On Monday, June 17, 2019 10:19 AM, Ondrej Kozina <okozina@xxxxxxxxxx> wrote: > On 6/15/19 2:49 PM, Jordan Glover wrote: > > > One question: does reencryption allows changing block size? > > For example: old size:512, new size:4096 > > Hi, > > new reencryption code indeed supports change of encryption block size > (both ways), even in online mode. But user has to ask for it explicitly > by specifying --sector-size parameter when initializing device > reencryption. By default we retain original encryption sector size (from > luksFormat action). > > But I strongly recommend to be careful with it. Changing encryption > sector size on devices underneath existing filesystem is tricky. See my > post on pvmove of existing fs from dm-crypt with 512 sector size to > dm-crypt with 4K sector size: > https://www.saout.de/pipermail/dm-crypt/2019-February/006078.html > > You have to ensure the filesystem can handle device limits increase to > 4K (that's what encryption sector size increase actually does). It's > safe for fs formatted with blocksize set to 4K. But if fs was formatted > with blocksize < 4K do not try do not try to increase encryption sector > size beyond filesystem block size. > > Kind regards > O. Great, thx for the answer. Jordan _______________________________________________ dm-crypt mailing list dm-crypt@xxxxxxxx https://www.saout.de/mailman/listinfo/dm-crypt
