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-   -   Memory reported less than installed (Mandrake 10) (http://www.linuxquestions.org/questions/linux-hardware-18/memory-reported-less-than-installed-mandrake-10-a-307127/)

vo24 03-28-2005 04:50 PM

Memory reported less than installed (Mandrake 10)
 
Actual physical RAM present in the machine is 2048MB.
The amount of RAM reported in the Information section of the Configure Your Desktop utility is 882,61MB.

Freshly installed Mandrake 10 (2.6.3-7mdksmp). The box is HP xw8000 workstation (reported to be certified by Mandrake).

Any ideas to correct this unfortunate situation are highly appreciated. I am a relative novice to the OS.

mrGenixus 03-28-2005 04:54 PM

where is this value reported?

Is this consistent?

Does this cause any problems?

How much RAM does 'top' report?

vo24 03-28-2005 05:26 PM

-where is this value reported?
In Configure your desktop utility (Star menu > System > Configuration > Configure your desktop). It has "Information" section with nice colored graphical memory consumption charts. It reports "Total physical memory = 882,61MB".

-Is this consistent?
It is, if you mean from boot to boot. In the two places where there are reports on the RAM size the figures are consistent too (albeit slightly different).

-Does this cause any problems?
Not. However, losing more than half of hard-earned RAM is not the way it should be, is it?

-How much RAM does 'top' report?
There's another place that reports RAM: Mandrakelinux Control Center (Star menu > System > Configuration > Configure your computer). In Boot Loader section, it has an option/text field "Specify precise RAM size if needed". "Found 896MB" it says here. Specifying the correct, real amount of physical RAM installed does NOT change the amount of RAM reported.

mrGenixus 03-28-2005 06:11 PM

but how much ram does 'top' report?

how about 'cat /proc/meminfo'

Also, if there isn't any problems, then quit whining and realize that if you're not experienceing problems, you've just got too much RAM

vo24 03-28-2005 06:23 PM

Both top and cat report 903792k of total memory. The installed amount, as I noted above, is 2048MB.

There's no such thing as too much memory IMHO. Also, it clearly is a misconfiguration somewhere in the OS. An unhealthy sign from any point of view. There must be a solution.

mrGenixus 03-28-2005 06:41 PM

Is your BIOS detecting the RAM?, check dmesg to make sure the kernel is compiled to use that much memory, or that it's being detected.

vo24 03-28-2005 07:06 PM

The BIOS and WinXP (it's a dual-boot machine) report the correct amount.

I've parsed dmesg output for any indications that kernel isn't compiled to use 2 GB of RAM (or any other amount) or in fact anything regarding RAM specifically. I may have missed such indications if they are indirect: I'm not yet an expert. In all other respects, dmesg outputs rather faithfully on all other pieces of hardware that I have.

Do you know of any surefire way to remedy the situation? I mean like downloading the latest kernel, re-compiling it with any parameters pertaining to the specific machine. I've never done this before, but I don't think it's beyond human powers anyway, and I'll be sure to google for HOWTOs.

Anyway, do you have any specific advice on the kernel recompilation procedures? Do you think the recompilation has a high probability of correcting the issue?

mrGenixus 03-28-2005 07:28 PM

My advice regaring kernel recompile is this: don't let it psych you out. It's somewhat easier on non-prepackaged distros like MDK / FC / RH.

Find the Howto, if you can, make sure it's a mandrake howto, and you should be fine.

jiml8 03-28-2005 08:18 PM

You are using the wrong kernel. You need to use a kernel that is compiled to use up to 4 Gigs. One is provided with Mandrake.

Why are you using the SMP kernel? You didn't specify your HW configuration; is this a multi-processor box? if not you don't need the SMP kernel.

You need this one, which should be on your distro:

kernel2.6.3-7mdk-i686-up-4GB

and in fact you should upgrade that to a later version which you can do using urpmi.

I am using a single processor box myself so I can't say for sure, but I do believe there is an smp kernel provided that handles 4gigs. If there isn't you can compile your own.

vo24 03-28-2005 08:32 PM

Right. About the wrongness of my kernel choice I've just figured out myself. But the wrongness is only about RAM: I seem to need the "up-4GB" kernel.

On the other hand, mine is a good old two-processor box (2xXeon3.06) with 2GB of RAM. This would require an SMP kernel, I thought. What do I do now with the kernel choice?

P.S. I'm doing urpmi --auto-select now.

jiml8 03-28-2005 08:43 PM

mandrake provides this kernel, which is available from an update repository (I am looking at it now at indiana.edu - ftp.uwsg.indiana.edu/linux/mandrake/official/updates/10.0/RPMS)

kernel-p3-smp-64GB-2.6.3-25mdk-1-1mdk.i586.rpm

This should be the one you need.

vo24 03-28-2005 08:55 PM

I thought so too. But is it ok that the name implies Pentium III processor which is not true, strictly speaking, in my case?

Also, I'm now in the process of updating via urpmi. Can I halt this process (to reboot and try another kernel) without having to redownload the updates already downloaded?

J.W. 03-28-2005 09:32 PM

This article does a nice job of explaining how Linux manages memory and I think it would be of interest. If you will recompiling your kernel, then Yes, if you've got a P4 (or whatever) then you can specify the exact CPU architecture during that process as well. Good luck with it -- J.W.

Welcome to LQ!

jiml8 03-28-2005 09:39 PM

Quote:

kernel-p3-smp-64GB-2.6.3.25mdk-1-1mdk.i586.rpm
Memory fails me. Is Xeon older than P3? If so then potentially there would be a problem since the optimization will be for P3.

Really, I can't tell you, but trying won't hurt. If there is a problem booting all you need to do is go into the /boot/ directory and change the symlinks back to the old kernel.

In the alternative, as has been suggested, you can just compile your own kernel. This isn't difficult, and you could set every option that you wanted. You would need to get the complete kernel source, and not the stripped Mandrake version. You would get the source from kernel.org.

vo24 03-28-2005 10:18 PM

I'm now booted with "2.6.3-7mdk-p3-smp-64GB" version. The RAM size is REPORTED CORRECTLY. I've also found a link to an rpm of a newer 2.6.8 series kernel from Mandrake: it has "enterprise" in it's name and is supposedly more of a server-oriented thing. At the same time, there are what can be called "poweruser desktop" variants.

The thing with me is that my workstation is a mixture of hardware found in servers AND desktops: memory, smp, scsi, tape drive and at the same time color calibration device, monitor with large resolution / refresh rate/ color depth (with which there's a problem too now, but that's going to be another thread). I'm doing a good deal of heavy lifting related to publishing; I'm looking at Scribus, LittleCMS, Gimp, GhostScript, etc. and some other apps that could fit in the workflow at some point or maybe even constitute a closed set of tools comparable in completeness to the Adobe Creative Suite offering.

Xeon is newer than P3, so it seems, in the spirit of Linux, I'd really better recompile my own kernal version. Will broaden my horizons too, I guess.


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