parted-1.4.11 seemed to cause Invalid Media Type

[Simon Dalley]

I have had a slight disaster when resizing a couple of FAT32 partitions.

I have a hard disk which _had_ a 779121KB (according to Linux fdisk)
FAT32 partition on hda1 (cylinders 1-97). This was C: under my Windows
95 OSR2.

It also had a D: drive, cyls 98-163, a logical partition of
530113KB which was also FAT32, on hda5.

I also had an E: drive (FAT16) on hda6.

hda7 - hda12 are GNU/Linux ext2 and swap partitions.

The extended partition is hda2 which contains the D: and E: drives
and all logical Linux partitions.

Since I was getting tight on space on C: but had plenty spare on D:, I
thought I would use parted to shrink D: (and hence the start of the
extended partition) so that I could expand primary partition C:.

The sequence of parted commands was something like
    resize 5 840 1278.610
(previous start of 5 was around 780, no change to end)
(This gave 5 occupying 839.333 - 1278.610).
Then adjusted bottom of extended partition to correspond with new bottom
of D: drive:
    resize 2 839.333 6181.259
(previous start of 2 was a smidgeon (=far less than a cylinder) less
that previous start of 5, end was unchanged from previous value)
(This resulted in 2 occupying 831.489 - 6181.259, starting about a full
cylinder less than I expected - clue?)
    resize 1 0.031 831.489
(previous values for 1 were 0.031 to same value as prev. start of 2).

The overall result was as below:
/-------------
centaur:~ # /usr/local/sbin/parted -i /dev/hda
GNU Parted 1.4.11
Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
This program is free software, covered by the GNU General Public
License.

This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the
implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
PURPOSE.  See the GNU General Public License for
more details.

GNU Parted's development is supported by Conectiva, www.conectiva.com

Using /dev/hda
Warning: The operating system thinks the geometry on /dev/hda is
2482/255/63.  Therefore, cylinder 1024 ends at
8032.499M.  You should check that this matches the BIOS geometry before
using this program.
(parted) print
Warning: Unable to align partition properly.  This probably means that
another partitioning tool generated an
incorrect partition table, because it didn't have the correct BIOS
geometry.  It is safe to ignore,but ignoring
may cause (fixable) problems with some boot loaders.
Ignore Cancel ? i
Disk geometry for /dev/hda: 0.000-19470.937 megabytes
Disk label type: msdos
Minor    Start       End     Type      Filesystem  Flags
1          0.031    831.489  primary   FAT
2        831.489   6181.259  extended
5        839.333   1278.610  logical   FAT
6       1278.642   1404.118  logical   FAT
7       1404.150   1670.822  logical   ext2
8       1670.854   1804.174  logical   linux-swap
9       1804.206   2023.813  logical   ext2
10      2023.845   4016.250  logical   ext2
11      4016.281   5098.754  logical   ext2
12      5098.786   6181.259  logical
3       6181.260   6196.948  primary   ext2        boot
4       6196.948  19469.399  primary   ext2
(parted) check 1
(parted) check 2
Error: Could not detect file system.
(parted) check 5
(parted) check 6
(parted)
---------------/

I then rebooted to w95 and observed that both my C: and D: drives
functioned beautifully with their new sizes.

I then repeated the operation on my backup disk and used dd to back up
/dev/hda1 and /dev/hda5 to identical partitions on the new disk.

Imagine my dismay to then discover that my _E:_ drive (/dev/hda6)
could no longer be
read by windows. It gave something like "there has been a device failure
on this disk". Booting from a w95 floppy gave no problems with dir
command on C: and D:, but dir on E: gave
    Invalid media type error
    Abort, Retry, Fail ?

Rebooting under Linux, I was able to mount and access this partition
with no problems at all, thank goodness.

For what it's worth, the output of Linux fdisk is shown below:
/---------------
centaur:~ # fdisk /dev/hda

The number of cylinders for this disk is set to 2482.
There is nothing wrong with that, but this is larger than 1024,
and could in certain setups cause problems with:
1) software that runs at boot time (e.g., LILO)
2) booting and partitioning software from other OSs
   (e.g., DOS FDISK, OS/2 FDISK)

Command (m for help): p

Disk /dev/hda: 255 heads, 63 sectors, 2482 cylinders
Units = cylinders of 16065 * 512 bytes

   Device Boot    Start       End    Blocks   Id  System
/dev/hda1             1       106    851413+   b  Win95 FAT32
/dev/hda2           107       788   5478165    5  Extended
/dev/hda3   *       789       790     16065   83  Linux
/dev/hda4           791      2482  13590990   83  Linux
/dev/hda5           108       163    449820    b  Win95 FAT32
/dev/hda6           164       179    128488+   6  FAT16
/dev/hda7           180       213    273073   83  Linux
/dev/hda8           214       230    136520+  82  Linux swap
/dev/hda9           231       258    224878   83  Linux
/dev/hda10          259       512   2040223   83  Linux
/dev/hda11          513       650   1108453   83  Linux
/dev/hda12          651       788   1108453   83  Linux

Command (m for help): q

-----------/
I then tarred all files off E: (hda6) to a tarfile on hda12.

Rebooting in full windows95, I ran w95 FDISK in a DOS box. This showed
one DOS partition, one extended partition and 2 non-DOS partition in the
primary entries. The extended partition displayed as _empty_ in spite of
windows being able to see D: just fine.

Then tried (in the dos box) doing format e:. Appeared to run fine - gave
nice new empty filesystem.

Rebooted in linux, ran fdisk. Alas, most of the extended partitions were
gone altogether:
/-----
Warning: invalid flag 0x0000 of partition table 6 will be corrected by
w(rite)
Command (m for help): p

Disk /dev/hda: 255 heads, 63 sectors, 2482 cylinders
Units = cylinders of 16065 * 512 bytes

   Device Boot    Start       End    Blocks   Id  System
/dev/hda1             1       106    851413+   b  Win95 FAT32
/dev/hda2           107       788   5478165    5  Extended
/dev/hda3   *       789       790     16065   83  Linux
/dev/hda4           791      2482  13590990   83  Linux
/dev/hda5           108       163    449820    b  Win95 FAT32
------/
Parted gave:
/---------
(parted) print
Error: Invalid partition table on /dev/hda - wrong signature 0
Ignore Cancel ? i
Disk geometry for /dev/hda: 0.000-19470.937 megabytes
Disk label type: msdos
Minor    Start       End     Type      Filesystem  Flags
1          0.031    831.489  primary   FAT
2        831.489   6181.259  extended
5        839.333   1278.610  logical   FAT
3       6181.260   6196.948  primary   ext2        boot
4       6196.948  19469.399  primary   ext2
(parted)
----------/
It is definitely a bug that /dev/hda6 (my E:) became inaccessible
under W95 after adjusting the boundary between C: and D: with parted,
wouldn't you think?

I am useing Suse 6.2 distribution.

If there is any more info that I can provide, please let me know.

Maybe documentation could be improved too? It was not clear about the
order things should be done in where moving extended partitions was
concerned.

Backups are, indeed, a Good Thing. All the best for Parted, the GPL,
and Free Software.

Best regards,
Simon
-- 
Simon Dalley CEng MIEE, address@hidden
tel +44 (0) 1235 816206