Re: document ext3 requirements

Martin K. Petersen
2009-01-05T03:22:19Z

>>>>> "Pavel" == Pavel Machek <pavel@suse.cz> writes:

Pavel> Does this sound like a fair summary?

Pavel> Sector writes are atomic (ATOMIC-SECTORS)
Pavel> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

I'd just like to point out that the all-or-nothing hardware sector
atomity thing is -- to a large extent -- a myth.

It is mostly true on SCSI class devices because various UNIX, RAID array
and database vendors have spent many years leaning very hard on the
drive manufacturers to make it so.

But it's not a hard guarantee, you can't get it in writing, and it's not
in any of the standards. Hybrid drives with flash had potential to
close that particular loophole but those appear to be dead in the water.

--
Martin K. Petersen Oracle Linux Engineering