maria-discuss team mailing list archive

[Reindl Harald <h.reindl@xxxxxxxxxxxxx>]

Am 08.12.22 um 18:59 schrieb Gordan Bobic:
> On Thu, Dec 8, 2022 at 7:28 PM Reindl Harald <h.reindl@xxxxxxxxxxxxx> wrote:
> > MariaDB does the same as the filesystem
> > InnoDB in fact is more ore less a FS on top of a FS
>
> So why do it at both levels? 

because the FS layer can't detect MariaDB errors?

> And what makes doing it at MariaDB level
> in any way better than doing it somewhere else?

which magic should do it somewehre else?

> > "Some of us run MariaDB on file systems that do their own block
> > checksumming, and thus run innodb_checksum_algorithm=none" makes you
> > looking like a fool - period
> >
> > are you dumb or why don't you understand that the filesystem is a
> > completly different layer and has no clue about the data itself?
>
> Are you too dumb to understand that if a block is corrupted at InnoDB
> level MariaDB can't do anyting to fix it, but if a block is corrupted
> at lower level, ZFS can fix it from redundantly stored data and
> MariaDB never gets to ingest a corrupted block in the first place?

it can at least fail early instead work with corrupted data

> If you disagree, please describe a scenario in which an InnoDB page
> checksum does anything useful if the file system it is on has built in
> block checksumming and data redundancy.
INNDOB CHECKSUMS DETECT DATA CORRUPTION WITHIN MARIADB NOT CAUSED BY ANY 
FILESYSTEM ISSUE AT ALL

the filesystem can't do that with it's block checksumming and data 
redundancy because there is *nothing wrong* for the view of the FS layer

one is for consistency of the database
one is for consistency of the underlying filesystem

two worlds and i simply don't get why people not understanding such 
basics  work in the IT but to top that talking nonsense on mailing-lists

AGAIN: THE FILESYSTEM CAN'T DO ANYTHING BECAUSE IT'S NOT AFFECTED