[DRBD-user] [PATCH v5 01/11] block: make generic_make_request handle arbitrarily sized bios

Martin K. Petersen martin.petersen at oracle.com
Tue Aug 11 19:36:39 CEST 2015

Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.


>>>>> "Mike" == Mike Snitzer <snitzer at redhat.com> writes:

Mike> DM-thinp processes discards internally before it passes them down
Mike> (if configured to do so).  If a discard is smaller than the
Mike> granularity of a thinp block (whose size is configurable) or if
Mike> the start and end of the discard's extent is misaligned (relative
Mike> to the thinp blocks mapped to the logical extent) then the discard
Mike> won't actually discard partial thinp blocks.

That's fine. You can throw away anything you don't like as long as
discard_zeroes_data=0.

But I don't understand why having an artificial cap at 2GB fixes
things. Other than making it less likely for you to receive a runt by
virtue of being aligned to a power of two.

-- 
Martin K. Petersen	Oracle Linux Engineering



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