Re: IDE DMA errors, massive disk corruption: Why? Fixed Yet? W hy not re-do failed op?

[Greg Stark]

"Mudama, Eric" <eric_mudama@xxxxxxxxxx> writes:

> If the disk has write cache enabled, this isn't necessarilly possible, since
> there's nothing in the IDE specification that guarantees the order of writes
> to the media without a FLUSH CACHE (EXT) command.

So, uhm, is there an interface exporting this command to applications?
Databases like Postgres would love to be able to issue such a command.

As it stands they have to do some awful hacks with fsync and sync. Postgres in
particular at certain points just calls sync and then waits an arbitrary time
hoping that that should be enough to get everything to disk.

Some users have in fact resorted to disabling the cache on their ide drives.
And of course it absolutely demolishes performance. Having it be disabled just
at the few points in time when it actually matters would be a huge improvement.

-- 
greg

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