Re: Y2038 - best way forward in Debian?

[Ansgar <ansgar@43-1.org>]

Russ Allbery writes:
> Ansgar <ansgar@43-1.org> writes:
>
>> So maybe just recommend people to move to 64-bit architectures and put
>> 32-bit applications in a time namespace so they believe they are still
>> in 2001 ;-) 32-bit architectures will probably still be useful in
>> embedded contexts for a long time and there it might be easier to just
>> change the ABI, but for a general-purpose distribution we start seeing
>> more and more problems and I don't really see us supporting them as a
>> full architecture in 10+ years.
>
> If we go down this path, can we make cross-grading a supported feature for
> the next stable release?  I'm sure I'm not the only one who is stuck with
> continuously-upgraded i386 hosts who has been wanting to switch but has
> been waiting until cross-grading is a little bit less scary.

I think the window of opportunity to support this is already over: most
people have already migrated to amd64, there is no real incentive for
these to spend effort on adding support for cross-grading (besides
academic interest, but I for example find adding support for one-time
migrations of legacy systems not that rewarding).

So you would need to recruit people still running i386 hosts, but for
each individual it might be easier to just wait for still existing i386
systems to be decommissioned or just reinstall. (I would likely
recommend reinstalling ancient systems for various reasons anyway.)

For just avoiding the Y2038 problem, i386 might sort itself out already
without additional intervention. From recent popcon reports I get:

| Release        |  i386 |  amd64 | i386/amd64 (%) |
|----------------+-------+--------+----------------|
| 1.41 (etch)    |   323 |     66 |           4.89 |
| 1.46 (lenny)   |   958 |    440 |           2.18 |
| 1.49 (squeeze) |  1753 |   2553 |           0.69 |
| 1.56 (wheezy)  |  3573 |   9455 |           0.38 |
| 1.61 (jessie)  |  4687 |  26977 |           0.17 |
| 1.64 (stretch) |  4932 |  62619 |           0.08 |
| 1.67 (buster)  |  3978 |  66169 |           0.06 |
| 1.69 (t/u)     |   360 |  10445 |           0.03 |
|----------------+-------+--------+----------------|
| Overall        | 20728 | 180079 |           0.12 |
#+TBLFM: $4=$2/$3;%.2f

I'll assume the composition of installations within a release didn't
change over time.

This shows exponential decay for i386 installations (which is expected)
with a factor of ~0.5 for each release.  If we consider 10 years in the
future or 5 releases, one would expect i386 usage to have gone down to
about 0.03 of the current value, that is about 0.002 of installations.

Ansgar