boltblog

Found this somewhere.
Works for me.

Section "ServerLayout"
	Identifier     "BodhiZazen's KVM xorg.conf"
	Screen      0  "Screen0" 0 0
	InputDevice    "Mouse0" "CorePointer"
	InputDevice    "Keyboard0" "CoreKeyboard"
EndSection

Section "Module"
	Load  "record"
	Load  "dri"
	Load  "extmod"
	Load  "glx"
	Load  "dbe"
	Load  "dri2"
EndSection

Section "InputDevice"
	Identifier  "Keyboard0"
	Driver      "kbd"
EndSection

Section "InputDevice"
	Identifier  "Mouse0"
	Driver      "vmmouse"
	Option	    "Protocol" "SysMouse"
	Option	    "Device" "/dev/sysmouse"
	Option	    "ZAxisMapping" "4 5 6 7"
EndSection

Section "Monitor"
	Identifier   "Monitor0"
	VendorName   "Monitor Vendor"
	ModelName    "Monitor Model"
	HorizSync       20.0 - 50.0
	VertRefresh     40.0 - 80.0
	Option          "DPMS"

EndSection

Section "Device"
	Identifier  "Card0"
	Driver      "vesa"
	VendorName  "KVM - std"
	BoardName   "GD 5446"
	BusID       "PCI:0:2:0"
EndSection

Section "Screen"
	Identifier "Screen0"
	Device     "Card0"
	Monitor    "Monitor0"
	SubSection "Display"
		Viewport   0 0
		Modes "800x600"
	EndSubSection
EndSection

Accidentally stumbled across the “Debian Cheat Sheet” at http://carlo17.home.xs4all.nl/howto/debian.html (now dead – see pdf below)

Finally some documentation on why the heck pinning with “Package: *” and “Package: mypackage” doesn’t mix well, and other useful knowledge.

In case the link goes dead, here’s a PDF: debian_cheat_sheet.pdf

This was blatantly stolen from technovelty, kept here because I hate it when my bookmarks die.

For some reason, people seem to get this quite wrong a lot of the time. Certainly one should not be playing with symbols that start with __ unless you really know what you’re doing with them.

ianw@lime:~/tmp/override$ cat override.c
#define _GNU_SOURCE 1
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <dlfcn.h>

pid_t getpid(void)
{
        pid_t (*orig_getpid)(void) = dlsym(RTLD_NEXT, "getpid");
        printf("Calling GETPID\n");

        return orig_getpid();
}

ianw@lime:~/tmp/override$ cat test.c
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

int main(void)
{
        printf("%d\n", getpid());
}

ianw@lime:~/tmp/override$ gcc -shared -fPIC -o liboverride.so override.c -ldl
ianw@lime:~/tmp/override$ gcc -o test test.c
ianw@lime:~/tmp/override$ LD_PRELOAD=./liboverride.so ./test
Calling GETPID
15187

In my raid setup, I set up the partitions a certain way for running several mdadm raids on the same drive.

My server currently boots off of two drives, sda and sdb, where sda1 and sdb1 are the root file system in raid 1 (mirror) and sda2 and sdb2 are (encrypted) swap in raid 0 (striped). This is useful to have the redundancy of raid for booting, but none of that redundancy for the volatile swap partition. Instead I get higher write speed, which is always a bonus.

Note: Most Linux distros would actually stripe the swap anyway, given two swap partitions with equal priority, but I chose to do it this way.

Anyway, when one of the drives went for a one-way trip to electronic oblivion, the need arose to configure my new drive exactly as the old ones. Mind you, mdadm can actually handle non-equal partition sizes in a raid, but I’m kind of anal about this.

sfdisk to the rescue!

First, of course, I replaced the faulty drive (sdb) with one of the same brand and equal size. You don’t necessarily need the same brand, but that’s what I had.

Then, to export and save the partition table from sda (which was still working)

sfdisk -d /dev/sda > sda_partitions

..and save it to the replaced sdb

sfdisk /dev/sdb < sda_partitions

You can also do it all in one go

sfdisk -d /dev/sda | sfdisk /dev/sdb

As usual, RTM for more options 🙂