Re: [Drbd-dev] [PATCH 05/30] drbd: Introduce new disk config option rs-discard-granularity

From: Bart Van Assche
Date: Mon Apr 25 2016 - 11:35:36 EST


On 04/25/2016 05:10 AM, Philipp Reisner wrote:
As long as the value is 0 the feature is disabled. With setting
it to a positive value, DRBD limits and aligns its resync requests
to the rs-discard-granularity setting. If the sync source detects
all zeros in such a block, the resync target discards the range
on disk.

Hello Phil,

Can you explain why rs-discard-granularity is configurable instead of e.g. setting it to the least common multiple of the discard granularities of the underlying block devices at both sides?

Thanks,

Bart.