from the buff/cache column to the free column.
Command Summary
admin@TR7LBWAF01> sys-cmd memory drop-page-cache
⚠ You are about to drop the page cache
This will clear the page cache. A temporary performance degradation may occur.
Type "yes" to confirm: yes
Page cache dropped successfully.
admin@TR7LBWAF01>
The command has no field or parameter. When it is run, the confirmation screen opens; when evet is written in the Turkish interface and yes in the English interface, the operation is applied. If anything else is written, the Invalid confirmation. Operation cancelled. message appears; Esc closes the confirmation screen.
How It Works
| Subject | Behavior |
|---|---|
| Context | It is not affected by the selected v-device and route table; it always runs on the device itself. |
| Effect | The files read from the cache are read from the disk again for a while; during this time disk access may slow down. |
| The result message | When the work finishes, Page cache dropped successfully. is written. This message is written without looking at the exit status of the operation; if there is a red line above it, the operation may not have been completed. |
| Recording | Every run is written to the user logs. |
When Is It Used?
The page cache is not a problem under normal conditions and it shrinks by itself when memory is needed. This command is used to reset the cache before a measurement or a test, or to see that the buff/cache area can really be given back.
admin@TR7LBWAF01> sys-cmd memory status
admin@TR7LBWAF01> sys-cmd memory drop-page-cache
admin@TR7LBWAF01> sys-cmd memory status
admin@TR7LBWAF01>
Things to Know
- It is not a permanent solution. The cache fills up again in a short time; a continuous memory shortage is solved not with this command but with resource planning.
- For a more comprehensive cleanup
memory drop-all-cachesis used; its performance effect is more noticeable.
