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Re: Debian 9 running (extremelly) slow




Hi,

my only theories for now are that your attempts with Debian 8 and 9
differ in respect to processor architecture (32 vs. 64 bit) and/or that
you don't have enough RAM to avoid heavy swapping during installation.

(Consider to subscribe to this list in order to see answers.)


Alexandru Iancu wrote:
> https://h10057.www1.hp.com/ecomcat/hpcatalog/specs/provisioner/05/GA009ET.htm

How much RAM does yours have ?
What processor "arch" of Debian did you install with Debian 8 and 9 ?
(amd64 or i386 ?)


> ASLR seems like something could
> affect large number of/every executable

According to Wikipedia this is already in Linux kernel 3.14. Debian 8
(two years ago) installed 3.16 for me.

> https://insights.sei.cmu.edu/cert/2014/02/differences-between-aslr-on-windows-and-linux.html

This points to PIE and mentions that "x86_64" (aka "amd64") is less
affected than "x86" (aka "i386", 32 bit).
PIE usage is indeed supposed to have grown in Debian about a year ago:
  https://wiki.debian.org/Hardening/PIEByDefaultTransition

But i guess that if RAM is in short supply, it may still be more efficient
to use "i386" because its programs usually have a smaller memory footprint.
On the other hand, PIE is said to work better on "amd64".


> is it possible to disable this security feature ?

You would have to compile the affected binaries from their sources.
Assuming that it is about PIE and not ASLR, you'd not need a new kernel,
but rather new userland programs which where built without compiler and
linker options like -fPIE or -pie.

In order to verify your theory, you could chose a program which shows
a well measurable slowdown on Debian 9 but has few libarary dependencies.
First you would check whether it helps to only compile and link the
program. If this does not bring speed, one would have to build all
necessary libraries without memory randomization.
Not an easy task, of course.


Have a nice day :)

Thomas