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Simon the Pi Man
To Infinity (probably) and beyond
(A beginners Resource for the Raspberry Pi computer using the Debian distro)
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If you are looking for info on the Raspberry Pi computer
stay on this site
however
If you are looking for a good cafe in
Rye in
East Sussex try
"Simon the Pie man" near the church.
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How2 give my Pi more disk space
One of a set of simple easy to use guides for beginners to set up a Raspberry Pi computer.
Ok this instruction sheet will allow you to increase the primary partition of a
Raspberry Pi computer from the default download image of 2Gb. The default image will
only allow the addition of a small number of programs or utilities to the Pi. However
if your image is loaded onto a 4Gb/8Gb or 16Gb card you will be wasting a lot of space.
WARNING: This can permanently damage your booting Raspberry Pi so please be careful,
it wont physically harm the SD Card or your Pi but you may need to reload the Operating
System and rebuild your Pi.
But if you do mess it up dont PANIC see (How2Setup 1. The Pi SD Card).
1. Lets just have a look at the current disk partition.
pi@raspberrypi~$ df -k
-----------------------------------------------------
Filesystem 1K-blocks Used Available Use% Mounted on
tmpfs 95416 0 95416 0% /lib/init/rw
udev 10240 136 10104 2% /dev
tmpfs 95416 0 95416 0% /dev/shm
rootfs 1602528 1206320 314800 80% /
/dev/mmcblk0p1 76186 28089 48097 37% /boot
-----------------------------------------------------
The rootfs filesystem is 80% full to start with so leaves only a small amount of
space spare for programs and utilities.
2. OK lets get going - we first have to run the fdisk utility - please note
there is no real equivalent in the windows world, so be a bit careful to follow the
instructions, the fdisk command allows you to change partition details.
pi@raspberrypi~$ sudo fdisk -cu /dev/mmcblk0
3. Inside this program the main prompt is Command (m for help) and the first
thing we need to find out what are we working with so we type p(rint) to
see what partitions the disk has.
p
-----------------------------------------------------
Disk /dev/mmcblk0: 3965 MB, 3965190144 bytes
4 heads, 32 sectors/track, 60504 cylinders, total sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000ee283
Device Boot Start End Blocks Id System
/dev/mmcblk0p1 2048 155647 76800 c W95 FAT32 (LBA)
/dev/mmcblk0p2 157696 3414015 1628160 83 Linux
/dev/mmcblk0p3 3416064 195584 82 Linux swap / Solaris
-----------------------------------------------------
From the above details we can see that the disk contains 3965Mb which is sectors
(the first blue field), but the maximum sectors that are allocated can be seen
on the third partition with the second highlighted field . So we actually have
3937281 sectors spare and as each sector is 512bytes we have 3937281 * 512 bytes unallocated
to any partitions so in effect spare space this works out about 1.97Mb.
NOTE: Please make a note of the field highlighted in red as this is important
and will be used further on in our guide.
Some notes on the partitions shown above /dev/mmcblk0p1 is the first partition
which contains the debian boot code.
The second partition /dev/mmcblk0p2 is where
the main programs and root of the system are stored - we need to make this bigger.
The
last partition /dev/mmcblk0p3 is the swap partition, and it is where unix puts
programs whan they are not in use, or when the physical memory is fully used - this
always used to be set to aprox 2.5 times physical memory so we will allocate about 2.5 * 256Mb
for swap(as the Pi Model B has 256Mb memory).
As you can see from the highlighted entries above partitions are usually
numbered p1 -> p(x) where x is the last partition.
4. Right we need to delete the swap partition as it stops us expanding the
main partition, and also the second parition with the operating system on, as we will
need to re-create it in a larger size. So lets delete partition 3.
d
3
5. We have deleted the third partition and now to delete the second
partition
d
2
6. Lets just check that the partitions are gone so type p(rint)
again so we can see the current status
p
-----------------------------------------------------
Disk /dev/mmcblk0: 3965 MB, 3965190144 bytes
4 heads, 32 sectors/track, 60504 cylinders, total sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000ee283
Device Boot Start End Blocks Id System
/dev/mmcblk0p1 2048 155647 76800 c W95 FAT32 (LBA)
-----------------------------------------------------
We can see from the above that there is just one partition left, the boot partition.
