A "Tail" logging terminal session may occasionally hang and cannot be exited
Technical Articles ID:
KB84480
Last Modified: 5/21/2020
Environment
McAfee VirusScan Enterprise for Linux (VSEL) 2.0, 2.0.1, 2.0.2
All supported Linux operating systems
Problem
A terminal session to "Tail" a live log file generated by an application occasionally stops working and cannot be exited using CTRL+C. When this occurs, that particular session can be exited only after you disable the VSEL On-Access Scanner, or stop the nails service (with the command /etc/init.d/nails stop).
Cause
McAfee has determined that the issue is actually in the Fanotify feature of Linux Kernels when multiple threads iterate to the same directory or files. This can result in some threads hanging.
This issue is not directly related to or caused by VSEL. Any future solution must come from the Kernel and development teams for the Linux operating systems involved. If you experience this issue, McAfee recommends that you contact support for the operating system manufacturer.
Until the manufacturers resolve the issue, you can use the following workaround.
Workaround
Use the following commands to run tail or tailf with output buffering disabled:
#unbuffer tail –f /dir/logfile
#unbuffer tailf –n /dir/logfile
Related Information
Related issue caused by the same issue in Fanotify: KB85826 - IBM DB2 backup session halts and hangs at 99% when VirusScan Enterprise for Linux 2.0.x On-Access Scanner is enabled
