Cloning an entire drive
You’ll need two hard drives the same size, or a destination drive larger than the source drive.
Make sure no partitions are mounted on either drive. In this example /dev/hda is the source drive, /dev/hdb is the destination drive. The dd command makes an exact, byte-for-byte copy, including the MBR (master boot record):
# dd if=/dev/hda of=/dev/hdb
Apache Graceful Restart Process
Signal: USR1
The USR1 or graceful signal causes the parent process to advise the children to exit after their current request (or to exit immediately if they’re not serving anything). The parent re-reads its configuration files and re-opens its log files. As each child dies off the parent replaces it with a child from the new generation of the configuration, which begins serving new requests immediately.
This code is designed to always respect the process control directive of the MPMs, so the number of processes and threads available to serve clients will be maintained at the appropriate values throughout the restart process.
Apache Security Tips - Permissions on ServerRoot Directories
In typical operation, Apache is started by the root user, and it switches to the user defined by the User directive to serve hits. As is the case with any command that root executes, you must take care that it is protected from modification by non-root users. Not only must the files themselves be writeable only by root, but so must the directories, and parents of all directories. For example, if you choose to place ServerRoot in /usr/local/apache then it is suggested that you create that directory as root, with commands like these:
mkdir /usr/local/apache
cd /usr/local/apache
mkdir bin conf logs
chown 0 . bin conf logs
chgrp 0 . bin conf logs
chmod 755 . bin conf logs
It is assumed that /, /usr, and /usr/local are only modifiable by root. When you install the httpd executable, you should ensure that it is similarly protected:
cp httpd /usr/local/apache/bin
chown 0 /usr/local/apache/bin/httpd
chgrp 0 /usr/local/apache/bin/httpd
chmod 511 /usr/local/apache/bin/httpd
You can create an htdocs subdirectory which is modifiable by other users — since root never executes any files out of there, and shouldn’t be creating files in there.