PAE error with 4GB memory

Discussion in 'Parallels Workstation for Windows and Linux' started by tracer999, Oct 17, 2006.

  1. tracer999

    tracer999 Bit poster

    Messages:
    3
    I am running Ubuntu Edgy, kernel 2.6.18 (needed to compile myself). I have 4GB memory, but needed to enable 64GB support in the kernel in order for the last 1GB to be recognized. I have a Core 2 Duo.

    When I try to start a virtual machine I get this error:

    Parallels Workstation experience problem when trying to allocate physical memory in PAE mode. The current version of Parallels Workstation supports up to 4 GB of physical memory. To fix the problem you have to change the auto detected memory size to 4096MB. Add to your boot loader the following option "mem=4096M".

    I tried setting the boot parameter as requested but this did not fix the problem. I tried changing the amount of memory available to all virtual machines, and the amount of memory set for my XP virtual machine (it was 256MB). None of these fix the problem.

    Any way to fix this issue?
     
  2. David Corrales

    David Corrales Hunter

    Messages:
    189
    Does the problem happen with the regular 2.6.17-generic kernel?
     
  3. tracer999

    tracer999 Bit poster

    Messages:
    3
    David - I just tried 2.6.17-generic and the problem does not happen (it runs correctly). However, when running with this kernel I only have 3GB available. Machines like mine (a Dell Dimension 9200 and similar) need CONFIG_HIGHMEM64G=y in the kernel since the last 1GB is mapped above the 4GB space. To compile the kernel I used the vanilla 2.6.18 kernel, the same .config settings as 2.6.17-generic, with the one change (CONFIG_HIGHMEM64G=y).

    I realize the kernel is slightly non-standard, but I think a lot of people will soon be in the same situation as me with similar hardware.
     
  4. David Corrales

    David Corrales Hunter

    Messages:
    189
    Why don't you just recompile the generic kernel and change that option? That way you get a fully functional kernel along with 4Gb ram.
     
  5. tracer999

    tracer999 Bit poster

    Messages:
    3
    Hello - I tried this suggestion. I compiled 2.6.17-generic with only that one option set - I changed the memory setting from 4GB to 64GB. This changed to kernel options:

    CONFIG_HIGHMEM4G=y <-- this was removed


    CONFIG_HIGHMEM64G=y <-- this was added
    CONFIG_X86_PAE=y <-- this was added


    Using this kernel does not fix the problem. I still can't run parallels and get the same error.

    I tried booting again with mem=4096M as a boot option and I was able to run parallels. However, this limits the system to 3GB system memory:

    $ head /proc/meminfo
    MemTotal: 3114808 kB
    MemFree: 1823308 kB
    Buffers: 19384 kB
    Cached: 948392 kB
    SwapCached: 0 kB
    Active: 854372 kB
    Inactive: 318812 kB
    HighTotal: 2226636 kB
    HighFree: 1056800 kB
    LowTotal: 888172 kB


    Is there any way I'll be able to get this to work with PAE and be able to use all physical memory on the machine (4GB)? Using PAE and HIGHMEM64G apparently is the only way to get linux to recognize 4GB on these dells.
     
  6. kelobro

    kelobro Member

    Messages:
    25
    I have the same problem.

    I wasted xmas day trying to use the x86_64 kernel with 32bit libraries. Tonight, I will go back to gentoo i686 build and give the kernel the mem=5G parameter. This might be your solution too. If you are running a 32 bit kernel already, give it a try. If it doesn't work, you'll save me some time.

    sidenote -- I wish I hadn't gone for the AM2 processor with it's DDR2 memory. I could have swapped 2x512 dimms out of a G5 and the AMD server if I had gone 939 instead. I'm not happy with the idea of removing a GB of RAM and having nothing to put it in. If anyone out there wants to swap 2x1GB PC3200 modules for 2xDDR2-800 modules send I private email. I may consider if I cannot get the 4GB of RAM working in the AMD server. You PC3200s would have to work in a Mac G5 though (corsair don't play that way for sure).
     
  7. ksenks

    ksenks Parallels Developers

    Messages:
    164
    4G RAM is not supported in Parallels Workstation 2.2.
    Please limit your RAM to max - 3,6G.
    We are aware of such problem and working on the update.
     
  8. kelobro

    kelobro Member

    Messages:
    25
    Any status on this? Seems to me you guys need to focus on the PC limitations and problems before spending time on the compressor server. With the release of VMWare's Fusion beta for Mac I am very close to giving up on Parallels.

    My |ssues:

    Can't use 4GB of RAM on 32bit linux host OS.
    Can't use Parallels on a 64 bit linux host OS at all.
    Can't setup networking the way I need it to work on my windows XP Laptop:
    • Must have "host only" Parallels network.
    • It must not register new MAC Addresses on the LAN. This confuses the network admins.
    • Must be able to access the internet from the "host only" network via NAT through windows XP
    • It must play nice with the Cisco VPN software or at least be managable.
    • Support should not be via forum only. I have never seen a response to my emails.
     
  9. linhgb

    linhgb Bit poster

    Messages:
    2
    Hi, is there any update on this? It's been over 2 months.

    My system has 4GB of RAM running Ubuntu Edgy 2.6.17-11-generic kernel (stock) and it is already limited to 3.6GB:

    Code:
    $ free -m
                 total       used       free     shared    buffers     cached
    Mem:          3546       3418        127          0        226       1911
    -/+ buffers/cache:       1280       2265
    Swap:         1906          5       1900
    $ cat /proc/meminfo
    MemTotal:      3631352 kB
    MemFree:        130492 kB
    
    I get the same error as trace999 the thread starter.
     

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