Wednesday, July 08, 2009

Booting a Server with a USB Key

There are numerous instructions on the internet for creating and booting a server with a USB key, but they were all complex or hard to read – even for a techy like myself.

So I thought I would rewrite a simple list of instructions to allow you to create a DOS bootable USB pendrive/key that you can use for any purpose (i.e. flashing BIOS's and other low level functions, as well as booting into other operating systems).

  1. Download download bootable_usb.zip from www.lowfps.com. This is the website these instructions are based on, but I wanted something clearer than that.
  2. Extract the download to a temporary location (i.e. C:\Users)
  3. Run the HP bootable media.exe program and install the software.
  4. Insert the USB key you want to use – it will get wiped during this process to backup its contents if needed.
  5. Run the HP USB Disk Storage Format Tool from the desktop or Start Menu. If you are using Vista or later then you will need to run the program in elevated mode (right-click program and choose Run as administrator).
  6. Select your USB key and choose to do format the key with the FAT or FAT32 file system. Choose Quick Format and select Create DOS Startup Disk. Pick the sub-option "Using DOS files located at" and select the same "DOS Files" subfolder in the location where you extracted the download too (C:\Users in my above example).
  7. Click OK. The USB key will be wiped during this process and a copy of the core files for Microsoft Millennium DOS will copied to the key.
  8. When complete copy to the key any files that you need to execute in DOS mode on the PC (for example I needed to update the BIOS on a x64 Windows Server 2008 Server Core installation running on a Dell Optiplex 755 and it said this was not allowed). The files you copy to the key must work in DOS though.
  9. Shutdown the server and insert the USB key. You must do a hard reboot, a restart will not work.
  10. Restart the server and press F12 to bring up the one-time boot menu (if you do not have this option then go into setup [Del or F2] and ensure USB booting is enabled and set to the primary option).
  11. In the boot menu choose the USB key option.
  12. From the C:\ prompt run the programs you need to start. Note that this is old style DOS and not the Command Prompt in later versions of Windows – so no command completion using the TAB key. So place the files in or near the root folder.

Friday, July 03, 2009

Windows Backup Failure on Windows Server 2008

I recently had a case where Windows Backup would fail at approx. 75% complete during a full backup. The backup utility and command line both reported that "The system cannot find the file specified". The Event Viewer/Application... Services/ Microsoft/ Windows/ Backup/ Operational reads "Backup target is running low on free space. Future backups to this target may fail for want of enough space." and then at the same time and immediately after that we get "Backup started at TimeZ' failed with following error code '2147942402'" which means file not found or unknown error.

After a series of email communications with the Windows Backup team at Microsoft India (where, incidentally, the program was developed) the answer came back that I should run chkdsk /r and reboot the server. As this process can take hours this occurred out of hours and actually in my case needed to be repeated twice. A normal chkdsk command, run whilst the server was online, reported that the disk had errors and could not continue.

After running chkdsk /r twice, from an elevated command prompt, the backup started to work again.