Q:

Archlinux on raspberry pi shows less memory on SD

Hello I have a raspberry PI with a 8GB SD card in it where I have installed Archlinux on. 
Now i was curious how much space I have used until now after installing all the packages I needed for a private dev server. this is the result.

Filesystem      Size  Used Avail Use% Mounted on
/dev/root       1.7G  899M  690M  57% /
devtmpfs         83M     0   83M   0% /dev
tmpfs           231M     0  231M   0% /dev/shm
tmpfs           231M  256K  231M   1% /run
tmpfs           231M     0  231M   0% /sys/fs/cgroup
tmpfs           231M  176K  231M   1% /tmp
/dev/mmcblk0p1   90M  9.0M   81M  10% /boot

As u see it shows me only 1.7G instead of +- 8G I think this is because I have installed it once on the SD card but after i messed up something I tried it again.. could it be possible that the old installation is still on the SD card? how can I see this and delete this if this is the case? or is this normal?
Thanks in advance

A:

Beware: arch has moved to a slightly different partitioning scheme which will cause the above to fail.
See this blog post for details, but the short version is there are now three partitions. p02 is an Extended partition containing the p05 logical partition.
so:
d 2
n e 2 <cr><cr>
n l <cr><cr>
w

then reboot and resize (p05 instead of p02)
resize2fs /dev/mmcblk0p5

A:

This is how I solved this
As root:
fdisk /dev/mmcblk0
Delete the second partition /dev/mmcblk0p2
d
2
Create a new primary partition and use default sizes prompted. This will then create a partiton that fills the disk
n
p
2
enter
enter
Save and exit fdisk:
w
Now reboot. Once rebooted: 
resize2fs /dev/mmcblk0p2
Your main / partition should be the full size of the disk now.

