Hi Martin, My (new developed) distributed block device uses a block size of 64K. So, because of the distribution functionality to different underlying slave (dm-cache) block devices, it has: - max_discard_sectors: 128 (64K) - discard_granularity: 65536 (64K) The discard sizes of the (underlying) dm-cache devices are: - max_discard_sectors: 536870912 (256G) - discard_granularity: 268435456 (256M) Regards, Florian On Wed, Jul 27, 2016 at 3:51 AM, Martin K. Petersen <martin.petersen@xxxxxxxxxx> wrote: >>>>>> "Florian-Ewald" == Florian-Ewald Müller <florian-ewald.mueller@xxxxxxxxxxxxxxxx> writes: > > Florian-Ewald, > > Florian-Ewald> My setup is a new developed distributed block > Florian-Ewald> device on top of dm-cache. The dm-cache values are > Florian-Ewald> bigger than those needed by my (new developed) block > Florian-Ewald> device. > > What are the actual values for granularity and max? For your device and > dm-cache respectively. > > -- > Martin K. Petersen Oracle Linux Engineering -- Florian-Ewald Mueller Architecture Board ProfitBricks GmbH Greifswalder Str. 207 D - 10405 Berlin Tel: +49 30 577 008 331 Fax: +49 30 577 008 598 Email: florian-ewald.mueller@xxxxxxxxxxxxxxxx URL: http://www.profitbricks.de Sitz der Gesellschaft: Berlin. Registergericht: Amtsgericht Charlottenburg, HRB 125506 B. Geschäftsführer: Andreas Gauger, Achim Weiss. Please consider the environment before printing this email. -- To unsubscribe from this list: send the line "unsubscribe linux-block" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
