Installing OS on RAM disk?

Discussion in 'Operating Systems' started by BLEH!, Sep 12, 2013.

  1. BLEH!

    BLEH! Ancient Guru

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    Hey Gurus.

    Since I'm hopefully upgrading to an X79 system very soon which supports stupid memory bandwidth and vast amounts of RAM, a thought occurred to me: it's possible to install certain programs/put web cache on a RAM disk, but what about an OS? Say mirror it from an SSD during boot and dump it straight to RAM. Speeds would be insane.

    Any thoughts on how this could (if at all) be done?

    Ta

    BLEH!
     
  2. Extraordinary

    Extraordinary Ancient Guru

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    The OS is loaded to RAM anyway more or less, hence what you see using your RAM when you have just booted up and loaded nothing else
     
  3. BLEH!

    BLEH! Ancient Guru

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    True, in effect I guess I mean mirroring the OS onto a RAM disk and using that for application access.
     
  4. Extraordinary

    Extraordinary Ancient Guru

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    Not sure if it would work, but you could try creating a VMware VM and saving the virtual HDD to a RAM disk

    If it worked, that would give you an idea of the speeds I suppose
     

  5. BLEH!

    BLEH! Ancient Guru

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    Might be worth a try. Need my new rig and 64 GB RAM first :D
     
  6. Pill Monster

    Pill Monster Banned

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    Can't be done, at least not permanently.

    Besides, an OS loaded into memory is like a ticking time bomb. If you breathed on your ram too hard it might crash the whole system.

    SSD's are plenty fast though....
     
    Last edited: Sep 12, 2013
  7. mbk1969

    mbk1969 Ancient Guru

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    Well. If you will develop your own loader...
     
  8. drbaltazar

    drbaltazar Banned

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    It can ! but why bother ? if you disabled paging executive in regedit and disabled page file , everything relevant is already in ram.and with dca ? ROFL . its like wanting to go the speed of sound ! why you already go to the speed of light ! ramdisk might be nice for ****** , gaming (real time stuff) but it is very situational !
     
    Last edited: Oct 5, 2013
  9. mbk1969

    mbk1969 Ancient Guru

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    Do you know how "Say mirror OS from an SSD during boot and dump it straight to RAM" ?
     
  10. Pill Monster

    Pill Monster Banned

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    Touché :D
     

  11. BABA-The Hacker

    BABA-The Hacker Banned

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    ...all depends upon the application ( the author...how he or she developed it- ) { forget not _ Von -Neumann Architecture}...
     
  12. alanm

    alanm Ancient Guru

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    With custom made OS images it can be done (not installing into ram, but loading into it) as is done a lot on USB bootable flash drives. I use a Windows 7 PE bootable flash drive with recovery, partition, diagnostic and imaging tools. Using grub4dos boot loader pointing to Win 7's bootmgr (+ modded bcd file, boot.sdi which creates a ram disk to hold WIM files, ie, boot.wim), you can do it. But it has limitations, memory cannot hold changes or user settings. There are ways around that in which you can place certain programs where changes may occur outside of the boot.wim file (the part that holds the OS and is loaded into RAM) and the changes take place in ini files or reg scripts that write to the registry once the boot.wim is loaded.

    I have a lot of fun doing this on USB flash drives. The beauty of it is that the boot.wim image file (in source folder on Win7 install DVD/ISO) can be mounted with tools and modified/ slimmed down and configured with whatever tools you may want to include in it. Usually I keep it slimmed down to ensure fast loading into ram and thus a fast boot process. The configurable programs/files are outside of the wim file. Theres a forum, reboot.pro which specializes in that and has all the tools to get started.

    It can also be done on an HD in the same way as flash drives, but again, limitations if on a permanent basis. And whatever performance gains you may think you get are not much more noticeable vs an OS on SSD. Yes, you will get crazy ram drive speeds on HD Tune, but not much else. And as stated, much of an OS's functional parts are already loaded into ram anyway.
     
    Last edited: Sep 27, 2013
  13. Pill Monster

    Pill Monster Banned

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    ^That's why I said "not permanently", plus DOS is still needed to load grub anyway...

    These guys above are asking about loading and running the entire OS into memory.....dunno how you'd do that.
    And yeah some parts drivers/dll's whatever are cached but I wouldn't say it was very much or even a lot...just look at your cached memory amount in TM....with PF and SF disabled it's maybe 1.5GB or so?

    I mean technically sure yes but in practical terms, no.
     
  14. alanm

    alanm Ancient Guru

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    Yeah I know, which is why I said "custom" OS images. Grub4dos is a universal boot loader that can virtually boot from any environment (DOS, linux, windows and almost any media), it just exits to dos on errors or incorrect syntax.
     
  15. mbk1969

    mbk1969 Ancient Guru

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    Well, I was thinking not about RAM disk, but about something like loading disk sectors into RAM and then loading OS from these preloaded sectors. Such implementation would require custom loader + custom drivers (either disk, partition, volume).
     

  16. Pill Monster

    Pill Monster Banned

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    Yes it comes with UBCD...I've used it a couple of times....quite good.
    Tbh anything is better than MS DART which like most M$ diagnostic tools is inadequate. It's hardly even been improved since the ERD Commander days....just supports new OS's and that's about it.....

    Oops I'm ranting now....:nerd:
     
  17. drbaltazar

    drbaltazar Banned

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    I stand by my suggestion!
    Disable paging executive in regedit (to prevent paging,since you are gona disable paging file)and disable paging file!
    I would not go at it the ramdisk way ! Too many potential issue ! and like I said everything relevant will be In Memory anyhow by disabling paging file . I have yet to find a use for ramdisk . its like paging file : the only use I could see out of it is it probably used by NSA prysm etc . rofl ! OK I don't need that !
     
    Last edited: Oct 5, 2013
  18. Pill Monster

    Pill Monster Banned

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    Well with no PF nothing gets paged to disk anyway, so paging exec doesn't need to be disabled....
    I agree with you though on RAMdisk, not useful with todays hardware (64bit OS, tons of ram and SSD's). I don't care what benchmark scores people are getting.....

    There was a time it could be beneficial but just like the pagefile, it's no longer needed.....even with servers the amount of ram needed for caching would be colossal.....
     
  19. mbk1969

    mbk1969 Ancient Guru

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    Are you sure that without page file paging is off completely? All PE files act as page file for themselves (i.e. they don`t need pagefile.sys) through memory mapping API. And also in the Russinovich`s "Windows internals" stated that windows file cache acts through the same memory mapping API (i.e. pages are written and read)...
     
  20. Pill Monster

    Pill Monster Banned

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    No it doesn't disable paging instead all pages are kept in ram.....
    Obviously the drawback is virtual memory takes up ram so those with 4GB may run out of address space before running out of physical memory......but hey ram is cheap. lol Well it was till Hynix had a "fire".

    On a side note I wish people would stop quoting Mark like he was an IT God.....some of a his philosophies are quite outdated and not always accurate.
     
    Last edited: Sep 28, 2013

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