I no longer have a shadow to test with but something like:
echo  "d tag^routine \n h" | csession [instance] -U %SYS
You need Unix passthough authentication to work.
Managing and Monitoring Shadowing might help you find the data you want

The affected class is not part of the required install for Cache 2018.1.5.659.0 or IRIS 2020.1.1.408.0.

I would search filesystems for JndiLookup and log4j.

The ^DATABASE routine in %SYS allows you to edit the size. Sizing a CACHE.DAT avoids the on the fly expansion that would otherwise happen. Some people thought this would be a performance benefit.

Looks like you can set charset to UTF-8 using the docs here. You might need the full version to do that.

What charset do you want to use? That may be the issue.

I use putty too.

Intersystems has worked hard but encryption is not free. Do you have something like batch processing? You would notice an impact more there then on a 1 second query. I would worry more about key security and recovery. Encryption also has a serious impact on the ability of modern SAN storage to dedup and compress which could result in higher than expected storage costs.

You might look at this tool combination for the last journal file.

Convert Journal Files Using ^JCONVERT and ^%JREAD

If you have not already, migrate to solid state disks.

It is weird that the page Vic recommends does not mention that.

Check Startup namespace for the user in ^SECURITY maybe.

Here is a link to the Cache document - https://docs.intersystems.com/latest/csp/docbook/DocBook.UI.Page.cls?KEY=GCDI_journal#GCDI_journal_view

Many things could be happening.

How do you cleanup journal files? Purge after so many backups? Are your backup working?

You could look in a journal file and see what global data is causing the expansion.

If you have the system management portal you can look at journal data there too.

You might need to go to the application vendor to tell what data a global holds.

Will Cache and other older version docs be put on here?

Roger is correct. I wonder if the error is controllable though through the cpf.

The rules on global names - linked to the temporary doc location -

http://dreamymclean.intersystems.skytapdns.com:52773/csp/docbook/Doc.View.cls?KEY=GGBL_structure

You could try to compact and truncate.

Dmitry's idea will also work and be faster.

I think the WRC would be the only ones who could tell you what could be moved into CACHETEMP unless you found someone else  who they had told already.

If you just don't want to store so many journals you could just backup multiple times a day and do a journal purge.

Congratulations on using Ensemble to the point you have this problem.

Yes, the instances interconnect and share files.