One way replication of mysql database:

                             Mysql replication help us in keeping the data replicated to one or more sites reliably with binary logs. Apart from good amount of advantages Mysql replication doesnt help with data corruption, since the corrupted data is replicated in all slaves. It is good to have periodic backup of database apart from replication.

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What is an SPF record, and what is it used for?

Sender Policy Framework (SPF) is actually an e-mail validation system designed to prevent e-mail spam by addressing a common susceptibility to get attacked.

The main design intent of the SPF record is to allow a receiving MTA (Message Transfer Agent) to ask the nameserver of the domain which appears in the email (sender) and check if the originating IP of the mail (source) is authorized to send mail for the sender’s domain. The mail sender is required to publish an SPF but the sending MTA is unchanged.

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Partition creation

1. format the present disk
#fdisk -l
represent all the present HD and the mount partitions on each.
Here you can now check the HD you want to have the partition and then

2. create partition
#fdisk /dev/sd<a,b,c>
select the HD that you want to create the partition and then create the partition you want or delete the unwanted ones by following the options listed there. You can create new ones with desired size too and write and quit.

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How to stop core file generation

                        A core file records memmory image of running process.when a php process is killed, apache creates core files under your account.These core files takes too much of space on server.There is no harm on deleting these files.You cabn get rid off these core files by modifiying the httpd start up file.

Vi /etc/init.d/httpd

Search for ulimit lines ex:

ulimit -n 1024

ulimit -n 4096

ulimit -n 8192

ulimit -n 16384

Please add ulimit -c 0 to the end.So its looks like

ulimit -n 16384

ulimit -c 0

Save the changes and restart apache service.