tmpfs is a temporary filesystem that resides in memory and/or your swap partition(s), depending on how much you fill it up. Mounting directories as tmpfs can be an effective way of speeding up accesses to their files, or to ensure that their contents are automatically cleared upon reboot.

By default, a tmpfs partition has its maximum size set to half your total RAM, but this can be customized. Note that the actual memory/swap consumption depends on how much you fill it up, as tmpfs partitions do not consume any memory until it is actually needed.
To explicitly set a maximum size, in this example to override the default /tmp mount, use the size mount option:

tmpfs /tmp tmpfs nodev,nosuid,size=4G 0 0

The tmpfs can also be temporarily resized without the need to reboot:

root# mount -o remount,size=6G,noatime /tmp

To find a filesystem at /proc/mounts of /tmp use findmnt which will list all mounted filesytems or search for a filesystem. The findmnt command is able to search in /etc/fstab, /etc/fstab.d, /etc/mtab or /proc/self/mountinfo. If device or mountpoint is not given, all filesystems are shown.

root# findmnt --target /tmp
/tmp tmpfs tmpfs rw,nosuid,nodev,relatime

Download and install Perl modules.

Debian – download and install from CPAN

root~# dh-make-perl --install --cpan Foo::Bar

Linux – download and install from CPAN

root~# perl -MCPAN -e shell
cpan> install Foo::Bar

For example:

DBI is a database-independent interface for the Perl programming language. DBD::mysql is the driver for connecting to MySQL database servers with DBI.
DBI is the basic abstraction layer for working with databases in Perl.
DBD::mysql is the driver for using MySQL with DBI.
Net::MySQL is a pure-Perl implementation of the MySQL client-server protocol. (It is not necessary when using DBI with DBD::mysql, but may be useful in environments where you are not able to compile the MySQL client library required by DBD::mysql.)

root~# perl -MCPAN -e shell
cpan> install DBI
cpan> install DBD::mysql
cpan> install Net::MySQL


root~# cpan -f DBI
root~# cpan -f DBD::mysql
root~# cpan -f Net:MySQL

Where -f stands for: Forces the specified action, when it normally would have failed.
Most of the time I had used cpan -f 😉