Azure Linux VM's OmsAgent eating up local disk space

Question

Hello,

I have enabled diagnostic setting for my Linux VM to send log data to storage account

The extension also got added as expected.

Now the problem is that the omsagent has started generating lot of local files in the VM disk which eventually eating up the disk space as follows

total 1.3G
-rwxr-xr-x. 1 omsagent omiusers 1.3G Oct 18 09:16 omsconfigdetailed.log
-rwxr-xr-x. 1 omsagent omiusers 42M Oct 18 09:16 omsconfig.log

Now is there any way to stop this local file generation? Please advise

Answer 1

Hello, @Atanu Gupta !

How do I prevent the OmsAgent logs from taking up local disk space on my VM?
You may notice that omsconfigdetailed.log and omsconfig.log are taking up space on your VM. While there is currently no way to disable these logs, you are able to change the size of the logs using the logratate settings.

Additionally, you can consider using the new Azure Monitor Agent (AMA), which doesn't run into this issue. The legacy Log Analytics agent (OMS) will be deprecated by August 2024.

This GitHub issue goes into more detail on logratate:
https://github.com/microsoft/omi/issues/531#issuecomment-398624551

omsconfig's logrotate setting like below:
https://github.com/Microsoft/PowerShell-DSC-for-Linux/blob/master/Providers/Extras/Scripts/omsconfig_logrotate.conf

jumping@jumping-ub14:/root$ cat /etc/logrotate.d/omsconfig
/var/opt/microsoft/omsconfig/omsconfig.log {
rotate 5
sharedscripts
weekly
size 50M
compress
}

/var/opt/microsoft/omsconfig/omsconfigdetailed.log {
rotate 5
sharedscripts
size 50M
compress
}
jumping@jumping-ub14:/root$

Additional reference:

• Linux VM OmsAgent logs

Answer 2

The reason behind this is the extensive amount of logs that OMS agent generates. While it is not possible to disbale those oms logs files but you can limit the log file size using the logrorate(/etc/logrotate.d).
The below is the logrorate settings I use to control the file size:

cat /etc/logrotate.d/omsconfig
/var/opt/microsoft/omsconfig/omsconfig.log {
rotate 7
sharedscripts
weekly
size 100M
compress
}
/var/opt/microsoft/omsconfig/omsconfigdetailed.log {
rotate 7
sharedscripts
size 100M
compress
}