[CentOS] Re: ACID-compliant filesystem

chrism at imntv.com chrism at imntv.com
Sat Sep 9 22:08:32 UTC 2006

Les Mikesell wrote:
> On Sat, 2006-09-09 at 12:43, Lamar Owen wrote:
>> On Tuesday 05 September 2006 22:35, R P Herrold wrote:
>>> This bug hinges, very much, on the non-atomic nature of 'hot'
>>> system updates, and the fact that the yum-needed,
>>> sqlite-maintinaed cache of pacakges got munged half way
>>> through, to reproduce.
>> Sounds like a database type issue; that is, it could be demonstrated that a 
>> multiversion concurrency control (MVCC) mechanism, similar to the PostgreSQL 
>> backend, for the whole filesystem, would help this sort of thing.  That is, a 
>> filesystem on ACID.  (Atomicity, Consistency, Isolation, Durability: the 
>> magic mantra of database management).
>> A real transactional filesystem would allow truly atomic system updates.  But, 
>> of course, there are definite downsides to that.
> I think you are missing the big picture here.  Yum is managing the
> whole system.  Given an ACID database, would you expect to be
> able to upgrade it to a new, potentially incompatible version of
> an ACID database with transactions in progress?  What yum needs
> is just some special consideration when modifying its own
> components.

A simple solution...install 3-phase power at your home, dedicate an air 
conditioned room to the project, buy a VAX and run VMS.  :-)

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