In general, the iSCSI service operates on individual vFiler units, treating each of the vFiler units like a physical storage system. But the iSCSI software adapter (iSCSI software target) and the commands that manage and report on it, and the underlying NICs, operate on the hosting storage system.
Because an iSCSI adapter on a storage system has only one identity (there are no vFiler unit-specific adapter names), there is only one set of iSCSI sessions and statistics.
For more information about the iSCSI service, see the Data ONTAP SAN Administration Guide for 7-Mode.
You must keep in mind the following considerations about the iSCSI service on the hosting storage system:
- The iswt command, which you use to manage the iSCSI service on the storage system’s NICs, operates on the hosting storage system, not on individual vFiler units.
- The iSCSI software target driver allows the storage system to be accessed as an iSCSI target device over the storage system’s standard network interfaces.
- If iSCSI is licensed on the hosting storage system, the iSCSI service is available by default during the vFiler unit setup.
- The iscsi stats command displays statistics by hosting storage system and iSCSI adapter.
You must keep in mind the following considerations about the iSCSI service on individual vFiler unit:
- The iSCSI protocol can be allowed or disallowed, and the iSCSI service can be started or stopped, for each vFiler unit.
- The iSCSI software adapter is online or offline for each vFiler unit, depending on whether the iSCSI service is running or stopped on that vFiler unit.
- Each vFiler unit has its own iSCSI node name, which includes the vFiler unit’s UUID.
- Portal groups are defined for each vFiler unit.
- iSCSI subcommands operate specifically on each vFiler unit on which they are executed, except for the iscsi stats command.
- You should configure iSCSI security separately for each vFiler unit.
This includes setting the default authentication mode: none, deny, or CHAP. For more information about CHAP, see the Data ONTAP SAN Administration Guide for 7-Mode.
- In the case of CHAP, there is a separate list of initiators and passwords for each vFiler unit.
- You can configure iSNS separately for each vFiler unit.
You can use iscsi isns
subcommands on each vFiler unit
to do the following:
- Configuring which iSNS server to use
- Turning on or turn off iSNS registration
When created, a vFiler unit’s iSNS configuration is in the "not configured" state, regardless of its state on the hosting storage system.
For more information, see the na_iscsi(1) man page.