The following article describes a situation when all network configuration and iSCSI shares are configured correctly and VMware ESXi can connect and see all LUNs exported from SynetoOS but datastore is not visible on Datastore menu.

On Devices menu using your ESXi Embedded Host Client, iSCSI share is seen in devices page,

but not on Datastores page, the datastore is not present:

The issue here is that VMware has not properly dismounted the volumes before, so it will not automatically mount them. Check, using ESX CLi that there are volumes not mounted because they are seen as snapshots:

~ # esxcli storage vmfs snapshot list
5252c035-8b5fe987-469f-d89d6716f6d8
   Volume Name: VDisk-Vcenter
   VMFS UUID: 5252c035-8b5fe987-469f-d89d6716f6d8
   Can mount: true
   Reason for un-mountability:
   Can resignature: false
   Reason for non-resignaturability: the volume is being actively used
   Unresolved Extent Count: 1

The only way to mount these is to mount them from CLI:

~ # esxcli storage vmfs snapshot mount -u 5252c035-8b5fe987-469f-d89d6716f6d8

After this, the datastore should be visible.

This article is also valid when:

• a clone of a virtual disk is shared through iSCSI,
• upgrades from 2.x to 3.2.x when iSCSI shares are present. Due to the name change of the IQN on Syneto, LUNs may appear as snapshots on hosts.