Originally Posted by justacoupleofquestions
trying to understand primary, logical and extended partitions and how to use them when installing arch linux
Linux doesn't care whether its partitions are primary or logical.
A disk can have up to four primary partitions or up to three primary partitions plus one extended partition.
An extended partition is a container that can hold several logical partitions.
in dual boot with win7.
Laptop. 1 disc. 2 partitions. C: for win7 and Q: for recovery.
These has to be intact when installing Arch Linux.
You need some unpartitioned space to install Linux. So if your win7 partition and recovery partition fill the drive, you will need to first shrink the C: partition before installing Linux.
Shrinking the C: partition is best done within Windows 7. But do not create partitions for Linux within Windows. Instead leave the space unpartitioned.
I'm not sure about arch Linux: Most Linux installers are designed with an obvious choice to use the unpartitioned space on a drive and the installer will partition that space for you as appropriate for that install.
In other cases, it may be easier to boot a Linux liveCD and use the GUI partitioning tool to create the desired Linux partitions before running the installer.
You probably want just a / partition and a swap partition. With just two Windows partitions plus just two Linux partitions, it would be possible to have all four primary. But I suggest making one extended partition from all the space freed by shrinking C: (and/or space that was already unpartitioned before shrinking C:) then make both (all) Linux partitions logical. If you need to use a liveCD to move and shrink partitions later to add more partitions, having logical partitions for Linux gives you more flexibility. Having four primary partitions gives you zero flexibility.