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Old 02-14-2013, 04:46 AM   #1
yashfire007
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How to extend SWAP memory


Dear all,

I am having 4Gb of RAM in my machine , but i have assigned only 6GB for SWAP.
Now i need to extend it to 8GB, please suggest.

Thanks in advance..



Best regards,
Mohammed yasin...
 
Old 02-14-2013, 04:54 AM   #2
RaviTezu
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1.You need a partition to expand the swap.(you can use fdisk command )
2.Let's take /dev/sda6 as example.
3.Run sudo mkswap /dev/sda6
4.Technically speaking, you’re not formatting the partition; rather,you’re writing a small amount of information to indicate to the kernel that it can be used as swap space.
You can immediately activate the new swap partition via the swapon command. This command tells the kernel it can use the specified partition as swap space.
5.Run sudo swapon /dev/sdb6
This command will complete without printing anything, but you can check dmesg for
information on what happened.
 
Old 02-14-2013, 04:55 AM   #3
RaviTezu
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just FYI: You can use "free -m" command to check the swap memory.
 
Old 02-14-2013, 05:03 AM   #4
syg00
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Quote:
Originally Posted by yashfire007 View Post
Now i need to extend it to 8GB
How did you reach that conclusion ?.
Do you have a swapping issue, or are you merely following an old (probably wrong in your case) "rule-of-thumb" ?.
 
Old 02-14-2013, 05:22 AM   #5
RaviTezu
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Quote:
Originally Posted by syg00 View Post
How did you reach that conclusion ?.
Do you have a swapping issue, or are you merely following an old (probably wrong in your case) "rule-of-thumb" ?.
You should have a 2GB(atleast) partition as you require.

As you have 6GB+(New partition)=8GB of swap memory
 
Old 02-14-2013, 05:44 AM   #6
yashfire007
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Quote:
Originally Posted by RaviTezu View Post
1.You need a partition to expand the swap.(you can use fdisk command )
2.Let's take /dev/sda6 as example.
3.Run sudo mkswap /dev/sda6
4.Technically speaking, you’re not formatting the partition; rather,you’re writing a small amount of information to indicate to the kernel that it can be used as swap space.
You can immediately activate the new swap partition via the swapon command. This command tells the kernel it can use the specified partition as swap space.
5.Run sudo swapon /dev/sdb6
This command will complete without printing anything, but you can check dmesg for
information on what happened.
If have created a new partition for SWAP , Is there will be two SWAP partitions in my system..
 
Old 02-14-2013, 05:56 AM   #7
RaviTezu
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Quote:
Originally Posted by yashfire007 View Post
If have created a new partition for SWAP , Is there will be two SWAP partitions in my system..
Yes. You'll have 2 swap partitions.
 
Old 02-14-2013, 07:26 AM   #8
goumba
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You can also create a swap file. From what I have read there is no performance difference between using a swap file and partition. So if you don't have the ability to add/resize a swap partition, but create a swap file and add that to fstab and the two should work in tandem (such has been the case for me). See https://wiki.archlinux.org/index.php/Swap
 
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Old 02-14-2013, 07:29 AM   #9
Pastychomper
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I'd vote for a swap file too.

Traditionally, swapfiles have disadvantages when compared to dedicated partitions, but the big one - that the kernel has to go through an extra layer to access a file, which used to reduce performance - has been overcome in modern kernels.

You still have the potential problems of file fragmentation and not being able to choose where the file physically sits on the hard disc, though. (I'm assuming you have a traditional hard disc - SSDs are a different kettle of fish.) It's possible to place a swap partition on the outer edge of the disc, which reduces read/write times, but a file doesn't give you that luxury. On the other hand, a lot of people don't bother anyway, and as you are already using the system, the best parts of the disc might already be taken.

If you happen to have two hard discs, it's often worth having a swap partition/file on each with equal priority. The kernel alternates the swapping reads (or writes) between them, giving a significant performance boost. If your two swaps are both on the same device, then giving one of them a lower priority avoids the risk of making the disc heads 'dance' between two parts of the disc every time you swap.

Last edited by Pastychomper; 02-14-2013 at 07:36 AM. Reason: Jinxed :)
 
Old 02-14-2013, 07:42 AM   #10
goumba
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Quote:
Originally Posted by Pastychomper View Post
Last edited by Pastychomper; Today at 07:36 AM. Reason: Jinxed
I didn't say your name : punch:
 
  


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