Re:Re: Filesystem type unknown...Debian

[BoB KoT]

Howdy,

>> /dev/hde5            63    204862    204800 
>> /dev/hde6        467007    598078    131072 
>> /dev/hde7        204863    467006    262144 
> I assume that what the BIOS detects as hd0 is what Linux identifies as the
> /dev/hde (Is this right ?).

Yes, exactly!!!

> What I do not understand with your example is that you tried (hd0,4) that is
> /dev/hde5, and (hd0,6) that is /dev/hde7, both without any file system (see
> above).

Perhaps a little more clarification will help.
This Abit Kt7-Raid mother board has 4 IDE drive connectors
The *only* hard drive in this system is physically connected as
ide2: master and thus becomes BIOS drive 0

                       Linux       FreeBSD    Grub
UDMA66  ide0: master  /dev/hda    /dev/ad0
              slave   /dev/hdb    /dev/ad1
UDMA66  ide1: master  /dev/hdc    /dev/ad2
              slave   /dev/hdd    /dev/ad3
UDMA100 ide2: master  /dev/hde    /dev/ad4    (hd0) 
              slave   /dev/hdf    /dev/ad5
UDMA100 ide3: master  /dev/hdg    /dev/ad6
              slave   /dev/hdh    /dev/ad7

So with only one physical drive in this system we have
  Linux     FreeBSD     Grub
  /dev/hde  /dev/ad4    (hd0)

Now let's move on to how that is partitioned
The output of sfdisk -l -x -uS /dev/hde that was in my 1st
post could be more clearly explained as follows. Note
that all the sector bounds of hde5 thru hde8 are between
the start and end of hde1. Likewise for hde2, hde3, hde4 

                    Start       End  #sectors  Id  System
/dev/hde1              63   5631695   5631633  a5  BSD/386
  /dev/hde5            63    204862    204800 
  /dev/hde6        467007    598078    131072 
  /dev/hde7        204863    467006    262144 
  /dev/hde8        598079   5631695   5033617
/dev/hde2         5631696  11775455   6143760   5  Extended
  /dev/hde9       5631759   5660927     29169  83  Linux
      -           5660928   6160895    499968   5  Extended
      -           5631696   5631695         0   0  Empty
      -           5631696   5631695         0   0  Empty
  /dev/hde10      5660991   6160895    499905  82  Linux swap
      -           6160896  11775455   5614560   5  Extended
      -           5660928   5660927         0   0  Empty
      -           5660928   5660927         0   0  Empty
  /dev/hde11      6160959  11775455   5614497  83  Linux
      -           6160896   6160895         0   0  Empty
      -           6160896   6160895         0   0  Empty
      -           6160896   6160895         0   0  Empty               
/dev/hde3        11775456  18955439   7179984  a5  BSD/386
  /dev/hde12     11775456  12037599    262144 
  /dev/hde13     12037600  12299743    262144 
  /dev/hde14     12299744  18955439   6655696
/dev/hde4     *  18955440  60036479  41081040  a5  BSD/386
  /dev/hde15     19217584  19479727    262144
  /dev/hde16     19479728  20004015    524288 
  /dev/hde17     18955440  19217583    262144 
  /dev/hde18     20004016  60036479  40032464

Now that we are convinced of these relationships I'll drop the sector
numbers. The mappings related by LBA sectors are as follows:

  Linux            FreeBSD       Grub       Mount    ID   
/dev/hde1      /dev/ad4s1      (hd0,0)              0xa5  BSD/386
  /dev/hde5      /dev/ad4s1a     (hd0,0,a)  /
  /dev/hde6      /dev/ad4s1b     (hd0,0,b)  swap
  /dev/hde7      /dev/ad4s1e     (hd0,0,e)  /var
  /dev/hde8      /dev/ad4s1f     (hd0,0,f)  /usr
/dev/hde2      /dev/ad4s2      (hd0,1)              0x05  Extended
  /dev/hde9      /dev/ad4s5      (hd0,4)    /boot   0x83  Linux
  /dev/hde10     /dev/ad4s6      (hd0,5)    swap    0x82  Linux swap
  /dev/hde11     /dev/ad4s7      (hd0,6)    /       0x83 
Linux             
/dev/hde3      /dev/ad4s3      (hd0,2)              0xa5  BSD/386
  /dev/hde12     /dev/ad4s3a     (hd0,2,a)  /  
  /dev/hde13     /dev/ad4s3e     (hd0,2,e)  /var
  /dev/hde14     /dev/ad4s3f     (hd0,2,f)  /usr
/dev/hde4      /dev/ad4s4      (hd0,3)              0xa5  BSD/386
  /dev/hde15     /dev/ad4s4a     (hd0,3,a)  /
  /dev/hde16     /dev/ad4s4b     (hd0,3,b)  swap
  /dev/hde17     /dev/ad4s4e     (hd0,3,e)  /var
  /dev/hde18     /dev/ad4s4f     (hd0,3,f)  /usr

So in terms of LBA addressing I'm pretty sure that this is how
Linux,FreeBSD and Grub are all looking at the layout.


>From my 1st post...
>>         grub> debug
>>         grub> fstest
>>         grub> root (hd0,4)
>> <2, 0, 1024><2, 0, 24><128, 0,204><16, 0, 204> Filesystem type unknown,
>> partition type 0x83

this indicates to me that grub is detecting the linux 0x83 identifier in
(hd0,4) also indicated by the sfdisk output but the crux of the matter
is:

What is the criteria that grub uses to find and determine the ext2 file
system?

Can anyone ascertain the value of this grub debug diagnostic
<2, 0, 1024><2, 0, 24><128, 0,204><16, 0, 204> from the command above?

I am still very concerned by the output of sfdisk

>>      #sfdisk -l -x -uS /dev/hde
>> Disk /dev/hde: 59560 cylinders, 16 heads, 63 sectors/track
>> Units = sectors of 512 bytes, counting from 0
>> 
>>    Device Boot    Start       End  #sectors  Id  System
>> /dev/hde1            63   5631695   5631633  a5  BSD/386
>> /dev/hde2       5631696  11775455   6143760   5  Extended
>>                 start: (c,h,s) expected (1023,15,63) found (1023,255,63)
>> /dev/hde3      11775456  18955439   7179984  a5  BSD/386
>>                 start: (c,h,s) expected (1023,15,63) found (1023,255,63)
>> /dev/hde4   *  18955440  60036479  41081040  a5  BSD/386
>>                 start: (c,h,s) expected (1023,15,63) found (1023,255,63)
I
The diagnostic especially for hde2 worries me. If grub is relying on CHS
info to access that partiion's contents then that could be the root of
my problem. Can anyone comment on that?

Perhaps I could gain some info from this. Could anyone running linux
preferably on a IDE hard drive >10GB post the output of these 3
commands?
where hdX is replaced with the correct syntax for your drive.


#dmesg | grep -e \[sh\]d\[a-h\]
and
#sfdisk -l -x -uS /dev/hdX
and
#dd if=/dev/hdX count=1|hexdump -s 0x1be -e '"%07.7_ax  " 16/1 "%02x "
"\n"'

Any other constructive comments are welcome.

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