Re: Xen DomU zvol disk sizes

[mlelstv%serpens.de@localhost (Michael van Elst)]

sebastian%xenoserver.net@localhost (Sebastian Ponitka) writes:

>Am 2025-12-20 16:18, schrieb mlelstv%serpens.de@localhost:
>> My guess is that wd0 is a 512e disk (4k physical sectors, but emulates
>> 512byte/sector) and that isn't handled consistently. Apparently the
>> vdev code uses the physical sector size and the zvol code uses the
>> logical sector size.
>> 
>> Can you please verify that wd0 is such a disk ?

>I guess this is one of these disks:


That's true for almost every larger disk nowadays.

The vdev code uses the physical sector size to set the ashift value.
That's where ashift=12 comes from.

However, a zvol uses the maximum of the ashift values of all used
vdevs and should also return the physical sector size. It also
computes the sector count from the volume size and the sector size,
so the values must be consistent.