Increase Swap

[Harstad]

Hi

How can I increase Swap area in a Linux?

I don´t know the commands to do it and the steps.

free -k
total used free
Swap: 4194192 317388 3876804


sfdisk -s
total: 35561280 blocks

[Huc_1]

do a
#fdisk -l
this will show you your partition on of the is a swap parttion.
If you want to increase this it means re partioning your disk ... that is if there is some space left to partition/use.

If you need more swap for some reason you can always use swap to a file read man swapon

swapon -s

will tell you what swap you are using

J-P

[Mark Grant · Accepted solution]

You can do either file or device swap. Device swap is the easiest but you need a free partition to do it.


DEVICE SWAP

using fdisk, make a partition and give it an id of Linux Swap (82).

run mkswap /dev/hdaX where X is your partition number

run "swapon -p X" where X is a priority between 0 and 32767 (low number are higher priorirty) though you can leave this step off if you want it to have the same priority as your existing swap

run "swapon -a"

edit /etc/fstab and pretty much copy the exisiting entry for swap but changing the device.

FILE SWAP

Choose a place to put your file swap

run "dd if=/dev/zero of=/swapfile bs=1024 count=XXXX" where XXXX is the size of the swapfil in Kilobytes

"mkswap /swapfile"

"swapon -p X" if you want ot set priority X

Edit /etc/fstab as above.

I think that's everything.

[Harstad]

Hi All

Thanks for your help.

Ok,,the swap space has been increased, but doing a:

fdisk -l /dev/cciss/c0d0

I can´t see the new swap partition.

Thanks

Harstad

[Huc_1]

swapon -s
should show that

J-P

[Harstad]

Hi

It´s Ok,,

swapon -s
Filename Type Size Used Priority
/dev/cciss/c0d0p7 partition 2097096 0 -1
/dev/cciss/c0d0p10 partition 2097096 0 -2
/dev/cciss/c0d0p11 partition 2097136 0 -3

but executing:

#fdisk -l /dev/cciss/c0d0

/dev/cciss/c0d0p11 550 1320 3145664 83 Linux

is strange..

Thank

[Huc_1]

Yes that is strange !

I dont know the why ??

what does the sfdisk -l see
there should be an entry for swap file in there
or else something is wrong !

what does the command fdisk -l /dev/cciss not /dev/cciss/c0d0p11 show ?

Sorry I do not have cciss devices so can not check myself

J-P ( 0 points for this answer pls, more questions then answers really)

[Mark Grant]

You need to change the partition type from 83 to 82. Run fdisk, type "t", select partition and put in "82"

[Harstad]

Hi Huc

Answering your questions:

fdisk -l /dev/cciss not /dev/cciss/c0d0p11

Disk /dev/cciss/c0d0p11: 255 heads, 32 sectors, 770 cylinders
Units = cylinders of 8160 * 512 bytes

Disk /dev/cciss/c0d0p11 doesn't contain a valid partition table

sfdisk -l

nting from 0

Device Boot Start End #cyls #blocks Id System
/dev/cciss/c0d0p1 * 9 33 25 102000 83 Linux
/dev/cciss/c0d0p2 34 162 129 526320 83 Linux
/dev/cciss/c0d0p3 0+ 8 9- 36704 12 Compaq diagnostics
/dev/cciss/c0d0p4 163 8715 8553 34896240 5 Extended
/dev/cciss/c0d0p5 163+ 291 129- 526304 83 Linux
/dev/cciss/c0d0p6 292+ 548 257- 1048544 83 Linux
/dev/cciss/c0d0p7 1320+ 1833 514- 2097104 82 Linux swap
/dev/cciss/c0d0p8 1834+ 2347 514- 2097104 83 Linux
/dev/cciss/c0d0p9 2348+ 2861 514- 2097104 83 Linux
/dev/cciss/c0d0p10 2862+ 3375 514- 2097104 82 Linux swap
/dev/cciss/c0d0p11 549+ 1319 771- 3145664 83 Linux
/dev/cciss/c0d0p12 3376+ 8715 5340- 21787184 83 Linux
# ^H
ksh:: not found
# fdisk -l /dev/cciss not /dev/cciss/c0d0p11

Disk /dev/cciss/c0d0p11: 255 heads, 32 sectors, 770 cylinders
Units = cylinders of 8160 * 512 bytes

Thanks

[Huc_1]

dev/cciss/c0d0p11 should be of type 82 that is linux swap not 83 Linux

for ex: your patition 07 is a valid swap partition

dev/cciss/c0d0p7 1320+ 1833 514- 2097104 82 Linux swap

If c0d0p11 is the "new" swap partition you wanted to use and is not used/mounted on your file system as a linux valid mount point then
do

#swapoff dev/cciss/c0d0p11

After that follow Mark Grant advised and change file type using fdisk t option on partition, when this is written to disk do as you did previously so to use it.

Then check agains fdisk -l

Keep us informed of progress.

J-P

[Harstad]

Hi Huc

I will keep you informed.

Thanks for your hekp.