1. On the UC you can not define a limit for one particular UC subscriber as such meaning that
it is not like that we can define that one particular subscriber will have a mailbox of
100 MB and some one else will have a mailbox of 5 MB. All the users will share
a mailbox store and in order to manage the disk space batter we can apply the Mailbox
Quotas and Message Aging Policy.
2. Assuming we have about 1500 subscriber then defining the Mailbox store for
"Maximum Size before Warning" to about 15 GB gives an average 100 MB of mailbox for each
user which is more than enough for many a environment. Please note that the total size of
the mailbox is dependent on the disk space available on the UC.
3. In most cases keeping the warning quota, send quota and send receive quota
to default and sufficient and this is a very optimum allocation of the mail boxes.
The disk space shown in the UC OS Admin Page is for that server only and it is not common to both pub and sub.
On all the Linux based CUCM and UC server you will observe the active and inactive partition
and it is not talking about the pub and sub. In a Linux based server all the updates/ES install/upgrades
go to an inactive partition and then you are required to do a 'switch version' and this is when the inactive partition
comes in to the picture.
Talking about the 'Mailbox Store Size', you can verify the mail box store
size from the CUC Admin Page > Message Storage > Mailbox Stores > Mailbox
(Default is UnityMbxDb1) > 'Maximum Size before Warning'. Now the maximum
size that you want Cisco Unity Connection to allow for this mailbox store.
If the mailbox store reaches 90 percent of this value, Connection logs a
warning in the system log. If the mailbox store reaches 100 percent of this
value, Connection logs an error in the system log and no point in time it
will stop accepting the messages until the disk space is completely full.
The mailbox store can keep on growing depending on the availability of the
free space available on the disk.
This 'Send/Receive Quota' for the UC Subscriber works a little differently.
In this case when a user is configured to use a particular amount of disk
space for voice mailbox quotas, and when the mailbox for that user reaches
the size specified in the Send/Receive Quota field, the user is prevented
from sending or receiving any more voice messages. Considering we have about
200 GB of disk space and about 1500 user I can safely suggest configuring
this limit to higher then defaulting as well (If desired). You might want to
consider the fact that 14 MB quota is about 215 minutes of recording using
G729 and about 30 minutes of recording using G711.
Also the 'Send/Receive Quotas' is a system wide parameter so the
configuration here applies to all the UC subscribers and this is not
configurable on per users basis.