=============================================
php stressx.php clear
php stressx.php write sfcache  50000 10000
php stressx.php read sfcache   500000
php stressx.php delete sfcache 500000
=============================================

"delete" may do the job too fast and cache folder may be be empty most of time.
Adjust the usleep(1000*1000); function in "deleteProc"

[SOLVED]--------------
PHP Warning:  filesize(): stat failed for /var/www/phpkobo/my-projects/sfcache/v3/public_html/test/stress-test/cache/main.2d6bf43bad8c1840b0aae96bea18f66c.cache in /var/www/phpkobo/my-projects/sfcache/v3/public_html/sfcache/CLockCrud.class.php on line 56
----------------------