opensuse-factory] Warning / ANNOUNCE : upcoming changes in upstreamsystemd regarding /media, /tmp and /var/run | /var/lock

English Install/Boot/Login
1

Frederic Crozat posted the following today on the Factory Mailing list:

this is a announcement regarding changes which have just landed in
upstream systemd (not yet released nor pushed to Factory)
regarding /media and /tmp:

  • /media will no longer mounted as tmpfs. This is because udisks2 will
    no longer use /media for mounting removables devices
    but /run/media/<user>
  • /var/run and /var/lock are no longer bind-mounted to /run | /run/lock.
    We should replace those directories with symlink to /run | /run/lock
    (probably at initrd time, this is what is done on Fedora)
  • /tmp is mounted as tmpfs, to make the default setups as stateless as
    possible. As stated on
    https://fedoraproject.org/wiki/Features/tmp-on-tmpfs , we might need to
    fix some applications to use /var/tmp instead of /tmp when they need
    persistent storage. Another big issue is educating users.
2

Thanks for this useful info Larry. Doesn’t seem to complicated to me.

3

That’s an interesting evolution.

/run first appeared on 12.1 (it was not on 11.4 - I’m still running 11.4 on my main PC - possibly to change this weekend)

and on 12.1 on my sandbox PC I note there is no /run/media (there is a /run/mount).

Thanks for the warning.

4

On 2012-03-27 19:13, Larry Finger wrote:
> - /tmp is mounted as tmpfs, to make the default setups as stateless as
> possible.

it could be catastrophic, IMHO.

–
Cheers / Saludos,

Carlos E. R.
(from 11.4 x86_64 “Celadon” at Telcontar)

5

I am not expecting any problems. I have been using tmpfs for “/tmp” for the last year. For that matter, I have been using that on solaris (at work) for well over a decade.

The one possible problem, is that linux sized a tmpfs file system based on only memory size. Solaris bases it on memory+swap.

6

Carlos E. R. wrote:

> On 2012-03-27 19:13, Larry Finger wrote:
>> - /tmp is mounted as tmpfs, to make the default setups as stateless as
>> possible.
>
> it could be catastrophic, IMHO.
>

FWIW, my stable (11.4) machine has had /tmp in tmpfs since 10.mumble, with
no ill effects - just zoomfast compiles.

7

The only problem I’ve seen is with k3b defaults to using /tmp for temp ISO when copying dvds, the need 4 or 8 gbytes bds require upwards of 25 or 50 . Other then this there is a nice speed bump if you have enough ram.

8

On 2012-03-28 14:06, dwellen wrote:
>
> GeoBaltz;2451871 Wrote:
>> Carlos E. R. wrote:

>>> it could be catastrophic, IMHO.
>>>
>>
>> FWIW, my stable (11.4) machine has had /tmp in tmpfs since 10.mumble,
>> with no ill effects - just zoomfast compiles.
>
> The only problem I’ve seen is with k3b defaults to using /tmp for temp
> ISO when copying dvds, the need 4 or 8 gbytes bds require upwards of
> 25 or 50 . Other then this there is a nice speed bump if you have
> enough ram.

Exactly, that’s one.
If you use programs that use very large temporary files you will have
problems if you don’t have a large swap - and I prefer to have a large “/”
rather than a large swap.

And I do not want/need /tmp to be erased on /boot. Instead, I may have
problems with old files in there staying after a month since last boot.

It is also a problem for small machines with little ram.

–
Cheers / Saludos,

Carlos E. R.
(from 11.4 x86_64 “Celadon” at Telcontar)

9

There is a heated debate about on mailinglist opensuse-devel:
tmp on tmpfs

Such nearly undecidable issues occur when things got merged together where better there be differentiation, most famous trueth:
“Do it most simple as can be but no further!”

So why not introducing an additional feature instead of merging the unmergable:
TMP and an additional
RAMTMP on /run/user/NAME
with some LSB garantied amount of lets say 500 MegaByte for applications which want this!

If then some adm has to please lots of users in parallel he simply can
ln -s /run/user/NAME /tmp/user/NAME/NotEnoughForAll