Increase swap size via file

If you find you need to increase the swapsize on linux, simply run the below.

Create a swap file – example below creates 2GB file (1024 x 2072 = 2097152 blocksize) to change the size simply times the swap you need by 1024 and append the number to the count option.

dd if=/dev/zero of=/swapfile1 bs=1024 count=2097152
mkswap /swapfile1 ; chmod 600 /swapfile1

Then enable the swap by running the below

swapon /swapfile1

To confirm the swap has been added use free -m to check.

total used free shared buffers cached
Mem: 5963 4371 1592 0 23 2140
-/+ buffers/cache: 2207 3755
Swap: 3071 0 3071

Mongod max processes

If you encounter a problem with MongoDB with the below error. Its worth checking that your Linux OS does not have an override for your sysctl.conf settings called etc/security/limits.d/90-nproc.conf


[initandlisten] pthread_create failed: errno:11 Resource temporarily unavailable
[initandlisten] can’t create new thread, closing connection


Add a new conf file after with the updated details in the /etc/security/limits.d/ folder entitled 91.mongod.conf. Ensure that the number is after the previous conf file to ensure it gets loaded last.

Example contents

root - nofile 21000
mongod - nofile 21000
mongod soft nproc 62848
mongod hard nproc 62848

Esxi – Add SNMP

To add SNMP to free esxi 5.0 do the below.

Log onto esxi CLI

vi /etc/vmware/snmp.xml

Make the following amendments detailed below

<targets>YOURSERVERIPHERE@161 public</targets>
</snmpSettings> restart

The server should now be available to be polled via snmp.