Currently, We have 512m "JIRA_MAX_PERM_SIZE", Can we increase by 128mb more? Facing may performance issues now.
Yes you can, for further details regarding increasing memory I would like to point you towards the following documentation:
https://confluence.atlassian.com/display/JIRA/Increasing+JIRA+Memory
What should be max PERM size?
It looks like you're new here. Sign in or register to get started.