7. Now we need to re-create the second partition to a larger size
so we use n(ew) p(artition)
n
-----------------------------------------------------
Command action
e extended
p primary partition (1-4)
-----------------------------------------------------
8. Now we need to choose the partition type which should be
a p(rimary) partition.
-----------------------------------------------------
Partition number (1-4):
-----------------------------------------------------
9. And now we need to choose the partition number, so lets re-create
partition 2 in a larger size - to start we need to choose the partition number.
2
-----------------------------------------------------
First sector (155648-7744511, default 155648):
-----------------------------------------------------
10. Next we need to choose the start of the partition.
157696
This MUST BE the figure in red from step 2
-----------------------------------------------------
Last sector, +sectors or +size{K,M,G} (157696-7744511, default 7744511):
-----------------------------------------------------
11. Next we need to choose the end sector of the partition.
The default is always 1 less than the blue highlighted number from step 5. However if
we use the default we will not allow enough space for a 3rd partition - swap.
So we need to allow for about 750Mb of swap space which is about 1500000 sectors.
Therefore lets set the end of the second partition to 7744511 - 1500000 = 6244511 so
lets use that.
6244511
-----------------------------------------------------
Command (m for help):
-----------------------------------------------------
12. Lets just check all is OK at the moment.
p
-----------------------------------------------------
Disk /dev/mmcblk0: 3965 MB, 3965190144 bytes
4 heads, 32 sectors/track, 60504 cylinders, total sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000ee283
Device Boot Start End Blocks Id System
/dev/mmcblk0p1 2048 155647 76800 c W95 FAT32 (LBA)
/dev/mmcblk0p2 157696 6244511 3043408 83 Linux
-----------------------------------------------------
As you can see we now have more blocks than is step 2 for the /dev/mmcblk0p2 partition.
13. Now we need to re-create the swap partition
n
-----------------------------------------------------
Command action
e extended
p primary partition (1-4)
-----------------------------------------------------
14. Now we need to choose the partition type which should be
a p(rimary) partition.
-----------------------------------------------------
Partition number (1-4):
-----------------------------------------------------
15. And now we need to choose the partition number, so lets re-create
the swap partition - to start we need to choose the partition number.
3
-----------------------------------------------------
First sector (155648-7744511, default 155648):
-----------------------------------------------------
16. Next we need to choose the start sector of the partition.
This MUST BE one more than the Last Sector number input in step 9
6244512
-----------------------------------------------------
Last sector, +sectors or +size{K,M,G} (157696-7744511, default 7744511):
-----------------------------------------------------
17. Now we need to choose the end sector of the partition.
The end of the swap partition should be at the end of the disk so press [Enter]
to select the default.
-----------------------------------------------------
Command (m for help):
-----------------------------------------------------
18. Lets just check all is OK at the moment.
p
-----------------------------------------------------
Disk /dev/mmcblk0: 3965 MB, 3965190144 bytes
4 heads, 32 sectors/track, 60504 cylinders, total 7744512 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000ee283
Device Boot Start End Blocks Id System
/dev/mmcblk0p1 2048 155647 76800 c W95 FAT32 (LBA)
/dev/mmcblk0p2 157696 6244511 3043408 83 Linux
/dev/mmcblk0p3 6244512 7744511 750000 83 Linux
-----------------------------------------------------
19. If you are not happy with the above details press [Ctrl]-[C]
to stop the program, nothing will have been changed.
20. All seems ok so now lets write this to the disk.
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 or after you run partprobe(8) or kpartx(8)
Syncing disks.
