Swap usage not available in System monitor

**Cavsfan** · January 11th, 2013

Originally Posted by deadflowr

Your swap UUIDs don't match.
I'd simply edit the fstab file and remove the swap UUID and replace it with the one for sda10.

You guys are good! I also noticed that and fixed it and it mounted.
Thanks!

**Cavsfan** · January 11th, 2013

I hate having to learn the same lesson more than once. But, at least I had fun.

I got rid of my other swap files and trimmed the swap on the primary partition from 4GB to 1GB. I have never seen 2k used on any of my Ubuntus.
I have 4GB of memory and it suspends and wakes just fine.

Then I reboot. Whoops! I'm looking at grub rescue because I had my grub installed on Raring.

I hate when that happens: I forget to install my grub on my main Ubuntu.

Luckily I have been there before and used my Lucid install disk to recover. It worked better than my Quantal disk which kept giving me errors about something missing.

So I gained a little disk space and reduced the number of partitions.

Code:

cavsfan@cavsfan-MS-7529:~$ sudo blkid -c /dev/null -o list
[sudo] password for cavsfan: 
device                 fs_type   label      mount point                UUID
-----------------------------------------------------------------------------------------------------------
/dev/sda1              ntfs      C:         (not mounted)              1CFC7A8DFC7A60C6
/dev/sda2              ext4      Lucid      /media/cavsfan/Lucid       a162dc8a-e4df-4b79-b4c3-524761ff7ae1
/dev/sda3              swap                 <swap>                     2a80f59e-e7c3-418e-aab2-ab5d19255a2f
/dev/sda5              ext4      Precise    (not mounted)              3b8b1954-24e6-4a5e-9074-70a1a94ed4be
/dev/sda6              ext4      Quantal    (not mounted)              b5fc902c-0bf0-45b3-95a1-29f3c46dfe6a
/dev/sda7              ext4      Raring     /                          a6b7ac97-488f-4e87-b6af-247fcbf6df77
cavsfan@cavsfan-MS-7529:~$

Makes me wonder if we even need swap files any more.
Guess I'm cured now. Thanks!

**Cavsfan** · January 11th, 2013

Originally Posted by VinDSL

Working OK here, too...

Maybe the "trick" is to have 1 GiB RAM. LoL!

That must be it! LoL! I see you are using swap and I have never seen any swap used here.

**VinDSL** · January 12th, 2013

Originally Posted by Cavsfan

I see you are using swap and I have never seen any swap used here.

You can always play around with your swappiness settings, so called.

I run the following, at the bottom of my sysctl.conf file (/etc/sysctl.conf)...

Code:

# For Avast!
kernel.shmmax=100000000
#
# Cannot leave things alone
vm.min_free_kbytes = 65536
vm.overcommit_memory = 1
vm.overcommit_ratio = 100
vm.dirty_background_ratio = 5
vm.dirty_ratio = 5
vm.swappiness = 99
#
# Cannot leave these alone either
net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1
#

That should make your swap meter move...

EDIT

Er... I suppose it goes without saying, but...

You'll need to do a restart, after editing this file, in order for the changes to take affect.

**Cavsfan** · January 12th, 2013

Originally Posted by VinDSL

You can always play around with your swappiness settings, so called.

I run the following, at the bottom of my sysctl.conf file (/etc/sysctl.conf)...

Code:

# For Avast!
kernel.shmmax=100000000
#
# Cannot leave things alone
vm.min_free_kbytes = 65536
vm.overcommit_memory = 1
vm.overcommit_ratio = 100
vm.dirty_background_ratio = 5
vm.dirty_ratio = 5
vm.swappiness = 99
#
# Cannot leave these alone either
net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1
#

That should make your swap meter move...

EDIT

Er... I suppose it goes without saying, but...

You'll need to do a restart, after editing this file, in order for the changes to take affect.

I added that to /etc/sysctl.conf, rebooted and still no action in the swappiness.
Surfed a few websites, played a song on Banshee, played a youtube video and still nothing.
Am I finding that swap files may not be necessary if you have like 4GB or more?

You think? Shirley not!

**zika** · January 12th, 2013

I can still clearly remember times when we were complaining about swapping (hence the name of EMACS (Eight Megabytes And Constantly Swapping))... Nowadays complaints are because swap is not (yet) used...

**Cavsfan** · January 12th, 2013

Originally Posted by zika

I can still clearly remember times when we were complaining about swapping (hence the name of EMACS (Eight Megabytes And Constantly Swapping))... Nowadays complaints are because swap is not (yet) used...

That's a good one! LOL!

I wonder if anyone can verify with certainty that a swap file is indeed needed in 2013.

**VinDSL** · January 13th, 2013

Originally Posted by Cavsfan

Am I finding that swap files may not be necessary if you have like 4GB or more?

That's probably the case.

I have a Linux laptop with 4 GiB RAM, and a Linux netbook with 2 GiB RAM, and I've never seen the swap meter move, regardless of what I'm doing.

This 1 GiB desktop machine is constantly swapping.

I occasionally max it out. It doesn't crash, per se, but gets horribly slow and unresponsive, until I start closing programs down.

So, yes, for some of us, swap is paramount. For others, it's left as an exercise in the second-order coefficient. LoL!

**zika** · January 13th, 2013

Originally Posted by Cavsfan

That's a good one! LOL!

I wonder if anyone can verify with certainty that a swap file is indeed needed in 2013.

I have 4GB... Occasionally I can see swap usage. Since I'm most of the time in awesome, fvwm, spetrwm, I do not use so much memory... But when I fire up GS, Unity or such, I'm able to provoke that... I also have vm.swappiness=0 most of the time, so...
Also, there is no proper hibernate without proper swap...

**Cavsfan** · January 13th, 2013

Originally Posted by VinDSL

That's probably the case.

So, yes, for some of us, swap is paramount. For others, it's left as an exercise in the second-order coefficient. LoL!

I'd have to agree!

So, I'll leave all my 'Buntus using the same 1GB as swap just because...

Originally Posted by zika

I have 4GB... Occasionally I can see swap usage. Since I'm most of the time in awesome, fvwm, spetrwm, I do not use so much memory... But when I fire up GS, Unity or such, I'm able to provoke that... I also have vm.swappiness=0 most of the time, so...
Also, there is no proper hibernate without proper swap...

I have no problem "suspending" the PC but, I never cared about using the hibernate option.
Suspend is exactly like "sleep" in Windows 7 and that is what I want, although Ubuntu (all versions) go to sleep in less than 10 seconds while windows takes 2-3 times that amount of time.
Windows has what is very similar to a swap file called a pagefile.
If you let the PC control how much it needs it can become gargantous but, I found I can get by with giving it 300MB and it goes to sleep just fine.

BTW, while I was resizing and moving partitions with Gparted the other day it was almost as slow as windows defragmenting, which is slooooooooooow!
Glad Ubuntu doesn't need to be defragmented.

Oh, if you have a windows OS and have to defragment, that User Journal file ($UsnJrnl$) will get very huge and fragmented and will not defragment at all.
This will greatly speed that process up if you do this before hand.
To open a terminal window, press the "Windows key" and the letter “R”.
You will see the "Run Dialog Box". Type "cmd", and press "OK".
Delete the $UsnJrnl$ by entering fsutil usn deletejournal /n C: and wait until the prompt comes back.
Then defragment (hopefully using Defraggler instead of what comes with windows).
Instead of taking 2 days and not really finishing defragmenting the whole drive, it will complete pretty fast in comparison and do it well.
The user journal file will just rebuild itself after a reboot.

I know a tab more about windows than I do about Linux/Ubuntu but, learning is fun.