Partitioning in Linux
Some time ago I needed to make partition of my thumb
drive in Linux environment; I found lot of material on different web-pages and
blogs. It was really all helpful to me and I successfully learnt the way to
partition my drive (Thanks to my friend Bahar Ali)
I’m sharing my experience on my blog so that it can
help other people as well.
(If I’m wrong somewhere or you feel my bad English –
Please apologize me)
Details
Text marked within [] shows user input.
Determine, where the device is on your system
Plug the thumb drive into USB port. After doing that,
do the following to determine which device it is on your system.
$ [dmesg | tail]
...
[ 6854.215650] sd 7:0:0:0:
[sdc] Mode Sense: 0b 00 00 08
[ 6854.215653] sd 7:0:0:0:
[sdc] Assuming drive cache: write through
[ 6854.215659] sdc: sdc1
[ 6854.218079] sd 7:0:0:0:
[sdc] Attached SCSI removable disk
[ 6854.218135] sd 7:0:0:0:
Attached scsi generic sg2 type 0
...
In this case, it shows up as /dev/sdc (note sdc inside
the square brackets above).
Check to see if the drive has automatically been mounted
Note there may be more than one partition (only one
shown in the example below).
$ [df -h]
Filesystem Size Used Avail Use% Mounted on
...
/dev/sdc1 400M 94M
307M 24% /media/disk
...
If mounted, un-mount it
$ [umount /media/disk]
Start fdisk
Be sure to choose the whole device (/dev/sdc), not a
single partition (/dev/sdc1).
$ [sudo fdisk /dev/sdc]
Print the partition record
Make sure to write down the number of bytes on the
drive (in this example, 2021654528).
Command (m for help) : [p]
Disk /dev/sdc: 2021 MB,
2021654528 bytes
255 heads, 63 sectors/track,
245 cylinders
Units = cylinders of 16065 *
512 = 8225280 bytes
Device Boot Start End Blocks
Id System
/dev/sdc1 *
1 246 1974240+
c W95 FAT32
(LBA)
Partition 1 has different
physical/logical endings: phys=(244, 254, 63) logical=(245, 200, 19)
Delete any partitions that are there already
Command (m for help): [d]
Selected partition 1
Set the Geometry of the Thumb Drive
If the print out above does not show 255 heads, 63
sectors/track, then do the following expert mode steps to redo the SD
Card:
§
Go into expert
mode.
Command (m for help): [x]
§
Set the number of
heads to 255.
Expert Command (m for help):
[h]
Number of heads (1-256, default
xxx): [255]
§
Set the number of
sectors to 63.
Expert Command (m for help):
[s]
Number of sectors (1-63,
default xxx): [63]
§
Now Calculate the
number of Cylinders for your SD Card.
#cylinders = FLOOR (the number
of Bytes on the SD Card (from above) /
255 / 63 / 512)
So for this example: 2021654528 / 255 / 63 / 512 = 245.79. So we use 245 (i.e. truncate, don't round).
§
Set the number of
cylinders to the number calculated.
Expert Command (m for help):
[c]
Number of cylinders (1-256,
default xxx): [enter the number you calculated]
§
Return to Normal
mode.
Expert Command (m for help):
[r]
Print the partition record to check your work
Command (m for help): [p]
Disk /dev/sdc: 2021 MB,
2021654528 bytes
255 heads, 63 sectors/track,
245 cylinders
Units = cylinders of 16065 *
512 = 8225280 bytes
Device Boot Start End Blocks
Id System
Create the Linux partition
Command (m for help): [n]
Command action
e
extended
p
primary partition (1-4)
[p]
Partition number (1-4): [2]
First cylinder (52-245, default
52): [(press Enter)]
Using default value 52
Last cylinder or +size or
+sizeM or +sizeK (52-245, default 245):
[(Press Enter)]
Using default value 245
Print to Check Your Work
Command (m for help): [p]
Disk /dev/sdc: 2021 MB,
2021654528 bytes
255 heads, 63 sectors/track,
245 cylinders
Units = cylinders of 16065 *
512 = 8225280 bytes
Device Boot Start End Blocks
Id System
/dev/sdc1 52 245
1558305 83 Linux
Save the new partition records onto the Drive
This is an important step. All the work up to now has
been temporary.
Command (m for help): [w]
The partition table has been
altered!
Calling ioctl() to re-read
partition table.
WARNING: Re-reading the
partition table failed with error 16: Device
or resource busy.
The kernel still uses the old
table.
The new table will be used at
the next reboot.
WARNING: If you have created or
modified any DOS 6.x partitions, please see the fdisk manual page for
additional information.
Syncing disks..
Format the partitions:
The volume name is LABEL1 by these commands. You can
substitute your own volume labels.
$ [sudo mkfs.ext3 -L LABEL1
/dev/sdc2]
mke2fs 1.40-WIP (14-Nov-2006)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
195072 inodes, 389576 blocks
19478 blocks (5.00%) reserved
for the super user
First data block=0
Maximum filesystem
blocks=402653184
12 block groups
32768 blocks per group, 32768
fragments per group
16256 inodes per group
Superblock backups stored on
blocks:
32768, 98304, 163840, 229376, 294912
Writing inode tables: done
Creating journal (8192 blocks):
done
Writing superblocks and
filesystem accounting information:
Press Enter to finish…
Now you are done with a Linux Partition – Congrats
No comments:
Post a Comment