swap space increase

[james gould]

Have 8gb total memory installed on rp4440 server. Want to increase swap space to double
to 16gb. Here is the output from swapinfo -tam

Mb Mb Mb PCT START/ Mb
TYPE AVAIL USED FREE USED LIMIT RESERVE PRI NAME
dev 4096 0 4096 0% 0 - 1 /dev/vg00/lvol2
dev 4000 252 3748 6% 0 - 0 /dev/vg00/lvol9
reserve - 7844 -7844
memory 6305 4757 1548 75%
total 14401 12853 1548 89% - 0 -


Not sure best way to increase the swap on the root volume disk.

[James R. Ferguson]

Hi James:

First, secondary swap doesn't have to be on vg00.

That said, do something like:

# lvcreate -C y -r n -L 8092 -n lvolX /dev/vgNN

# swapon -p 0 /dev/vgNN/lvolX

# echo "/dev/vgNN/lvolX ... swap pri=0 0 0" >> /etc/fstab

Regards!

...JRF...

[Steven E. Protter]

Shalom,

You don't want to increase swap to 16 GB.

8 GB is more than enough.

Check vmstat.

If you are really paging, you don't need more swap, you need more ram.

Large memory systems need not have twice ram as swap. 8-12 gb is sufficient.

If you still want to do it, the best way to go is device swap.

SEP

[Sharma Sanjeev]

Hi James

You can use below steps to create additional Swap

Use the following procedure to add filesystem as a secondary swap

1. create a separate vg for it. After that you can do this to create your addl swap.

2. # lvcreate -L 4000 -n swap2 -C y -r n /dev/vg01
==> create 4000MB contigous lv called swap in vg01 with bad block reallocation turned off

3.# swapon -p 1 /dev/vg01/swap2
==> enable swap with priority 1.

4.# swapinfo -ta
==> check to see if added swap is enabled.

5. # vi /etc/fstab
....
/dev/vg01/swap2 ... swap pri=1 0 1

Regards
Sanjeev