Linux AS 3 swap question!!

[Rick Stevens]

On Sat, 2006-02-25 at 23:09 +0530, mac wrote:
> Hi,
> We have a Linux EL AS 3 running on a poweredge server with 8 GB
> ram ...we would like to know how to change the swap space on a linux
> AS 3 system dynamically
> 
>  and would AS3 support a swap size of 16 GB
> 
> any pointers appreciated

You can have up to 16 swap sections but each is limited to 2GB each,
giving a total of 32GB of swap.  You can't change the swap size
dynamically, since the swap is on a fixed-size partition or file.  You
can enable and disable various swap files or partitions using the
swapon(8) or swapoff(8) commands.

Swap has to be either a separate partition OR a zero-filled file.  You
probably know how to make a swap partition.  To create a swap _file_:

1. Find a partition that has enough free space for the swap you want.

2. As root, do:

	# dd if=/dev/zero of=/path/to/swap/file count=size

For example, to create a 2GB swap file called "/var/swapfile":

	# dd if=/dev/zero of=/var/swapfile count=2G

3. Convert the file to a swap file:

	# mkswap /var/swapfile

3. Activate via:

	# swapon /var/swapfile

4. Edit your /etc/fstab file and add a line for this swap file so it'll
activate on the next boot:

	/var/swapfile   swap          swap    defaults        0 0

Voila!

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- Rick Stevens, Senior Systems Engineer     rstevens at vitalstream.com -
- VitalStream, Inc.                       http://www.vitalstream.com -
-                                                                    -
-        God is real...........unless declared integer or long       -
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