PAE vs Default?....

What is the advantage of using the PAE configuration than the default and How can I change or edit the boot menu that gives me the options?

Physical Address Extension - Wikipedia, the free encyclopedia

you can install it in parallel to default and it should add an entry automatically to your boot menu

It is not the configuation that changes but the kernel. The PAE allows to have more than 4GB of memory and additionally activates the NX (No Execute bit) in CPUs that support this, otherwise there is no difference. So it is a bit better to have the PAE kernel for just this NX bit because if you have more than 4 GB of memory then i recommend using 64 bit system (anyway i recommend it always even if you don’t have that much memory as most of the CPU’s support it and are more efficient thanks to additional registers used).

Thanks for the replies and clearing that up for me!

I have it installed now and I would like to change the boot menu to look a bit nicer. Either where is the config file or is there a module I can use?

You can do it in YaST somewhere or other.

My personal preference is to directly edit (as root) /boot/grub/menu.lst, and you should back it up first.

There are blocks of information relating to each menu choice - each will begin ‘title’. They appear in the order they are in the file. Notice the ‘default’ setting near the top, which you may wish to adjust, counts from 0.

I also prefer to manually edit menu.lst. DO keep a separate copy after editing of menu.lst, somewhere safe. When kernel updates are applied, menu.lst is automatically updated to reflect that, and sometimes mistakes occur or boot parameters get dropped.

Ok thanks! I appreciate your help!

Could you go in to a bit more detail please. My system grub menu defaults to PAE,but I have only 2Gb memory. Is there any advantage to making the plain vanilla kernel the default, or should I just leave alone?

Confuseling wrote:

>
> You can do it in YaST somewhere or other.
>

If you would like to do it with yast it’s in Yast–>System–>Boot Loader


kev.

That is fine,leave it as it is, changing to default won’t bring you any differences, additionally with the PAE kernel you are safer (NoExecute bit).

microchip8 wrote:

>
> ‘Physical Address Extension - Wikipedia, the free encyclopedia’
> (http://en.wikipedia.org/wiki/Physical_Address_Extension)
>
> you can install it in parallel to default and it should add an entry
> automatically to your boot menu
>
>
I want to increase my memory to 6GB from 3GB and tried to install the pae
kernel in addition to the regular kernel as you suggested. I get an error
message about rpm64 needing a libc.so.6 which cannot be installed (although
it seems to be). If I tell zypper to ignore some rpm dependencies it comes
back with a long list of things to be changed deleted or added. The list
seems so long that almost everything in my system seems to be affected.
Needless to say, I didn’t proceed.

Allan

Yes BBR that’s what I did, in similar situation to @wakou. I haven’t noticed any difference, but going with PAE seems to be the best advice given by the distro’s installer. :slight_smile:

@aemau

You must have borked something as it works jsut fine and shouldn’t make any problems. Could you post output of

uname -a ??

Doesn’t the default 64bit kernel already support PAE, so why would you need another?

I suspected him to have a 64 bit system hmmm

The PAE kernel is ONLY 32 bit so if you try to install it you will basically change your system to a 32 bit system and from what i’ve heard there is some performance penalty involved when using the PAE kernel and having more than 4 GB of memory. But since the 64 bit kernel is ALREADY supporting such maximum amount of ram you couldn’t ever afford then you are fine :slight_smile:

Exactly so, BBR. My question assumed that he has a 64bit system, from reading his last post. He made the best decision about the looming dependency hell. :slight_smile:

microchip8 wrote:

>
> ‘Physical Address Extension - Wikipedia, the free encyclopedia’
> (http://en.wikipedia.org/wiki/Physical_Address_Extension)
>
> you can install it in parallel to default and it should add an entry
> automatically to your boot menu
>
>
I want to upgrade my system memory from 3GB to 6GB and tried to install
kernel-pae. I receive an error message that the latest version of rpm
needs libc.so.6 which cannot be installed. But it is at least as a
symbolic link. Zypper gives me the option of ignoring this missing
dependency but when I select the option, zypper seems to want to change
just about everything installed on my system. Needless to say, I didn’t
install it. Yast won’t even give me an option.

Allan

consused wrote:

>
> Exactly so, BBR. My question assumed that he has a 64bit system, from
> reading his last post. He made the best decision about the looming
> dependency hell. :slight_smile:
>
>
I guess I misread an earlier posting in this thread which seemed to imply
that the pae kernel was needed both for 32 and 64 bit systems. Glad to
hear I can just increase my memory. Thanks.

Allan

You are welcome. The additional clarification will assist others. It’s easy to miss details, but best to declare 64 or 32bit and any other info, e.g. system software releases, in first posts requesting help. More important is that your own good judgement avoided disaster. :wink:

Thanks for showing me how to change my boot menu! And, I’m happy this thread is helping others too! :slight_smile: