I'm new to storage and vSphere, but I've been doing quite a bit of reading and I have been working my way through vSphere pretty well.
However, I'm kind of confused about something in the vsphere-esxi-vcenter-server-51-storage-guide.pdf.
It says
Networked storage devices are shared. Datastores on networked storage devices can be accessed by multiple
hosts concurrently.
I'm not sure I understand this. As I understand SAN storage, if one of my ESXi hosts is connected to a SAN device ( LUN?), it's the same as a disk being attached to the host phycially, i.e. the host has block level io control over that device/disk. How can that be shared then? Wouldn't it cause data corruption to have two hosts with block level access to a given device?