A few days ago I had a chance to configure a Dell EqualLogic PS4000XV iSCSI SAN connected through two Dell PowerConnect 6224 switches during a virtualization project at one of our customers. Although the configuration of the switch is quite straightforward, there are some configuration settings that should be considered.
- Enable the Rapid Spanning Tree Protocol on the switch as well as the “spanning-tree portfast” feature on all ports connected to the SAN
- Enable Jumbo Frame support on ports connected to the SAN
- Disable the “storm control” feature on ports connected to the SAN
- Enable Flow Control on the switch
Follow these steps to configure the settings mentioned above:
- Enable RSTP and “spanning-tree portfast”. Login to the switch, enter the enable mode and then the configure mode.
- Configure the RSTP spanning tree: Switch(config)# spanning-tree mode rstp
- Enter the port configuration mode. In this case I’ll use port 1 to 12: Switch(config)# interface range ethernet 1/g1-1/g12
- Configure the “portfast” feature on the ports: Switch(config-if)# spanning-tree portfast
- Enable Jumbo Frames: Switch(config-if)# mtu 9216
- Disable storm control: Switch(config-if)# no storm-control unicast
- Return to the config mode by typing: Switch(config-if)# exit
- Enable Flow Control: Switch(config)# flowcontrol (you might be disconnected if you telneted to the switch, if so you can reconnect right away)
- Save the settings: Switch# copy running-config startup-config
- Log off the switch
And you’re done! 🙂
Cheers!
– Marek.Z
Great info really helped me out alot this AM when I was getting annoyed with Dell when I couldn’t find the settings my PS6000’s manual said to change. Thanks a lot!
That’s great Jack! I’m glad it helped 🙂
You mentioned two 6224s…what method did you use to connnect them in a redundant state?
Hi there,
Well, the switches were stacked through the 10G interface (XAUI) on the back.
Hi Marek,
We are also configuration two PC5448 and PS6000XV, however, we also use the two PC5448 for VMotion/COS/FT besides iSCSI.
I have a question regarding
“Enable the Rapid Spanning Tree Protocol on the switch as well as the “spanning-tree portfast” feature on all ports connected to the SAN”
As I understand edge-port means NON-LAG ports (ports doesn’t participate in LAG).
Does this simply mean after enabling RSTP on the switch, ALSO Enable spanning-tree Portfast on every ports (in my case VMotion/COS/FT/iSCSI), this RSTP Portfast feature is actually to disable RSTP on those edge ports right?
However, in the manual, it is said “PortFast” should be enable only on those ports being used for Inter-Switch Connection. (ie, LAG) Could it be a typo that the manual actually mean PortFast should be enabled ONLY for NON LAG?
Thanks,
Jack
Hi Jack,
AFAIK;
“Does this simply mean after enabling RSTP on the switch, ALSO Enable spanning-tree Portfast on every ports (in my case VMotion/COS/FT/iSCSI)” <- No, Portfast is per port setting (enable it for your vMotion/COS/FT/iSCSI).
"…this RSTP Portfast feature is actually to disable RSTP on those edge ports right?" <- Not really, it will put the port directly in the forwarding state and not the default blocking/listening/learning/forwarding state.
The portfast feature MUST be enabled otherwise you will end up with inconsistent paths to your storage array.
hth
Cheers!
Marek.Z
P.s. Too bad, I do not have access to those switches anymore, so I cannot test this for you 🙁
Hello,
Just a precision, if the 2 switchs are dedicated to the SAN, STP/RSTP must be disable :
Like “PS Series Network Performance Guidelines.pdf explain it : If possible, do not use STP on switch ports that connect end nodes (iSCSI initiators
or storage array network interfaces).
Because STP can increase the time it takes to recover from a PS Series array control module
failover or a network switch failure, Dell recommends that you do not use STP on switch ports that
connect end nodes”
Hi,
At the time of writing this article, the best practice from Dell was to use the RSTP setting for the storage switches. Probably this changed over the years, I haven’t looked it up. But yes, in most cases the best practice is to disable STP completely, keep in mind however that this leaves your storage switches prone to “human error”.
Cheers!