You can remove it to reclaim your disk space. It won’t hurt CIS.
Update and final post here (I hope)
Currently on build 12.2.2.7098 and the cmddata file is back to a reasonable 192MB
A big ‘thank you’ to the Comodo team and forum staff
There is an entry in this thread that says the size of cmddata is going to be limited in a future release. That either hasn’t happened or the change is not doing anything to reduce the size of files which are excessive.
The limitation has not happened (yet).
Hi all,
A Comodo Firewall file (cmddata) takes up 60 GB of space. Can you tell me what the purpose of the file is?
It is not supposed to be that big, you need to uninstall and install again. Primarily it stores file tracking information, and over time if you don’t purge the file list it will grow in size.
I don’t think it is necessary to uninstall. I believe the file can simply be deleted and Comodo will create an empty one. May need to do the delete in safe mode.
What CIS settings do you lose when deleting this file?
Only the File List?
Deleting will cause unintended side affects so it is safer to re-install. It holds vendor information, root certificates and certificates as part of a digital signature., user accounts and groups, and other tracked data.
I’m really surprised to hear about side effects. I’ve deleted this file more than once without any obvious effects.
W10 Famille - 20H2 - 19042. 1110/ CIS PRO : 12.2.2.7098
Hello,
The size of the cmddata file is 669 440 KB. This seems very important to me.
Thanks for your feedback.
That’s a pretty large file.
Do you know when the cmddata size increases?
For example, when you run a full AV scan or while running another CIS task?
After a full scan the file size does not change.
However, it is likely that the AV will impact the file size.
On my other laptop (FW only) :
W10 Famille - 21H1 - 19043.1110 / CFW : 12.2.2.8012
the file size is 98,604 KB.
I don’t know the function of this file, is it possible to reset/compact it ?
There’s enough information to read about this in this thread.
See futuretech’s posts #85 and #88 for example.
On my laptop with CFW only, last night I wanted to delete the FW logs and in fact it deleted all the logs. It seems that CFW did not like it.
I reinstalled CFW using cicleanuptool and imported the configuration.
The size of cmddata after reinstallation was the same as before uninstallation. The uninstallation had no effect unless 98 MB is a standard size.
It is the standard size after a fresh CIS installation, mine is still at 98MB.
On removing cmddata, futuretech and Citizen K have different opinions.
On the laptop with CAV, I do not know if I venture to delete the file.
For the moment the size is not yet at 1 GB I still have some margin 
Having margin or not, it is unfortunately wasting storage space. . .
I just had a strange experience with CIS, I noticed my 100gb Windows C Drive was nearly full, ran a scan with TreeSize and found the culprit was in Comodo data. I immediately uninstalled CIS and the drive was back to 80% free space. Reinstalling CIS was fine. I am sorry I didn’t identify the problem exactly.
The reason is the increase in the cmddata file along the path C:\ProgramData\Comodo\Cis\lmdb\cmddata, which I once grew to 25 gigabytes.