Rpi b+, mkfs.vfat: unable to open /dev/sdg: Device or resour

It's my first time installing arch Linux.
I was following this guide, i did everything i just added sudo http://archlinuxarm.org/platforms/armv6/raspberry-pi

after fdisk i got this:

$this->bbcode_second_pass_quote('', 'C')ommand (m for help): w
The partition table has been altered.
Calling ioctl() to re-read partition table.
Re-reading the partition table failed.: 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).

[WarheadsSE]

step number one: sudo su

Then continue on as root in su.

[kamm]

You didn't mention where the sd card was mounted when you were trying to install arch, but
-- assuming it was plugged into the laptop, and
-- assuming you ran dmesg and verified that it is /dev/sdg
it looks like you didn't unmount it before trying to repartition it. Did you run
sudo umount [mount point of the sd card]
(i.e., /mnt/[card-name] or /media/[login]/[card-name], or whatever, depending on your laptop linux installation)
before running fdisk?

Also, note that "sudo mkfs.vfat /dev/sdX1" should be "sudo mkfs.vfat /dev/sdg1", assuming the card really is sdg.

[kamhagh]

Wow im such an idiot, i forgot about the partitions

Worked now! i can't wait to try it! will post the results here soon!
EDIT: It worked! *pops champagne!*
and wow this is slow, so slow compared to raspian!