Partitioning And Formatting A Large Disk (2086.09GB)
Hello fellow Debian aficionados,
I'm having a hard time trying to figure out how to partition and format
a large disk.
I have a 3ware card and an array defined thusly:
# tw_cli /c4/u0 show
Unit UnitType Status %Cmpl Port Stripe Size(GB) Blocks
u0 RAID-5 OK - - 64K 2086.09
When I went to try to partition the disk with fdisk, it said:
# fdisk /dev/sdb
Device contains neither a valid DOS partition table, nor Sun, SGI or
Building a new DOS disklabel. Changes will remain in memory only,
until you decide to write them. After that, of course, the previous
content won't be recoverable.
You must set cylinders.
You can do this from the extra functions menu.
Warning: invalid flag 0x0000 of partition table 4 will be corrected by
I've never had to calculate geometry before, so I gave it a try.
First thing I did was (n00b alert) count the bytes on /dev/sdb. (Does
tw_cli consider 1GB = 1000MB or 1024MB? What about fdisk? If I count
it myself then I won't have to care.) Turns out /dev/sdb is
2239920865280 bytes. So, if I use the default: heads=255,
sectors/track=63, sector size=512, then the number of cylinders should
be 272321 -- well within the 1-1048576 range. (That comes out to be a
total of 2239916474880 bytes.)
Command (m for help): x
Expert command (m for help): ?
b move beginning of data in a partition
c change number of cylinders
d print the raw data in the partition table
e list extended partitions
f fix partition order
g create an IRIX (SGI) partition table
h change number of heads
m print this menu
p print the partition table
q quit without saving changes
r return to main menu
s change number of sectors/track
v verify the partition table
w write table to disk and exit
Expert command (m for help): s
Number of sectors (1-63, default 63):
Using default value 63
Warning: setting sector offset for DOS compatiblity
Expert command (m for help): h
Number of heads (1-256, default 255):
Using default value 255
Expert command (m for help): c
Number of cylinders (1-1048576): 272321
The number of cylinders for this disk is set to 272321.
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., old versions of LILO)
2) booting and partitioning software from other OSs
(e.g., DOS FDISK, OS/2 FDISK)
Expert command (m for help): r
Command (m for help): n
p primary partition (1-4)
Partition number (1-4): 1
First cylinder (1-4972, default 1):
I thought I just set the number of cylinders to 272321. Where is 4972
Using default value 1
Last cylinder or +size or +sizeM or +sizeK (1-4972, default 4972):
Using default value 4972
Is there anyone more experienced than I that can clue me in?