Understanding VMWare & iSCSI
Notes Paths
Basic iSCSI Configuration v3.5
•Single iSCSI Enabled VMKernel Port • 10.1.1.1 to 10.1.1.101
•Single vSwitch
Single Path – No Load Balancing •Default NIC Teaming (Route Based) There is only a single path
Network (Layer 2) based Failover (Fast) •Storage has single Virtual IP v3.5 will only allow a single initiator:target connection
** I think that this is the most reliable ** •Teaming could be failover or LACP Even with LACP or Etherchannel there will only be a
single path as the IP addresses never change.
** Let the network layer handle failover ** •Works with all
vSwitch
vmnic1
VMKernel Port
ISCSI
10.1.1.1
Single Virtual IP
10.1.1.101
vmnic2
vSwitch
vmnic1
VMKernel Port
ISCSI
10.1.1.1
Single Virtual IP
10.1.1.101
vmnic2
Understanding VMWare & iSCSI
Notes Paths
Basic iSCSI Configuration v3.5
•Single iSCSI Enabled VMKernel Port • 10.1.1.1 to 10.1.1.101
•Single vSwitch • 10.1.1.1 to 10.1.1.102
Dual Path – No Load Balancing •Default NIC Teaming (Route Based)
Network (Layer 2) based Failover (Fast) •Storage has two Virtual IPs
There are 2 paths, but no load balancing
IP (Layer 3) based Failover (Slow ~ 60sec) •The IPs are fixed to the adaptors v3.5 will only allow a single initiator:target connection
v4 may allow both paths to be active, but not working in
•ESX Server hangs on storage NIC failure test
vSwitch
vmnic1
VMKernel Port
Virtual IP #1
ISCSI
10.1.1.1 10.1.1.101
Virtual IP #2
10.1.1.102
vmnic2
vSwitch
vmnic1
VMKernel Port
Virtual IP #1
ISCSI
10.1.1.1 10.1.1.101
Virtual IP #2
10.1.1.102
vmnic2
Understanding VMWare & iSCSI
Notes Paths
Advanced iSCSI Configuration v4.0
•Two iSCSI Enabled VMKernel Port • 10.1.1.1 to 10.1.1.101
•Single vSwitch • 10.1.1.2 to 10.1.1.101
Sinlge VLAN •NIC Teaming overridden
Multipath I/O – Load Balancing •1:1 Mapping of VMKernel to NIC There are 2 paths, with load balancing at ESX side
NO Layer 2 failover at ESX side, only IP Path selection
IP (Layer 3) based Failover (Slow ~ 60sec) •Storage has single Virtual IP
•Teaming could be failover or LACP LACP or Etherchannel may allow some load balancing on
the storage side
vSwitch •Works with FreeNAS, not Thecus
vmnic1
VMKernel Port
ISCSI
10.1.1.1
VMKernel Port Single Virtual IP
ISCSI-2 10.1.1.101
10.1.1.2
vmnic2
vSwitch
vmnic1
VMKernel Port
ISCSI
10.1.1.1
VMKernel Port Single Virtual IP
ISCSI-2 10.1.1.101
10.1.1.2
vmnic2
Understanding VMWare & iSCSI
Notes Paths
Advanced iSCSI Configuration v4.0
•Two iSCSI Enabled VMKernel Port • 10.1.1.1 to 10.1.1.101 10.1.1.1 to 10.1.1.102
•Single vSwitch • 10.1.1.2 to 10.1.1.101 10.1.1.2 to 10.1.1.102
Sinlge VLAN •NIC Teaming overridden
Multipath I/O – Load Balancing •1:1 Mapping of VMKernel to NIC There are 4 paths, with load balancing
NO Layer 2 failover at ESX side, only IP Path selection
IP (Layer 3) based Failover (Slow ~ 60sec) •Storage has two Virtual IPs NO Layer 2 failover at storage side
•The IPs are fixed to the adaptors
Does Not working in testing – Multiplexing Bad…
vSwitch •ESX Server hangs on storage NIC failure
vmnic1
VMKernel Port
Virtual IP #1
ISCSI
10.1.1.1 10.1.1.101
VMKernel Port
ISCSI-2 Virtual IP #2
10.1.1.102
10.1.1.2
vmnic2
vSwitch
vmnic1
VMKernel Port
Virtual IP #1
ISCSI
10.1.1.1 10.1.1.101
VMKernel Port
ISCSI-2 Virtual IP #2
10.1.1.102
10.1.1.2
vmnic2
Understanding VMWare & iSCSI
Notes Paths
Advanced iSCSI Configuration v4.0
•Two iSCSI Enabled VMKernel Port • 10.1.1.1 to 10.1.1.101
•Single vSwitch • 10.1.254.1 to 10.1.254.101
Dual VLAN •NIC Teaming overridden
Multipath I/O – Load Balancing •1:1 Mapping of VMKernel to NIC There are 2 paths, with load balancing
NO Layer 2 failover at ESX side, only IP Path selection
IP (Layer 3) based Failover (Slow ~ 60sec) •Storage has two Virtual IPs NO Layer 2 failover at storage side
•The IPs are fixed to the adaptors
** This is best compromise for throughput **
vSwitch •Works in FreeNAS, failover is slow
•Have to use Static iSCSI Targets
vmnic1 VLAN 1
VMKernel Port
Virtual IP #1
ISCSI
10.1.1.1 10.1.1.101
VLAN 254
VMKernel Port
ISCSI-2 Virtual IP #2
10.1.1.101
10.1.254.1
vmnic2
vSwitch
vmnic1 VLAN 1
VMKernel Port
Virtual IP #1
ISCSI
10.1.1.1 10.1.1.101
VLAN 254
VMKernel Port
ISCSI-2 Virtual IP #2
10.1.254.101
10.1.254.1
vmnic2