Removing linux-firmware from the build [Devel Digest, Vol 65, Issue 52]

[Yioryos Asprobounitis]

--- On Mon, 8/1/11, Daniel Drake <dsd at laptop.org> wrote:

> From: Daniel Drake <dsd at laptop.org>
> Subject: Re: Removing linux-firmware from the build [Devel Digest, Vol 65, Issue 52]
> To: "Yioryos Asprobounitis" <mavrothal at yahoo.com>
> Cc: devel at lists.laptop.org
> Date: Monday, August 1, 2011, 10:25 AM
> On 28 July 2011 21:08, Yioryos
> Asprobounitis <mavrothal at yahoo.com>
> wrote:
> > For what is worths, with the increasing size of the
> builds I had posted [1] a crude script I was using to remove
> dri, firmware, extra locales and 256x256 ions (61Mb worth on
> os874) which people used, and I did not hear any complains,
> yet ;).
> >
> > Going back to the issue of size, it would appear that
> in os1 tmpfs size (114MB)  is subtracted from the available
> storage.
> > Thus even if os1 is ~660MB the free space is only
> 270MB, since /dev/ubi0_0 is only 898MB instead on 1024M (for
> mtdblok0) in os874.
> > Is this something specific to ubifs or a configuration
> issue?
> 
> I'd be interested to know how you pulled up those numbers,
> but I doubt
> that they are valid. Calculating the amount of free space
> on NAND is a
> complicated issue, and even more complicated when UBI comes
> into play.
> And UBIFS provides much more conservative free space
> readings than
> jffs2, which often tells you that there is more space
> available than
> there actually is.
> 
> That's not to say there isn't an issue here (there may well
> be), but
> you need to prove this with a test that looks at the
> quantity of data
> that can be stored.

My original report was based on the `df' data.
To test how accurate these might be I did the following:

[olpc at xo-11-ea-51 ~]$ df -B M
Filesystem           1M-blocks      Used Available Use% Mounted on
/dev/ubi0_0               878M      621M      253M  72% /
tmpfs                     114M        1M      114M   1% /dev/shm
/tmp                       50M        1M       50M   1% /tmp
vartmp                     50M        1M       50M   1% /var/tmp
varlog                     20M        1M       20M   1% /var/log
/dev/mtdblock2             24M       12M       13M  47% /bootpart

[olpc at xo-11-ea-51 ~]$ sudo dd if=/dev/urandom of=test_free.img bs=1M count=256
256+0 records in
256+0 records out
268435456 bytes (268 MB) copied, 1077.6 s, 249 kB/s

[olpc at xo-11-ea-51 ~]$ df -B M
Filesystem           1M-blocks      Used Available Use% Mounted on
/dev/ubi0_0               878M      871M        3M 100% /
tmpfs                     114M        1M      114M   1% /dev/shm
/tmp                       50M        1M       50M   1% /tmp
vartmp                     50M        1M       50M   1% /var/tmp
varlog                     20M        1M       20M   1% /var/log
/dev/mtdblock2             24M       12M       13M  47% /bootpart

[olpc at xo-11-ea-51 ~]$ sudo dd if=/dev/urandom of=test_free2.img bs=1M count=6
6+0 records in
6+0 records out
6291456 bytes (6.3 MB) copied, 37.2785 s, 169 kB/s

[olpc at xo-11-ea-51 ~]$ df -B M
Filesystem           1M-blocks      Used Available Use% Mounted on
/dev/ubi0_0               878M      875M        0M 100% /
tmpfs                     114M        1M      114M   1% /dev/shm
/tmp                       50M        1M       50M   1% /tmp
vartmp                     50M        1M       50M   1% /var/tmp
varlog                     20M        1M       20M   1% /var/log
/dev/mtdblock2             24M       12M       13M  47% /bootpart

[olpc at xo-11-ea-51 ~]$ sudo dd if=/dev/urandom of=test_free3.img bs=1M count=6
dd: writing `test_free3.img': No space left on device
5+0 records in
4+0 records out
4571136 bytes (4.6 MB) copied, 36.9996 s, 124 kB/s

So `df' looks pretty good to me.

Looking at the `df' output one can see that /dev/ubi0_0 + /dev/mtdblock2 + tmpfs(!?) = 1016 MB just 8MB short of the NAND capacity.
 

> 
> Daniel
>