Here's my filesystem: Filesystem 1K-blocks Used Available Use% Mounted on /dev/mapper/system-root 92755960 7827884 80193308 9% / devtmpfs 8177376 60 8177316 1% /dev tmpfs 8190700 5840 8184860 1% /dev/shm tmpfs 8190700 17812 8172888 1% /run tmpfs 8190700 0 8190700 0% /sys/fs/cgroup /dev/sda1 387456 189953 172979 53% /boot /dev/mapper/system-ssd 103589120 13909464 84394588 15% /ssd /dev/mapper/system-var 41153856 964864 38075456 3% /var tmpfs 8190700 17812 8172888 1% /var/run tmpfs 8190700 17812 8172888 1% /var/lock And permissions: # ls -al /dev/shm total 5840 drwxrwxrwt 2 root root 140 May 22 17:26 . drwxr-xr-x 19 root root 4080 May 22 17:15 .. -rwx------ 1 root root 67108904 May 22 16:45 pulse-shm-1091930706 -rwx------ 1 root root 67108904 May 22 16:45 pulse-shm-2870669293 -rwx------ 1 root root 67108904 May 22 16:45 pulse-shm-4040921779 -rw------- 1 squid squid 7864392 May 22 17:29 squid-cache_mem.shm -rw------- 1 squid squid 0 May 22 17:29 squid-squid-page-pool.shm Notice that there are already squid files in the directory... so permissions should be good. Maybe the size is the problem? Best regards, The Geek Guy Lawrence Pingree http://www.lawrencepingree.com/resume/ Author of "The Manager's Guide to Becoming Great" http://www.Management-Book.com -----Original Message----- From: fernando@xxxxxxxxxxxxx [mailto:fernando@xxxxxxxxxxxxx] Sent: Thursday, May 22, 2014 8:48 AM To: squid-users@xxxxxxxxxxxxxxx Subject: RE: configuring Eliezer RPMs for CentOS 6 for SMP Hi Lawrence, > Here's the error I am getting and my squid.conf > > FATAL: Ipc::Mem::Segment::create failed to > ftruncate(/squid-squid-page-pool.shm): (22) Invalid argument If squid can't create the shm file, you should check your OS configuration. It's not squid fault, the server Os has to be configured to provide enough shared memory to squid. Most of the time, it's enough to mount tmpfs mounted as /dev/shm, but I'm not familiar with SuSE installation defaults. > cache_dir aufs /ssd/squid/cache0 45000 64 1024 > cache_dir aufs /ssd/squid/cache1 45000 64 1024 This won't work in smp mode. Each worker needs a dedicated cache_dir, except for rock store. But your squid never reached that point. The way you did all workers will try to use both cache_dirs. I guess you want one for each worker. So replace those two lines by: cache_dir aufs /ssd/squid/cache${process_number} 45000 64 1024 That way each worker will use only it's own, exclusive, cache dir. > workers 2 Ok, you are trying to use 2 workers. []s, Fernando Lozano