The CallStash VM image includes a 30GB virtual disk containing a minimal Debian operating system and the CallStash operational software. This disk is sufficient to also contain the CallStash database. It is not however sufficient to store call recordings.

As part of your VM configuration before first boot you should attach an additional un-partitioned drive to the VM image. The size of this disk depends on the number of call recordings you expect to archive. As a rough calculation, CallStash archives approximately 1 second of recording in 8KB of disk space. So, for example:

• If you expect 500 calls per day, 5 days a week (52 x 5 days per year x 500 calls).
• With an average call duration of 4 minutes (240 seconds).
• And want to archive calls for 6 years.

This leads to a calculation of:

• 6 x (52 x 5 x 500 * 240) * 8000 bytes = (approximately) 1.6TB.

An approximation can be made by understanding that one hour of recorded audio uses about 30MB of storage.

Note these figures exclude operating system overhead. Unless you have accurate call histories it is advised that you err on the side of caution.

As stated, please ensure that this disk is attached to your VM configuration before first boot.

Note in addition to adding the additional drive, you will need to select the VM’s guest operating system before boot. This will need to be set to the latest Debian release your virtualisation software offers.