iSCSI and VMware ESX3

In deze post som ik even een paar punten op waar je rekening mee moet houden als je gebruik gaat maken van iSCSI in een VI3 omgeving.

Network

Network Speed and Duplex: 1 Gigabit and Full duplex

There are two types of ISCSI initiators

Software based: Software based iSCSI initiators have a code built into VMKernel which carries out the transporting job, using software initiators, the ESX server connects to a LAN through an existing NIC card using network stacks, in short you can implement iSCSI without purchasing specialized hardware. You also need to open a firewall port by enabling the iSCSI software client service.

Hardware based : Hardware based iSCSI initiators: requires HBA cards which are specialized to transport iSCSI cmds over LAN to the target. Currently ESX Server supports only Qlogic QLA4010 iSCSI HBA.

Discovery methods

Static: Only available for Hardware based iSCSI initiators, you can manually add additional targets or remove unneeded targets. If you remove a dynamically discovery static target, the target can be returned to the list the next time a rescan happens, the HBA is reset, or the system is rebooted.

Dynamic: to use this method enter the address of the target device so that the initiator can established a discovery session with this target. The target device then responds by forwarding a list of additional targets that the initiator is allowed to access.

Failover

Active/Active = Fixed
Active/Passive = MRU

The initiators can use one of the following formats

IQN (iSCSI qualified name)
EUI (extended unique indentifier)

IQN can be up to 255 characters long and has the following format:

iqn.year-mo.unique_reversed_domain_name:unique_name,where year-mo represents the year and month your domain name was registered,reserved_domain_name

Authentication

ESX does not support Per-target credentials

The authentication type of iSCSI is CHAP (Challenge Handshake Authentication Protocol) only unidirectional CHAP authentication is supported.
Only one set of CHAP credentials per software initiator

Others

Max iSCSI LUNS: 8

Clustering is not official supported for iSCSI

---

bron: http://www.vmware.com/support/pubs/vi_pubs.html http://esxvmware.spaces.live.com/