/tmp, /var/log, /var/tmp as /dev/md - why?

[René Ladan]

2014-07-01 11:25 GMT+02:00 Anton Shterenlikht <mexas at bris.ac.uk>:

> Why is it a good idea to mount /tmp and some var dirs on memory disks:
>
> root at raspberry-pi:/usr/ports # df -m
> Filesystem     1M-blocks Used Avail Capacity  Mounted on
> /dev/mmcsd0s2a     14694  777 12742     6%    /
> devfs                  0    0     0   100%    /dev
> /dev/mmcsd0s1         16    3    13    20%    /boot/msdos
> /dev/md0              28    4    22    16%    /tmp
> /dev/md1              14    0    12     0%    /var/log
> /dev/md2               4    0     4     0%    /var/tmp
> root at raspberry-pi:/usr/ports #
>
> Is this about speed or power, or maybe space?
>
> Mostly write tear because you're using an SD card, and it improves speed
too.


> Can I not put all these dirs on sd card?
>
> You could, but see above.


> I'm new to arm, so maybe things are different
> to other arches.
>

Regards,
René