[syslinux] MEMDISK issue with OptiPlex GX280,620

Jason Vasquez jvasquez at kennesaw.edu
Fri Dec 10 17:28:20 PST 2010

Pardon my delay in responding. The past day had me reviewing the disk image being used - specifically, its geometry and its history.

Ghost imaging has long been an integral part of the environment here. With that said, relying on Symantec's Ghost Solution Suite's Ghost Boot Wizard to create a Network Boot Package in the form of an ISO and CD had been the way for years. Enter SYSLINUX and an available, local PXE server, and CD booting was migrated to a less-archaic method of imaging. The ISO produced from the Boot Wizard was not to be dismissed though. The ISO file contains a 24 MB disk image; one that is larger than I prefer and loading slower than desired. That image is, in effect, the source of my hacked/modded 8MB disk image. I need something larger than 4 MB but less than 24 MB.

Upon Shao's splendid advice of gzipping initrd and seeing the results, I have elected to start anew. I returned to the ISO (and its embedded 24 MB disk image) produced from the Symantec GSS Boot Wizard. After gzipping the disk image, I now have a ~6 MB file. Nicely, it loads rather quickly -  besting the 8 MB image.

Additional to this clean approach, the disk image's geometry is explicit. Based on yours and Gene's comments about disk geometry, I feel much better now having a sound disk image. Progress, agree?

Booting the new image though has changed little. Version 4.03 of MEMDISK (ISOLINUX and PXELINUX both invoked for testing), produced these results:


Ramdisk at 0x07f099000, length 0x005cc813
moving compressed data 0x07f099000 to 0x7d939a00
gzip image; decompressed addr 0x7df06400, len 0x01780800: ok
command line: initrd=images/ghostclient/280_620/osbootc.img.gz BOOT_IMAGE=memdisk
MEMDISK: Image seems to have fractional end cylinder
Disk is hd0, 24066 K, C/H/S = 2/255/63 (MBR/MBR), EDD on, rw
Using safe INT 15h access to high memory
Code 1744, meminfo 264, cmdline 70, stack 512
Total size needed = 2590 bytes, allocating 3K
Old dos memory at 0x9fc00 (map says 0xa0000), loading at 0x9f000
1588: 0xffff  15E801: 0x3c00 0x07cf0
INT 13 08: Success, count = 1, BPT = 0000:0000
We lost the last drive in our class of drives.
Drive probing gives drive shift limit: 0x01
old: int13 = f0005c6f  int15 = f000f859  int1e = f000efc7
new: int13 = 9f00000a  int15 = 9f0003ba  int1e = f000efc7
Loading boot sector... booting...
Starting PC DOS...

Again, Ghost is unable to see the internal SATA drive from this image's booted environment.

Reverting back to MEMDISK 3.83, the 'lost last drive' message does not occur and Ghost can see the SATA drive.

To reiterate, this image does not work on OptiPlex GX280s and GX620s via MEMDISK versions newer than 3.83. The image will work on the OptiPlex 755,780, and 980 systems via all MEMDISK versions post 3.83. And as much as a superfloppy might assist here, its 3840 KB capacity is generally inadequate.

If it helps, I could provide a copy of my image for personal testing and examination. If you're interested, please let me know how it would be best to deliver the ~6 MB image.

Thank you and Gene both for responding this week. Regards.

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