[Info-vax] RMS journaling - how it works (for dummies)

[plugh]

On Sunday, July 16, 2023 at 9:08:06 AM UTC-7, d45 n0x8!7 wrote:
> On Sunday, July 16, 2023 at 5:52:59 PM UTC+3, Hein RMS van den Heuvel wrote: 
> > Did you just want an explanation (how deep?) or do you have a business requirement for which you think RMS-Journaling might offer a solution? What is the exact problem you are trying to solve (if any).
> As deep as possible. 
> I'm need to implement (in pure C of course, not in BLISS :-) ) a logic for atomic write for 4k block on several physical devices (with 512 bytes granularity) in Soft. Def. Stor. project. 
> In a couple words: I/O request for 4k block should be spread over 4-8 disks as "atomic" action. 
> There is "start TX" phase - and "end TX" phase. My driver accept an I/O request for the particular block and wait for "end TX" signal. 

I forgot to add -
This looks like a roll-your-own 2-phase commit that's missing "commit  / rollback" logic. What you're describing is an in-line protocol that's also missing a time-out, i.e. what happens when "end TX" never arrives?

anyway...
> 
> 
> > Hope this helps, 
> > Hein. 
> Thanks a lot for answer. 
> 
> 
> PS: Sorry, but this project is for Snack Oil OS but not for OpenVMS.