As our SDA1 drive is almost full, which files or folders can we clear to free up storage? I assume the 2 set of sub-folders can be safety removed from:

/opt/zimbra/zmstat/201*
/opt/zimbra/log/*.gz

Any other folders we can remove?

Reducing the HSM Policy to move older emails to SDA2 drive is very useful too. Is there other best practices to better manage our primary boot storage?