2.5.40 etc and IDE HDisk geometry
I've noticed that the system's idea of the IDE disk geometry seems to have changed from 2.4.xx.
In particular, I've got my 40G HD on a Promise PDC20268 PIC, and find that the (logical) CHS is different, while the LBA sectors remains constant (and correct according to the HD label).
2.5.xx does have the right values in that CxHxS = LBA blocks, but fdisk and lilo get a bit stroppy about the partition boundaries that were created from the CHS that were generated under 2.4.xx, so I will have to patch them up.
Question is - what is determining that initial value that becomes the "logical" CHS, and does it matter?
The fdisk and friends man pages are a bit vague on this, cfdisk says "picking 255 heads and 63 sectors/track is always a good idea", but I find 2.4.xx uses nn/255/63, while 2.4.xx uses mm/16/63, and as I dual boot with win98, consistent partition table behaviour is important to me.
Advice anyone?
Aside - RedHat has dropped cfdisk from util-linux in their distro versions 7.2 ff. Given the bad words said about fdisk, what did cfdisk do to be ostracised?
Quoted 2 lines · Allan Duncan
Question is - what is determining that initial value that becomes the "logical" CHS, and does it matter?
No, it does not matter at all.
CHS are meaningless numbers not used anywhere anymore in Linux.
If you want to influence what geometry *fdisk will use, give it the appropriate options or commands. No need to go via the kernel. But only in rare cases is it necessary to worry about geometry.
Andries
Quoted 2 lines
Aside - RedHat has dropped cfdisk from util-linux in their distro versions 7.2 ff. Given the bad words said about fdisk, what did cfdisk do to be ostracised?
RedHat thought cfdisk is buggy.
They were mistaken.
Andries,
If CHS is truly meaningless (less drives smaller than 8.4GB) why can we not specify forced LBA geometry reporting? Also any drive supporting 48-bit feature sets are forbidden to use CHS.
Just a comment, not bait for a lesson or lecture :-)
Quoted 17 lines · Andries Brouwer
Quoted 2 lines · Allan Duncan
Question is - what is determining that initial value that becomes the "logical" CHS, and does it matter?
No, it does not matter at all.
CHS are meaningless numbers not used anywhere anymore in Linux.If you want to influence what geometry *fdisk will use, give it the appropriate options or commands. No need to go via the kernel. But only in rare cases is it necessary to worry about geometry.
Andries
Quoted 2 lines
Aside - RedHat has dropped cfdisk from util-linux in their distro versions 7.2 ff. Given the bad words said about fdisk, what did cfdisk do to be ostracised?
Quoted 8 lines
RedHat thought cfdisk is buggy.
They were mistaken.
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Andre Hedrick
LAD Storage Consulting Group
Quoted 6 lines · Andries Brouwer
Quoted 2 lines · Allan Duncan
Question is - what is determining that initial value that becomes the "logical" CHS, and does it matter?
Quoted 6 lines
No, it does not matter at all.
CHS are meaningless numbers not used anywhere anymore in Linux.If you want to influence what geometry *fdisk will use, give it the appropriate options or commands. No need to go via the kernel. But only in rare cases is it necessary to worry about geometry.
Like LILO. It complains that the partition tables don't match the geometry, or somesuch, despite an explicit "lba32".
Maybe I should start looking at grub, assuming it doesn't do the same.
Quoted 1 line · Allan Duncan
Like LILO. It complains
Maybe sufficiently recent LILO is OK.
Quoted 1 line
Maybe I should start looking at grub, assuming it doesn't do the same.
"lilo -R" is very useful. I don't think grub has that capability.
Andries
Quoted 2 lines · Allan Duncan
Like LILO. It complains that the partition tables don't match the geometry, or somesuch, despite an explicit "lba32".
If everything else is fine, and if this is one of the errors from the partition table checks, you could turn it simply into a non-fatal warning with the config option "IGNORE-TABLE".
- Werner
Signature · 3 lines
_________________________________________________________________________ / Werner Almesberger, Buenos Aires, Argentina [email protected] / /_http://www.almesberger.net/____________________________________________/