Postgresql 9.5 on 7.0_STABLE vs 7.1_STABLE

[Dima Veselov <kab00m%lich.phys.spbu.ru@localhost>]

Greetings,

I have recent problem that I can't explain. I had 7.0_STABLE
(GENERIC) box, which was recently upgraded to 7.1_STABLE.

It seems that PostgreSQL 9.5 may not continue working anymore,
saying
FATAL:  could not open shared memory segment "/PostgreSQL.1804289383": Not supported
I booted old kernel back and it work as it should.

I can't explain that, besides:
1. I definitely have lot of 7.1_STABLE boxes with PostgreSQL 
9.5 or 10 working well.
2. PostgreSQL have no special tweaks about memory, so this
is not related to shm parameters.

-- 
Sincerely yours,
Dima Veselov
Physics R&D Establishment of Saint-Petersburg University