-----------------------------------------------------
21. We need to reboot for the partition to become active.
pi@raspberrypi~$ sudo reboot
22. Wait till the Pi has rebooted then log back in and run the following
command which will show the current size of the disk partitions.
pi@raspberrypi~$ df -k
-----------------------------------------------------
Filesystem 1K-blocks Used Available Use% Mounted on
tmpfs 95416 0 95416 0% /lib/init/rw
udev 10240 136 10104 2% /dev
tmpfs 95416 0 95416 0% /dev/shm
rootfs 1602528 1206320 314800 80% /
/dev/mmcblk0p1 76186 28089 48097 37% /boot
-----------------------------------------------------
23. Now to runthe following command which will resize your partition
to its new size.
pi@raspberrypi~$ sudo resize2fs /dev/mmcblk0p2
-----------------------------------------------------
resize2fs 1.41.12 (17-May-2010)
Filesystem at /dev/mmcblk0p2 is mounted on /; on-line resizing required
old desc_blocks = 1, new_desc_blocks = 1
Performing an on-line resize of /dev/mmcblk0p2 to 760852 (4k) blocks.
The filesystem on /dev/mmcblk0p2 is now 760852 blocks long.
-----------------------------------------------------
24. Lets re-run the following command which will show the new size of
the disk partitions.
pi@raspberrypi~$ df -k
-----------------------------------------------------
Filesystem 1K-blocks Used Available Use% Mounted on
tmpfs 95416 0 95416 0% /lib/init/rw
udev 10240 136 10104 2% /dev
tmpfs 95416 0 95416 0% /dev/shm
rootfs 2996128 1206312 1641452 43% /
/dev/mmcblk0p1 76186 28089 48097 37% /boot
-----------------------------------------------------
If you look at the rootfs filesystem you will see that the Use% has dropped from 80%
to 43% giving you more space for programs or files on the SD Card.
25. Right lets see if the swap partition is in use.
pi@raspberrypi~$ free -lm
-----------------------------------------------------
total used free shared buffers cached
Mem: 186 38 147 0 5 20
Low: 186 38 147
High: 0 0 0
-/+ buffers/cache: 12 174
Swap: 0 0 0
-----------------------------------------------------
26. Ok the system is not using the swap space so we had better enable it.
pi@raspberrypi~$ sudo vi /etc/fstab
-----------------------------------------------------
proc /proc proc defaults 0 0
/dev/mmcblk0p1 /boot vfat defaults 0 0
#/dev/mmcblk0p3 none swap sw 0 0
-----------------------------------------------------
We just need to uncomment the #/dev/mmcblk0p3 by deleting the # so that
the file looks like
-----------------------------------------------------
proc /proc proc defaults 0 0
/dev/mmcblk0p1 /boot vfat defaults 0 0
/dev/mmcblk0p3 none swap sw 0 0
-----------------------------------------------------
Then save the file :wq
27. A couple more steps and we will be done - so we need to turn our swap
partition into a proper swap partition, so to convert the partition.
pi@raspberrypi~$ sudo mkswap /dev/mmcblk0p3
28. OK we need to reboot now.
pi@raspberrypi~$ sudo reboot
29. Log back in when you reboot then check the swap is now working.
pi@raspberrypi~$ sudo free -lm
-----------------------------------------------------
total used free shared buffers cached
Mem: 186 37 148 0 5 20
Low: 186 37 148
High: 0 0 0
-/+ buffers/cache: 12 173
Swap: 732 0 732
-----------------------------------------------------
Looks like all is working now - Bye Bye
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© simonthepiman.com 2012->2024
email: simon@villagenet.co.uk
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Raspberry Pi Foundation is a UK registered charity which exists to promote the
study of computer science and related topics, especially at school level, and to put
the fun back into learning computing.
Please Note:- any mention of the Raspberry Pi computer on these pages refers to the
Raspberry Pi Foundation's product, who also have trademark rights to the term 'Raspberry Pi'.
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