iSCSI Switch Recommendations

[hutchingsp]

I'm looking at putting in an Equallogic PS4000E. Essentially for now we're talking a relatively low cost jump up from a "dumb" iSCSI array, using SATA disks for a specific requirement for bulk but low transaction storage.

In a year or so's time when our main SAN is replaced I'd be interested in getting a more highly specified Equallogic unit, using it as our primary box and moving our main production stuff onto it (we're nearly entirely virtualized already) and putting the PS4000 at the other end of our site as a replication/DR uni.

For now, whilst it's clearly best practise, I don't know if we actually need redundant switches, so what I'm looking for is recommendations on what may be a suitable switch to buy now, with a view to buying more from the same vendor if we standardize on Equallogic.

Dell PowerConnect are the obvious choice I guess. We already have a couple of 5424's in a rack servicing a "dumb" MD3000i at our DR site, we don't push them, they seem to do the job even if the web GUI does suck - I'm assuming they won't be sufficient should we end up utilizing EqualLogic heavily?

There seem to be lots of vendors out there from the names I know, Dell, Cisco, HP, then are lots of "niche" vendors - and I don't know what makes a good iSCSI switch.

We're currently on ESX 3.5 U4 and I would be expecting to be moving to vSphere when our main SAN and ESX boxes are replaced (essentially right now it aint broke so I'm not looking to fix it).

[sketchy00]

The 5424's are just fine for any of the Equallogic SAN's I run a couple of them against a PS5000 array. The nice part about the switches is that because they are blessed by Equallogic, they provide a nice little document spoonfeeding you the exact settings you need to use them. They aren't stackable, but if you trunk 3 or 4 ports, you'll be fine. They are a good lower cost alternative to more expensive switches.

And for something as critical as an iSCSI SAN, do you really want to put all of your eggs in one basket with one switch? ...never. Use two switches, and pat yourself on the back for doing the right thing.

[hutchingsp]

Thanks.That's quite re-assuring - we already have an iSCSI SAN at our DR site using a pair of 5424's but it's just a "dumb" MD3000i and I believe the switch config is totally different with Equallogic as whilst the switches provide redundancy you're using a single subnet for it all vs. the (to me) more familiar "Two Subnets" method.

Do you have a link to the documentation, as I've found a lot of papers outlining config but nothing that lists the actual config commands required (I manage/get by with switch config).

[sketchy00 · Accepted solution]

Yes, it's called the "Dell_Equallogic_Configuration_Guide.pdf" which I will attempt to attach. You will want to look at "Appendix B" In there, you will see the exact steps you need to make the changes. Just to make sure I could repeat the process if necessary, I made some as-built notes, which basically reflect the steps Dell gives. Oh, and make sure you save your new config. ...you wouldn't want anything embarrasing to happen.

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Changes needed for configuring switches for the Equallogic SAN.

Assumes one has typed in "enable" to elevate privledges.

1. Disable iSCSI optimization setting on all SAN switches.

Configure

No iscsi enable

Exit

Copy running-config startup-config

Exit

1. Enable "portfast" option to configure STP edge ports

Configure

Spanning-tree mode rstp

Interface ethernet g10 (and any other ports used for inter-switch connections)

Spanning-tree portfast

Exit

Exit

Copy running-config startup-config

Exit

1. Configure (enable) "flow control" (off by default)

Configure

Interface range ethernet g(1-48)

Speed 1000

Duplex full

Flowcontrol on

Exit

Exit

Copy running-config startup-config

Exit

1. Configure Storm Control (to disable it on all ports)

Configure

Interface range ethernet all

No port storm-control broadcast enable

Exit

Exit

Copy running-config startup-config

Exit

1. Configure (enable) jumbo frames

Configure

Port jumbo-frame

Exit

Copy running-config startup-config

Exit

1. Per the Equallogic quickstart guide, disable stp on all ports that don't trunk together the two switches. (p.10)

Link to the latest EqualLogic Configuration Guide:

http://www.delltechcenter.com/page/EqualLogicConfigurationGuide

[AndreTheGiant]

No iscsi enable

This tuning is very important on Equallogic cause PowerConnect 5xxx iSCSI optimization does not work well with Equallogic multi-path and load balancing.

Andre

[hutchingsp]

Brilliant, thanks for posting that - very useful and hopefully the "missing link" should we settle on the Equallogic.

[calmo]

The version of the Dell EqualLogic Configuration Guide attached to your reply above is out of date. Please delete the attachment file and replace with this link:

http://www.delltechcenter.com/page/EqualLogic Configuration Guide

We refresh the content in this publication once per quarter. By going to that page instead of uploading a current version you'll always get the latest version available.

Thanks!

Chris Almond, Storage Infrastructures and Solutions, Dell Product Group

[sketchy00]

I've adjusted the original response. Thanks Chris.

- Pete

[EllettIT]

If you want to stick with Dell you may want to look at the PowerConnect 62XX series, you'll drop the pre-configured iSCSI stuff and add a dedicated stacking bus. My company's transistion was from a single 5424 to 2 HP Procurve 2910al-24G's to 2 Cisco 3750X 48 port switches for our iSCSI traffic.

Config guide for PC 6224:

http://www.delltechcenter.com/thread/3521967/PowerConnect6224stackconfigurationfor+EqualLogic