[Info-vax] Do any disks still lie about writing data to permanent storage ?

[Jan-Erik Söderholm]

Den 2021-07-07 kl. 14:24, skrev Simon Clubley:
> On 2021-07-06, <kemain.nospam at gmail.com> <kemain.nospam at gmail.com> wrote:
>>
>> As Jan-Erik correctly stated, there are no "lies".
>>
>> The facts are that regardless of the physical server/storage device, there
>> are different write strategies that one can choose to implement based on
>> performance and data integrity requirements. This is an age-old design
>> decision that goes back decades.
>>
> 
> Since clearly neither you or Jan-Erik understand the issues being
> discussed, here is some reading for you:
> 
> https://queue.acm.org/detail.cfm?id=2367378
> 
> There's no need to read the last bit about 4K sectors if you don't
> want to as it's not applicable to this discussion.
> 
> In summary, yes, there has indeed been an historical issue with some
> disks lying to the disk device driver about whether the data had made
> it to permanent storage yet.
> 
> This has nothing to do with operating system level deferred write caching.
> This is to do with some drives lying about the guarantee they are supposed
> to give to the device driver controlling them.
> 
> What I don't know is if it's still a problem today.
> 
> Simon.
> 

The disk was not lying. It said "I have the data in my cache".
You just had to understand that it was that it was saying.

It is you that used the concept of "lying" and that is not
applicable to hardware. It is humans that lies, not machines.

I'm not depating the base issue here. You are completely right
about that... :-)

Jan-Erik.