Ротация логов в сквиде
#  TAG: logfile_rotate
#       Specifies the number of logfile rotations to make when you
#       type 'squid -k rotate'.  The default is 10, which will rotate
#       with extensions 0 through 9.  Setting logfile_rotate to 0 will
#       disable the rotation, but the logfiles are still closed and
#       re-opened.  This will enable you to rename the logfiles
#       yourself just before sending the rotate signal.
#      
#       Note, the 'squid -k rotate' command normally sends a USR1
#       signal to the running squid process.  In certain situations
#       (e.g. on Linux with Async I/O), USR1 is used for other
#       purposes, so -k rotate uses another signal.  It is best to get
#       in the habit of using 'squid -k rotate' instead of 'kill -USR1
#       <pid>'.
#      
#Default:
logfile_rotate 10
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If you set logfile_rotate to 0, Squid simply closes and then re-opens the logs. This allows third-party logfile management systems, such as newsyslog, to maintain the log files.
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Кроме того юзается файл  /etc/logrotate.d/squid
Который имхо можно просто удалить.
p.s.
http://www.squid-cache.org/mail-archive/squid-users/200610/0...