buffer cache flush

[Roshan Shetty]

Hi,

Is it safe to flush buffer cache on Centos to release the cache memory while Redis is running? Has anyone experienced any issues? We have 36 GB memory instance but most of the memory is consumed by caching and only about 5 Gb is used by Redis. I like to keep the system memory free as much as possible by periodically flushing buffer cache.

Thanks
Roshan

[Didier Spezia]

Hi,

it is generally safe to flush the filesystem cache, but it is not very useful ...

It tends to generate peaks of I/Os just after the cache has been flushed.

If your Redis instance does not generate I/Os, then it is not a problem.

Should the opposite occurs, you may impact the performance of the

foreground (AOF flushes), or background (BSSAVE or

BGREWRITEAOF) operations.

Regards,

Didier.