Author Topic: AOS RAM Disk  (Read 13203 times)

Andy Willis

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Re: AOS RAM Disk
« Reply #15 on: September 26, 2018, 03:41:40 am »
You can put the swap file there too and in theory run a bunch of processes that use lots of memory and it would swap. In practice, IBM seems to have used 32 bit variables in too many places for this to work.
I put my swapper.dat on the RAM disk just so that it wasn't writing to the SSD drive every boot but given we can't use over 4G I don't see how the swapper could ever be used.

Dave Yeo

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Re: AOS RAM Disk
« Reply #16 on: September 26, 2018, 04:53:50 am »
What happens if you start up 5 processes that each use a GB of memory?
In theory you should just get some swapping but as I mentioned, OS/2 seems to use 32 bit variables that limit the size of virtual memory. The swap file itself is limited by using signed 32 bit based on what happens if you grow it more then 2GB (same thing as if you run out of disk space) based on experience. It makes sense as all file systems had a 2GB file limit before JFS.
The i386 is quite capable of  handling 16 TB of virtual memory IIRC, but only 4 GB of address space

Valery Sedletski

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Re: AOS RAM Disk
« Reply #17 on: September 26, 2018, 01:38:28 pm »
I always thought, it is a 4 GB, not 4 MB limit. Am I not right?
You may not be right indeed: https://en.wikipedia.org/wiki/Gibibyte... :P

I don't use term "GibiByte". It is not "real" term. I use only real term "GigaByte". 1000 MB is not a gigabyte. Gigabyte was always 1024 Megabytes.