Cisco Cisco Email Security Appliance C160 Mode D'Emploi

To prevent log files on the appliance from becoming too large, AsyncOS performs a “rollover” and 
archives a log file when it reaches a user-specified maximum file size or time interval and creates a new 
file for incoming log data. Based on the retrieval method defined for the log subscription, the older log 
file is stored on the appliance for retrieval or delivered to an external computer. See 

 for more information on how to retrieve log files from the appliance.

When AsyncOS rolls over a log file, it performs the following actions:

Renames the current log file with the timestamp of the rollover and a letter “

” extension signifying 

saved.

Creates a new log file and designates the file as current with the “

” extension.

Transfers the newly saved log file to a remote host (if using the push-based retrieval method).

Transfers any previously unsuccessful log files from the same subscription (if using the push-based 
retrieval method).

Deletes the oldest file in the log subscription if the total number of files to keep on hand has been 
exceeded (if using the poll-based retrieval method).

You define a log subscription’s rollover settings when creating or editing the subscription using the 
System Administration > Log Subscriptions page in the GUI or the 

logconfig

 command in the CLI. The 

two settings available for triggering a log file rollover are:

A maximum file size. 

A time interval.

AsyncOS rolls over log files when they reach a maximum file size to prevent them from using too much 
disk space. When defining a maximum file size for rollovers, use the suffix 

m

 for megabytes and 

k

 for 

kilobytes. For example, enter 

10m

 if you want AsyncOS to roll over the log file when it reaches 10 

megabytes. 

If you want to schedule rollovers to occur on a regular basis, you can select one of the following time 
intervals:

None. AsyncOS only performs a rollover when the log file reaches the maximum file size.

Custom Time Interval. AsyncOS performs a rollover after a specified amount of time has passed 
since the previous rollover. To create a custom time interval for scheduled rollovers, enter the 
number of days, hours, and minutes between rollovers using 

d

, 

h

, and 

m

 as suffixes.

Daily Rollover. AsyncOS performs a rollover every day at a specified time. If you choose a daily 
rollover, enter the time of day you want AsyncOS to perform the rollover using the 24-hour format 
(HH:MM). 

Only the GUI offers the Daily Rollover option. If you want to configure a daily rollover using the 

logconfig

 command in the CLI, choose the Weekly Rollover option and use an asterisk (*) to 

specify that AsyncOS should perform the rollover on every day of the week.