VM-Aware » Brocade

Brocade New Features

Paul Shannon — Tue, 24 Feb 2009 22:14:56 +0000

As someone that implements Brocades SANs on a semi-regular basis, I thought I’d stop by their stand and see if they had anything interesting on show and it turns out they did.

The project I am currently working on has a number of Brocade fabrics (4) after adding 3 new ones and managing them would have been a pain if not for Data Center Fabric Manger. However, there is one massive limitation with DCFM and that’s the free version only manages a single fabric. ‘What do you expect for free?’ I hear you cry, well I expect the jump up from the free version to be a bit more incremental than it currently is. If you want to upgrade you can, to the Enterprise, which will cost you a substantial £30k list. Now this is not bad if you push Enterprise to its limits (1000 ports in a single fabric), but what if you only have 200 ports? well Brocade have obviously noticed this discrepency and are releasing a middle level version and are hoping to release in the next few months.

Something else of interest was the vCenter plugin that connects directly with Data Centere Fabric Manager and can trigger actions within vCenter based on policies set at the fabric level. If an HBA’s bandwidth becomes saturated, a policy can send an alert to vCenter to move it to a host with greater HBA bandwidth availability.

All very neat stuff and the demo worked, so check it out if you deal with Brocade kit.

Rescan SAN Extremely Slow

Paul Shannon — Tue, 15 Jul 2008 07:56:43 +0000

I recently came across a problem whereby a Rescan SAN was taking an absolute age, like 15 minutes from the VI Client. Now I love the VI Client, but sometimes it just doesn’t give you enough information when it is doing things. To be fair most of the time the verbose information is simply not needed, but when things go wrong it is a god send.

In comes the Service Console command line, more specifically the esxcfg-rescan and esxcfg-mpath commands.

Firstly I ran esxcfg-mpath -l, which will list all the LUNs and the paths associated with each LUN. After running this I noticed that some of the LUNs had dead paths listed for LUNs that had been deleted from both the Storage Processor (DataCore) and the VI Client.

I had previously read somewhere (I can’t remember where) that Brocade switches can sometimes cause ESX to remember LUN locations even if they have been removed from the Storage Processor. So this meant that I had to routes to take 1 – Add the LUN back with the original paths and try and remove again gracefully or 2 -reboot the ESX host.

The second option was not really desirable as far as the customer was concerned so I had to go and add the LUNs back. This wasn’t such a big deal, but here’s what I did:

Create the LUN in DataCore
Set up mirroring to create the original 4 paths
Present the storage to both the affected ESX hosts
Run esxcfg-rescan vmhba?? on both HBAs
Use esxcfg-mpath -l to check that the original paths are now showing as either Active or On and that there are no Dead paths
Open the VI Client and add the LUNs using the Add Storage wizard
Now remove the LUNs from the VI Client
Run esxcfg-mpath -l to make sure that all the paths are still happy
Go back to the Storage Processor and remove the LUNs presented to the ESX hosts
finally run esxcfg-rescan vmhba?? on both HBAs again and check that the LUNs have been removed and that there are no Dead paths to any of the LUNs

I know all this seems a little long winded, but it was at the time not desirable to reboot the ESX hosts.

Here is a good Tech Note from VMware to help with the use of esxcfg-mpath.

Brocade & ESX – Updating Effective Config

Paul Shannon — Thu, 10 Jul 2008 15:20:14 +0000

I don’t know if you are like me and feel initially a little bit nervous about messages that contain phrases like “there may be some interruption to I/O”.

Useful Brocade Switch Telnet Commands

Paul Shannon — Wed, 16 Apr 2008 10:06:01 +0000

Anybody using Brocade Fibre Switches on a regular basis will notice that sometimes the web interface can sometimes be, shall we say funky!

It sometimes show defragmented fabric in the web browser, but there is no reason for it etc.

Here’s an overview of some useful commands that you can execute from the Telnet command line:

switchshow

zonecreate “sw1zone1″, “1,12; 1,14; 1,15″

cfgcreate “sw1cfg1″, “sw1zone1″

cfgenable “sw1cfg1″

reboot

Zones Zone has two memory areas
Effective Zone
Config Zone

zoneshow show the current zones

zonehelp help on the various zone commands

zoneadd add switch ports to a particular Zone

zoneremove remove ports from a zone

cfgsave to save changes you make to the Zone Configuration

cfgenable make the saved config changes effective immediately

cfgshow display the current Zones