Re: RX2800 sporadic disk I/O slowdowns

On 10/21/2024 8:35 AM, Simon Clubley wrote:

On 2024-10-19, Lawrence D'Oliveiro <ldo@nz.invalid> wrote:

On Sat, 19 Oct 2024 21:52:16 -0400, Arne Vajhøj wrote:

The context is one where data loss is not acceptable.

>
Data loss is unavoidable. If the power goes out, all computations in
progress get lost. There?s no way around that.

 Bollocks. It's called checkpointing and restart points for compute
based operations. It's called transaction recovery for I/O based
operations.

I read his comments as being about what happens between
checkpoints/commits.
It is not possible to recover that. But it is not
desirable to recover that, because that would be
an inconsistent state.
begin
update accounts set amount = amount - ? where id = ?
 >>>> here <<<<
update accounts set amount = amount + ? where id = ?
commit
or:
checkpoint m
m.accounts[id_a] -= xframt
 >>>> here <<<<
m.accounts[id_b] += xframt
checkpoint m
is really the same.
Arne