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Re: Problem identified: WAPL/RAIDframe performance problems

mouse%Rodents-Montreal.ORG@localhost (Mouse) writes:

>>>> things.  What I care about is the largest size "sector" that will (in
>>                                     ^^^^^^^
>>>> the ordinary course of things anyway) be written atomically.
>>> Then those are 512-byte-sector drives [...]
>> No; because I can do 4K atomic writes, I want to know about that.

>And, can't you do that with traditional drives, drives which really do
>have 512-byte sectors?  Do a 4K transfer and you write 8 physical
>sectors with no opportunity for any other operation to see the write
>partially done.  Is that wrong, or am I missing something else?

The drive could partially complete the write, i.e. if one of the
latter sectors has a write error or if the drive is powered down
in the middle of the operation.

Sure, you would know about it. But in case of a crash you can't rely
on data consistency.

                                Michael van Elst
                                "A potential Snark may lurk in every tree."

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