Hi, We have a ubuntu 20.04 LTS VM and it could read the sector on an attached virtual disk.
So we have an ESXi 7.0 update 2 VMware host, and we created a thin-provisioned vmdk file in the host, using the following command and the creation was successful:
vmkfstools -c 1536G -a lsilogic -d thin secttest_huge_1.vmdk
Option --adaptertype is deprecated and hence will be ignored
Create: 100% done.
We then created an ubuntu 20.04 LTS virtual machine on the host, with the above virtual disk attached in IndependentNonPersistent mode.
Our test is to read three different disk sectors on the ubuntu: first sector, last sector and a sector in the middle. The reading on the first and last sectors are successful and returned buffer are as expected. However the reading of the middle-position sector can succeed but the buffer returned are all bytes of 0s, while we know the buffer should be a meaningful string.
From what we observed so far, this issues only happens with a combination of ESXi 7.0 update 2 and ubuntu 20.04. With a different vmware version or ubuntu version, this issue won't happen.
Any suggestions or ideas would be much appreciated!