>>>>> "Florian-Ewald" == Florian-Ewald Müller <florian-ewald.mueller@xxxxxxxxxxxxxxxx> writes: Florian-Ewald, > 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) Why do you set max_discard_sectors for your device to 128? To my knowledge dm-cache does not do partial allocation. And consequently any discard less than an aligned 256MB will be a nop anyway. -- Martin K. Petersen Oracle Linux Engineering -- 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
