Official images without noatime

[Nikolai Lifanov]

On 03/28/16 11:10, José Pérez wrote:
> Hello Nikolai,
> 
> El 2016-03-26 13:32, Nikolai Lifanov escribió:
>> Since we also default to SU-no-J, power failure can be quite bad
>> during, say, installworld.
> 
> Why? I see no relationship between noatime and higer or lower chances to
> loose files while writing them.
> 

A simple case is during install /usr/bin/cmp is ran to compare two
files, atime for /usr/bin/cmp is updated during a crash, and
/usr/bin/cmp is gone on next boot. I then have to copy it out of
/usr/obj and into place and run installworld again. It's the handful of
utilities actually *used* by installworld that do this and mounting root
with noatime stops this from happening.

>> With / noatime, I had my RPI2 lose files like /usr/bin/cmp, /bin/ls,
>> and /bin/cat during a power loss.
> 
> Bad luck. But, again, what is the relation with having or not noatime?
> 
>> Since it's not even possible to cleanly shut down this platform, I'm
>> for enabling noatime for / on
>> at least for RPI and RPI2 platforms.
> 
> My RPI2 shutdown cleanly with shutdown(8) or reboot(8).
> 

It doesn't stay down if the power cable is still connected.
It boots back up immediately, so the only way to shut mine down is to
pull power on it.

> Based on my experience, the less operations you do with a flash
> memory, the longer it lives. Don't forget that flash is a technology
> meant to store large files (images or video) for a few times over the
> lifespan of a card. Throwing a live filesystem at it is, to say the least,
> daring.
> 
> Enabling journaling on flash storage shall be prohibited by law.
> 

I may have been superstitious about journaling (Ian corrected me
earlier), but disabling atime really helps these binaries stay around.

> Let's read again together mount(8)
>              noatime
>                      Do not update the file access time when reading from a
>                      file. [blablabla]
> 
> So, when you mount / with noatime, you are:
> - speeding up your system
> - extending the life of your flash card.
> 
> Same chances to loose files.
> 
> Regards,
> 
> ---
> José Pérez