When it becomes handy to disable NFS attribute caching

https://docstore.mik.ua/orelly/networking_2ndEd/nfs/ch18_06.htm

If changes made by one client need to be reflected on other clients with finer granularity, the attribute cache lifetime can be reduced to one second using the actimeo option, which sets both the regular file and directory minimum and maximum lifetimes to the same value:

> mount -t nfs -o actimeo=1 server:/export /mnt

This has the same effect as:

> mount -t nfs -o acregmin=1,acregmax=1,acdirmin=1,acdirmax=1 \ server:/export /mnt

To disable the caching completely:

> mount -t nfs -o actimeo=0 server:/export /mnt