Hi, Alex, as per your previous suggestion, we did all the "troubleshooting" steps in the link for SmpScale. Working on them removed the errors in our 1st Squid installation (original email). Now, we are facing problem on another machine. We did all those steps mentioned in SmpScale, yet this machine is giving the same problems. SHM is already installed. Amos, as for file permission, the following all have permission as "squid.squid": /var/run/squid /var/log/squid ls on /dev/shm shows: [root@proxy04 ~]# ll /dev/shm total 124912 -rw------- 1 squid squid 7340144 Jul 12 06:57 squid-cache_mem.shm -rw------- 1 squid squid 68159528 Jul 12 06:57 squid-cachestore.cache1.rock.shm -rw------- 1 squid squid 68159528 Jul 12 06:57 squid-cachestore.cache4.rock.shm -rw------- 1 squid squid 16 Jul 12 06:57 squid-io_file__metadata.shm -rw------- 1 squid squid 262228 Jul 12 06:57 squid-io_file__queues.shm -rw------- 1 squid squid 84 Jul 12 06:57 squid-io_file__readers.shm -rw------- 1 squid squid 2295383692 Jul 12 06:57 squid-squid-page-pool.shm So, Squid process does seem to be able to read / write to SHM. This is the output of "df": [root@proxy04 ~]# df -H Filesystem Size Used Avail Use% Mounted on /dev/sda3 63G 9.2G 50G 16% / tmpfs 4.1G 128M 4.0G 4% /dev/shm /dev/sda1 204M 114M 80M 59% /boot /dev/sdb 316G 235M 299G 1% /cachestore/cache1 /dev/sdc 316G 251M 299G 1% /cachestore/cache4 shm 4.1G 128M 4.0G 4% /dev/shm SELINUX is disabled. [root@proxy04 ~]# sestatus SELinux status: disabled What else could be interfering with the SHM? Regards HASSAN On Sat, Jul 12, 2014 at 9:46 AM, Alex Rousskov <rousskov@xxxxxxxxxxxxxxxxxxxxxxx> wrote: > On 07/11/2014 07:23 PM, Nyamul Hassan wrote: >> However, whenever we start without the "-N", we get the same error: >> FATAL: Rock cache_dir at /cachestore/cache1/rock/rock failed to open >> db file: (11) Resource temporarily unavailable > > Most likely, this is a side effect, not the cause. Ignore until all > other errors are gone. > > >> We are also seeing these lines: >> commBind: Cannot bind socket FD 17 to [::]: (13) Permission denied > > This is a real problem. A solution may be found in the Troubleshooting > section of http://wiki.squid-cache.org/Features/SmpScale > > > HTH, > > Alex. >