Running FBA on the Bootable CD-ROM Run-Time Image

Article
10/07/2008

To boot an El Torito run-time image on a hard disk, a CD-ROM with a copy of the run-time image is required. When you boot the run-time image, this CD-ROM is used to identify and mount the CD-ROM drive during the First Boot Agent (FBA) phase. Also during this phase, the Enhanced Write Filter (EWF) starts and creates the EWF Volume.

To run FBA and validate the status of EWF

Verify that the pre-FBA El Torito CD-ROM is inserted into the device CD-ROM drive.

Note You can use any previously created El Torito CD-ROM to identify and mount the CD-ROM drive during the FBA phase provided the disk signature and partition sizes have not changed. During FBA, the system matches the disk signature specified in the El Torito component setting and the partition size of the run-time image. Unless you change the default value of either of these settings, you can use any previously created El Torito CD-ROM disks.
Boot the run-time image located on the 650 MB hard disk partition.

FBA automatically starts.

The Eltorito.sys driver detects, reports, and sets up the new disk volume during the Plug and Play enumeration phase in FBA.

With EWF, FBA usually reboots the system twice before it has completed its process and you can view the shell.

After FBA completes, log on to the system and validate the status of EWF by using Ewfmgr.exe. The following list shows the steps to take to validate the status of EWF:

Verify the status for EWF volume configuration by typing ewfmgr. For details, see EWF Volume Configuration. If EWF is configured correctly, Ewfmgr.exe displays the status of the EWF volume. The following example shows the status.

Ewf Volume Configuration
Volume Size            681574400
Segments               8192
Segment Size           249856
Free segments          8192
Max Levels             1
Max Protected Volumes 1
Protected Volumes      1
Overlay volume percent full 0.00
Protected volumes
Arc Path "\Device\HarddiskVolume1"

Verify the status for protected volume configuration by typing ewfmgr c:. For additional information about EWFMGR, see EWF Manager Commands. The EWF manager console application displays the status of the protected volume. The following example shows the status.

Protected Volume Configuration
Type            RAM
State           DISABLED
Boot Command    NO_CMD
  Param1        0
  Param2        0
Persistent Data ""
Volume ID       D2 02 96 49 00 0E 59 96 02 00 00 00 00 00 00 00
Device Name     "\Device\HarddiskVolume1"
Max Levels      1
Clump Size      512
Current Level   1
Disk space used for data 0 bytes
Disk space used for mapping 0 bytes
Memory used for mapping 0 bytes

If either of these commands displays an error message, verify that EWF is configured correctly. To troubleshoot, read the FBA log file, Fbalog.txt, in the FBA subdirectory. The FBA log should contain EWF information at the end of the file. An example of FBA log information is shown in the following example.

ConfigureEwf() Start.
Getting EWF config parameters from registry.
EWF Partition Size = 0 (KBytes), Levels = 1, Volumes = 1.
Protected Volume Config #0 :
  Disk= 0,Part= 1,DiskType= IDE,Type= RAM.
  Enable= Disabled, Optimize= 0, LazyWrite= N.
Found 2 Hard Disks.
Searching for El Torito disk.
Disk0 signature = 0x499602D2.
Disk1 signature = 0x4F544C45.
Disk1 is an ElTorito disk.
Disk #0 layeout info:
PRIMARY partition,start=0x00000001966dfa00, len=0x0000000025429800, type= 6
Created EWF partition on Disk = 1, partition = 1,size = 0x0000000000007e00 .
Saving EWF configuration to registry:
Protected Volume ArcName = multi(0)disk(0)rdisk(0)partition(1).
ewfOpen.
EWF Volume Config on Disk#1, Partition#1:
  Segments = 0, Max Volumes = 1, Max Levels = 1
ewfAdd.
Protected Volume Config on Disk0\Partition1 :
  Type = RAM, State= DISABLED.
ewfClose
ConfigureEwf() End, status = 0x0.

If the status in the configureEwf() End statement is not equal to zero, look for error messages in the EWF log section.

For help resolving EWF problems, see Troubleshooting Enhanced Write Filter.

For more information about Ewfmgr.exe, see EWF Manager Commands.

In Logical Disk Manager, verify that your target system contains the El Torito CD-ROM and the original disk from which you booted your target system. If it does not, read the FBA log file and verify that the El Torito CD drive was listed in Plug and Play by searching for the "Eltorito\eltoritodiskdevice" string. If the El Torito CD drive is not listed, configure the Enhanced Write Filter component to include it, and then run FBA again.
If EWF is functional and the El Torito CD drive has been listed in the FBA log file, you can customize the run-time image by adding additional applications and configurations.

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Running FBA on the Bootable CD-ROM Run-Time Image

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