Maxtor 80-Gig 6Y080L0 - HowTo and Caveats

The idea behind this disk is great - 158816 cylinders, 16 heads, 63 sectors, all for 81964302336 bytes. The big number of cylinders should allow fine-grained partitioning, etc.

Practice is far from theory, as usual. When I installed this disk as a second drive in my box, it was baptised "hdd" (hdc being the previous disk), and the system hardware is now:

P4 2600 Mhz
512 Mb RAM
Toshiba SDR-1412T DVD/CD-RW (hda)
Epson R300 (Printer +USB Drive) (hdb)
WD HDS722580VLAT20 82-Gig (hdc)
Maxtor 6Y080L0 80-Gig (hdd) - OUR PATIENT

hdc is fully owned by Windows XP, hdd is dedicated to Linuxes - Xandros OC 3.0.1, Vector SOHO 5.0 and SimplyMepis 3.3.1 peacefully coexist there, sometimes helping one another.

When I connected the drive and fired up the Mepis Live CD, all was quiet, and nowhere there were even the slightest signs of trouble. I opened "cfdisk", read the disk parameters - cylinders, heads, sectors, bytes, - then closed "cfdisk", opened the old menu-driven "fdisk", and started carving partitions.

Why "fdisk"? By one simple reason - "fdisk" has the option to determine partition size in integer number of cylinders. I might sound conservative, but it just feels better when partitions start and end on cylinder boundaries.

The final partitioning looked this way:

hdd1 - 14.8 Gb primary
hdd2 - 1 Gb (for swap)
hdd3 - 14.8 Gb primary
hdd4 - all the rest to the end (extended)
hdd5 - 12.3 Gb logical
hdd6 - 12.3 Gb logical
hdd7 - 12.3 Gb logical
hdd8 - 13.5 Gb logical

Wrote partition table to disk (still under Mepis Live), fired up "cfdisk" again, looked at the partitions, then assigned types 82 and 83 as appropriate. Then got a mug of beer and pushed "Install Me" icon.

Mepis politely asked me where would I like to install the system, and suggested the bottommost partition hdd8. At that moment I did not see any difference, so I pushed OK. Swap partition hdd2 was suggested and OK-d as well.

Some 20 minutes and a beer mug later Mepis asked me where I would like to put GRUB. Suggestions were - MBR on hdc, MBR on hdd, boot record on hdd8, and not install at all.
I chose the boot record on hdd8, knowing from previous experience that I can invoke this GRUB from practically anywhere simply by "root (hd1,7)" "makeactive" "chainloader +1".

That's where the BIOS limitations showed their ugly face...

In order to keep XP as isolated from Linux as possible, I use GRUB on a floppy. Booting without the floppy brings me straight into XP, booting with the floppy brings up a GRUB menu, where I have a choice of partitions to boot. So I edited the "menu.lst" file on the floppy to include:
--------------------
title SimplyMepis 3.3.1 on hdd8
root (hd1,7)
makeactive
chainloader +1
--------------------
and rebooted the computer.

I saw GRUB menu, pushed "SimplyMepis 3.3.1 on hdd8", then "root (hd1,7)" lighted up on screen and...my box stopped responding. The collapse was so deep that even "Ctrl-Alt-Del" did not wake her up. Only forced power recycling brought my box back to senses.

Now, to make the long story short, GRUB uses BIOS to boot the indicated partiton. In doing so, it expects the CHS data on input (Cylinder, Head, Sector, not the LBA!!), and if the cylinder number doesn't fit into 16-bit short integer (65535), the system hangs...

In my case, only hdd1, hdd3 and hdd5 can be booted by GRUB (cyl #1, cyl #29601, cyl #60201), all the rest are UNBOOTABLE!

For now I have Xandros OC 3.0.1 at hdd1, Vector SOHO 5.01 at hdd3 and SimplyMepis 3.3.1 at hdd5. Fortunately, once any Linux is booted, it takes over the disk access from the BIOS. So I can use hdd6-8 as additional file systems, home, data, etc.

Morale of this fable: not all 80-Gig drives are created equal! Mind the number of cylinders, and don't exceed 2^16-1 for bootable partition.

Maybe in far future GRUB developers will take the disk access over from BIOS at earlier stages, then we will be able to boot any hard drive from any partition, but now - Linux fans, beware!

Best wishes.
BNK