After a thorough discussion with Google we couldn't consent on this one.

How can I shrink the Hibernate partition which was set up by Windows 7 OEM? My laptop has a harddisk drive and an additional SSD drive (20GB) which is used entirely by this hibernate partition (it's an Ultrabook, so I believe there are also some Intel drivers for quick waking up).

I want to add dual boot with an Ubuntu and I'd like to give some of this space to Ubuntu as swap disk too.

While under Win7 the partition manager can't touch this partition, GParted sees it as a raw partition.

I'd like to shrink it so that Win can still use it as before (just smaller) and that Linux will use it for swap.

Can this be achived?

Note: I'm trying not to wipe the partition and recreate because I'm thinking that the OEM stuff are there, on this partition. Or am I wrong?


Like Indrek suggested, this partition is probably a SRT cache. And SRT is done using RAID, so I think the entire drive is used.

  • 2
    I doubt that partition is used for hibernation - it would have to be visible and accessible in Windows for hiberfil.sys to be able to live on it. Plus 20 GB is a bit excessive, since your ultrabook most likely has only 4-8 GB of RAM. It's more likely that the SSD is used as a cache for the hard drive, a technology called Intel SRT. What's your laptop's exact make and model?
    – Indrek
    May 23, 2012 at 13:25
  • @Indrek: I've seen laptops that have hibernation as part of the firmware and require a dedicated partition to avoid filesystem parsing (although those were from Win9x times). May 23, 2012 at 13:31
  • Isn't C:\huberfil.sys meant for hibernation..? Anyway, Linux uses a swap filesystem or file, Windows has a differet kind of filesystem (?) or file for that.
    – RobinJ
    May 23, 2012 at 13:39
  • @Indrek: I think you are right. It's an Acer Aspire S3-951-2464G34iss May 23, 2012 at 13:44
  • @RobinJ: That is why I intended to make 2 separate partitions May 23, 2012 at 13:45

2 Answers 2


If the partition isn't usable in Windows (ie. isn't formatted as a filesystem that Windows can read and write), then it can't be used for hibernation, because Windows cannot place the hiberfil.sys file on it. Also the size of the SSD is a bit excessive, given that the hibernation file need not exceed the amount of physical memory you have, which is probably around 4-8 GB.

Given that, it's much more likely that the SSD is used as a cache for the main hard drive, to speed up access to frequently used files and programs; this is known as Intel Smart Response Technology, though it may also be some sort of proprietary implementation by Acer.


Yes, there is few information on this topic. Lenovo also uses this hibernation partition on SSD for their "30-days sleep" option. The system goes into hibernation after sleeping 3 hours when on battery. Works in combination with Lenovo Power Manager and Thinkpad BIOS. Have a look at http://support.lenovo.com/en_US/downloads/detail.page?DocID=HT074526.

I found such a 0x84 partition on the mSATA SSD of my Thinkpad S430 that addionally contained a partition for caching the OS HDD using ExpressCache. I tried to find some information how to bring Windows to use this partition as a replacement for hiberfil.sys. It looks like that this 0x84 method is a third way - the OEM way - Windows diskpart lists this partition type as "OEM".

I doubt that this "30-days sleep" (instant on) option is still needed when the OS sits on a real SSD. It makes sense when the SSD is used as cache for a huge primary HDD disk.

I am going to replace the factory 16GB mSATA SSD with a 128GB model and install the OS on this and use the HDD for data - maybe I can partition the SDD in a way to use it as primary boot partition for W7 and additionally for caching the HDD?

Lenovo stated a warning in their hardware manual to not use the mSATA port for a boot disk but the support line told me that I can use the mSATA in any way I want to.

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