[Info-vax] RX2800 sporadic disk I/O slowdowns

[Arne Vajhøj]

On 10/20/2024 5:41 PM, Lawrence D'Oliveiro wrote:
> On Sun, 20 Oct 2024 17:23:08 -0400, Arne Vajhøj wrote:
>> Loss of completed/committed data is the problem.
> 
> The problem is not data loss, it is loss of data integrity. This is why we
> have transactions in databases and filesystems: on a crash or loss of
> power, we want transactions to be either completely lost or completely
> saved, not in some in-between incomplete state.
> 
> There is no caching disk controller that knows how to ensure this.

Let me try again.

DB write to plates & system crash => OK but slow
DB write to OS cache & system crash => potential problem with transaction
DB write to RAID controller with battery backup & system crash => OK and 
fast

Arne