Nov 022018
 

See previous article to understand why and what.

Previously we have created our differencing / child disks.

Lets first set our iscsi target with Starwind San Free by creating two targets and attaching one disk in each target.





Then lets boot our diskless computers over the network with TinyPXE Server.

We will use the below ipxe scripts (one for each network booting computer).
Replace ‘X’ below with the target number (1 or 2) on line 3 and 5.

#!ipxe
clear net0.dhcp/gateway:ipv4
set initiator-iqn iqn.2006-11.X
set keep-san 1
sanboot --keep iscsi:${next-server}:tcp:3260:0:iqn.2008-08.com.starwindsoftware:erwan-pc2-childX

And here we go, we have X diskless computers booted over the network using differencing disks on the iscsi target.

 Posted by at 19 h 23 min
Nov 022018
 

Windows server iscsi target is a nice product allowing one to boot diskless computers over the network (using iscsi).

Furthermore, windows iscsi target supports differencing virtual hard disks (vhd) allowing one to build a « master » (parent) disk and then create differencing disks thus leaving the master disk untouched.

But you dont always have a windows server at hand and you may wish to go for a cheaper alternative, or just do it another way for fun 🙂

The next 3 articles will take you on a journey to achieve the above i.e boot diskless computers over the network (using StarWind San Free and TinyPXE Server) with differencing virtual hard disks:

create the master / parent disk
create the differencing / child disks
boot diskless computers over the network using these child disks

 Posted by at 13 h 45 min
Sep 012018
 

Some weeks ago, I did buy this nice new drone Aurora mini fight BNF at Gearbest for a very competiting price.
During the order, you had to specify the radio protocol (flysky, frsky, dsmx, etc …).
Since I own a flysky i6 remote controler, I obviously went for flysky.
So far so good.

Unfortunately Gearbest shipped a DSMX version which I obviously cannot fly.
Very disapointing but as I have ordered lots of items on similar chinese sites, I did not panic and was pretty sure I could find a good way out with Gearbest : refund a new receiver, ship a new receiver, etc …

To my big surprise, after many attempts to explain / prove / demonstrate the issue thru pictures, Gearbest has proven to be extremely incompetent or mishonest and ended with the below (ticket opened on August 8th – item ordered on July 5th).

So my best advice if you are a drone guy : dont buy your stuff there.
These guys dont know what they are selling and wont be able to support you in any matter.

FYI : I thought I was a smart ass find this pun « gearworse », well it looks like i am not the first one : gearworse

« 

Juin 172018
 

Been playing with the excellent strarc from Olof.

The basics first:
-to backup a drive/folder to an archive: strarc.exe -cd:C:\ Z:\winxpsp3.sa
-to restore a drive/folder from an archive : strarc.exe -xd:C:\ Z:\winxpsp3.sa

Then, one can backup all files from one logical drive to another (on XP) in one go with this command : strarc.exe -crjd:c:\ | strarc.exe -xd:d:\.
Note the r parameter which will take care of loaded registry hives.
Ideally, rather than backuping a « hot » logical disk (i.e in used), you would use a Volume shadow copy as source (see a discussion here).

Dont forget that when you decide to backup files (i.e not a full physical disk), you need to take care of the MBR on the target disk (hint : grub4dos) and ensure that registry hives are included.

You can also perform such a backup over the network:
-On the « server / host A » side : nc -v -l -p 9000 -e « strarc -cd:x:\my_folder\ »
-On the « client / host B » side : nc 192.168.1.1 9000 > dump.sa (update the IP obviously with your « server » IP).

Host B will connect to host A (listening on port 9000) and dump all received data (from Host A) to dump.sa

 Posted by at 13 h 22 min  Tagged with:
Fév 032018
 

A native app is an app that will be launched as soon as the kernel initialization is completed.

It will be launched (in user mode) by the session manager (smss.exe) thru the registry key HKLM\SYSTEM\CurrentControlSet\Control\SessionManager\BootExecute(run at every boot) or HKLM\SYSTEM\CurrentControlSet\Control\SessionManager\setupexecute(run once only).

A native app can only use NT API functions (ntdll.dll) and not the Windows API functions.

Possible usages :
nativereg createkey \Registry\Machine\SYSTEM\Setup key1
nativereg createvalue \Registry\Machine\SYSTEM\Setup\key1 test0 8 REG_RND_SZ
nativereg createvalue \Registry\Machine\SYSTEM\Setup\key1 test1 toto REG_SZ
nativereg createvalue \Registry\Machine\SYSTEM\Setup\key1 test2 112233AABBCC REG_BINARY
nativereg createvalue \Registry\Machine\SYSTEM\Setup\key1 test3 666 REG_DWORD
nativereg deletevalue \Registry\Machine\SYSTEM\Setup\key1 test1
nativereg deletekey \Registry\Machine\SYSTEM\Setup\key1

The tool is 32 bits (a 64 bits may come later).
It works on XP and up.

Discussion here.

Regards,
Erwan

Jan 082018
 

If like me you have an old computer and dont want to install the Ubuntu update for Meltdown and Spectre ubuntu update :

  • sudo vi /etc/default/grub
  • add nopti to GRUB_CMDLINE_LINUX_DEFAULT (there should be a list of parameters already like « nomdmonddf nomdmonisw nomdmonddf nomdmonisw »)
  • sudo update-grub
  • sudo reboot

check that nopti is there with cat /proc/cmdline

Mai 062017
 

Under some specific circumstances, it might be handy to run as system.
RunAsSys will launch a process as the local system account.
This require local admin rights.

Download it here.

 Posted by at 16 h 21 min
Déc 282016
 

Been a while since last article.

A quick one to post a tool I have been using lately to quickly convert VMDK to raw disks.
Indeed it is sometimes easier/quicker to install an operating system in a virtual environement but afterwards you may want to convert the vmware disk (vmdk) to a raw disk so that you can write it to another physical media (usb, hard drive, etc).

Thanks to libvmdk, a library written by Joachim Metz, it is easy to write a quick graphical frontend that will read a vmdk and write it back to a raw image.

VMDK2RAW can be downloaded here.

Erwan

 Posted by at 0 h 42 min  Tagged with: