On Thu, 2019-01-10 at 16:08 +0100, Zdenek Kabelac wrote: > Dne 10. 01. 19 v 14:41 Martin Wilck napsal(a): > > > > I for one would find it very attractive if dm-thin had a mode > > supporting fast zeroout. > > I believe '/sys/block/*/queue/discard_zeroes_data is now always > returning > false for any device as it's been considered as unreliable logic. > > So using 'discard' for zeroing is not really an option here. True. But we have "write_zeroes_max_bytes" instead. In device mapper terms, it's "num_write_zeroes_bios", which isn't set for dm-thin. With the logic outlined above, it could be set, AFAICT. Thanks, Martin -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
