Hi Ehsan,
The chances of OS file system level corruption is quite high as per the issue description.
I would suggest to engage HPE support team to have a look at the logs before proceeding further with any troubleshooting.
I understand that the unit might be out of warranty. Please try to log a case with chat support team using the below web link to have a look at the MSA log file:
https://pg-receiver-pro.glb.itcs.hpe.com/WclWeb/WclEntry.aspx