I want to increase the capacity of ISE's database utilization.

[CCC3]

I want to extend the storage period of the report.

I know you can extend the duration of the Data Retention Period to the settings of ise

but

You should also consider the capacity of the database utilization.

So, in order to increase the capacity of Database Utilization itself, do you just need to add the hard disk of ise?

[Arne Bier]

I assume you're using ISE VMs? You cannot resize the ISE VM hard drive - if you have a dedicated MNT node, then the advice would be to de-register that MNT, build a new VM with a larger hard disk and register it back into the Deployment. And do the same for the other MNT.

Are you hitting the capacity limit of your current MNT with the RADIUS/TACACS retention values?  The graphical bar graph is the best indicator of disk usage. Administration > System > Operational Data Purging

[CCC3]

I'm using 3755 appliance equipment, and I want to keep more reports
You need to check if you can physically add a separate hard disk.

[Arne Bier]

You can't add more disks to an SNS server because that would involve growing the RAID volume and then somehow telling ISE to expand the filesystems - which is not possible because we have no root access to the box. - and I don't believe that ISE uses a logical volume manager (LVM)- I'm 99.99% sure this is officially not supported by Cisco - you need to decide what disk options you want before you place the order for the appliance. According to the SNS datasheet, there are three disk types to choose from. 

I don't know if you would invalidate your Cisco Support if you installed extra drives, created a new RAID volume, and then re-installed the ISE operating system from scratch. In theory that should work, but I would check with Cisco first, to see if they support such a home brew solution.