Fun with old machines and big disks

[Patrick Ale]

Hi,

I put a Sil 3512 PCI SATA card in my Ultra 5 and added a 1TB SATA disk.
To state the obvious to the question "why would you do that" the
answer is "because I can" ;-)

When partitioning the harddrive with a DOS label, I can partition the full 1TB.

DOS DISK LABEL output:
---------------------------------------
Disk /dev/sdb: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x16b15aba

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1               1      121601   976760001   83  Linux


mkfs.ext3 with DOS LABEL output
----------------------------------------------------------
mke2fs 1.41.9 (22-Aug-2009)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
61054976 inodes, 244190000 blocks
12209500 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=0
7453 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
        32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
        4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968,
        102400000, 214990848

Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done

This filesystem will be automatically checked every 27 mounts or
180 days, whichever comes first.  Use tune2fs -c or -i to override.


df -h output with DOS LABEL
----------------------------------------------
[root@medusa patrick]# mount /dev/sdb1 /mnt
[root@medusa patrick]# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/sdc1              40G  2.4G   35G   7% /
/dev/sda1            1012M   54M  907M   6% /boot
/dev/sdc5              20G  172M   19G   1% /home
/dev/sdc4             9.9G  242M  9.2G   3% /var
tmpfs                 248M     0  248M   0% /dev/shm
/dev/sdb1             917G  200M  871G   1% /mnt



Great so far, now for the issue in two steps.


fdisk /dev/sdb again, 's' for creating a new Sun Label.

fdisk output with SUN LABEL
----------------------------------------------
Disk /dev/sdb (Sun disk label): 255 heads, 63 sectors, 56065 cylinders
Units = cylinders of 16065 * 512 bytes

   Device Flag    Start       End    Blocks   Id  System
/dev/sdb1             0    121595 976711837+  83  Linux native
/dev/sdb2  u     121595    121601     48195   82  Linux swap
/dev/sdb3             0    121601 976760032+   5  Whole disk


mkfs.ext3 output with SUN LABEL
------------------------------------------------------------
mke2fs 1.41.9 (22-Aug-2009)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
61046784 inodes, 244177958 blocks
12208897 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=0
7452 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
        32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
        4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968,
        102400000, 214990848

Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done

This filesystem will be automatically checked every 32 mounts or
180 days, whichever comes first.  Use tune2fs -c or -i to override.


df -h output with SUN LABEL
-----------------------------------------------
[root@medusa patrick]# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/sdc1              40G  2.4G   35G   7% /
/dev/sda1            1012M   54M  907M   6% /boot
/dev/sdc5              20G  172M   19G   1% /home
/dev/sdc4             9.9G  242M  9.2G   3% /var
tmpfs                 248M     0  248M   0% /dev/shm
/dev/sdb1             917G  200M  871G   1% /mnt


This was step 1, to prove that both DOS label and Solaris label are
capable to address the full 1TB, but now..

[root@medusa patrick]# fdisk /dev/sdb

Command (m for help): p

Disk /dev/sdb (Sun disk label): 255 heads, 63 sectors, 56065 cylinders
Units = cylinders of 16065 * 512 bytes

   Device Flag    Start       End    Blocks   Id  System
/dev/sdb1             0    121595 976711837+  83  Linux native
/dev/sdb2  u     121595    121601     48195   82  Linux swap
/dev/sdb3             0    121601 976760032+   5  Whole disk


Command (m for help): d
Partition number (1-8): 2

Command (m for help): d
Partition number (1-8): 1

Disk /dev/sdb (Sun disk label): 255 heads, 63 sectors, 56065 cylinders
Units = cylinders of 16065 * 512 bytes

   Device Flag    Start       End    Blocks   Id  System
/dev/sdb3             0    121601 976760032+   5  Whole disk

Command (m for help): n
Partition number (1-8): 1
First cylinder (0-56065): 0
Last cylinder or +size or +sizeM or +sizeK (0-56065, default 56065): 56065

Command (m for help): p

Disk /dev/sdb (Sun disk label): 255 heads, 63 sectors, 56065 cylinders
Units = cylinders of 16065 * 512 bytes

   Device Flag    Start       End    Blocks   Id  System
/dev/sdb1             0     56065 450342112+  83  Linux native
/dev/sdb3             0    121601 976760032+   5  Whole disk




Command (m for help): n
Partition number (1-8): 2
Other partitions already cover the whole disk.
Delete some/shrink them before retry.


And here is where it goes wrong. Suddenly fdisk can only partition
half of the disk, 500GB. It doesn't make sense to me as two other
methods do address the full 1TB.

mkfs + mount to confirm the above:

mke2fs 1.41.9 (22-Aug-2009)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
28147712 inodes, 112585528 blocks
5629276 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=0
3436 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
        32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
        4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968,
        102400000

Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done

This filesystem will be automatically checked every 27 mounts or
180 days, whichever comes first.  Use tune2fs -c or -i to override.


[root@medusa patrick]# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/sdc1              40G  2.4G   35G   7% /
/dev/sda1            1012M   54M  907M   6% /boot
/dev/sdc5              20G  172M   19G   1% /home
/dev/sdc4             9.9G  242M  9.2G   3% /var
tmpfs                 248M     0  248M   0% /dev/shm
/dev/sdb1             423G  199M  402G   1% /mnt



Patrick