Freeradius checkval module

radiusd.conf:

…
…
checkval NAS_IP {
item-name = NAS-IP-Address
check-name = NAS-IP-Address
data-type = ipaddr
nofound-reject = no
}
…
…
authorize {
preprocess
…
…
sql_auth
NAS_IP
…
…
}

And then we need A/V Pair for each user like this:

test Auth-Type := Local, User-Password := 123321, NAS-IP-Address :=
1.2.3.4

Kernel vfs_cache_pressure

vfs_cache_pressure Controls the tendency of the kernel to reclaim the memory which is used for caching of directory and inode objects.

At the default value of vfs_cache_pressure = 100 the kernel will attempt to reclaim dentries and inodes at a “fair” rate with respect to pagecache and swapcache reclaim. Decreasing vfs_cache_pressure causes the kernel to prefer to retain dentry and inode caches. Increasing vfs_cache_pressure beyond 100 causes the kernel to prefer to reclaim dentries and inodes.