Upgrade the firmware on a Brocade Fibre Channel Switch

NOTE: content available as pdf download here.

Upgrade the firmware on a Brocade Fibre Channel Switch

In order to maintain a secure, well-functioning fibre channel fabric over the years you’ll need to perform a firmware upgrade now and again. Brocade fibre channel switches are expensive but they do deliver a very solid experience. This experience is also obvious in the firmware upgrade process. We’ll walk through this as a guide on how to upgrade the firmware on a Brocade fibre channel switch environment.

Have a FTP/SFTP/SCP server in place

If you have some switches in your environment you’re probably already running a TFTP or FTP server for upgrading those. For TFTP I use the free but simple and good one provided by Solarwinds. They also offer a free SCP/SFTP solution. For FTP it depends either we have IIS with FTP (and FTPS) set up or we use FileZilla FTP Server which also offers SFTP and FTPS. In any case this is not a blog about these solutions. If you’re responsible for keeping network gear in tip top shape you should this little piece of infrastructure set up for both downloads and uploads of configurations (backup/restore), firmware and boot code. If you don’t have this, it’s about time you set one up sport! A virtual machine will do just fine and we back it up as well as we store our firmware and backups on that VM as well. For mobile scenarios I just keep TFTP & FilleZilla Server installed and ready to go on my laptop in a stopped state until I need ‘m.

Getting the correct Fabric OS firmware

It’s up to your SAN & switch vendors to inform you about support for firmware releases. Some OEMs will publish those on their own support sites some will coordinate with Brocade to deliver them as download for specific models sold and supported by them. Dell does this. To get it select your switch version on the dell support site and under downloads you’ll find a link.

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That link takes you to the Brocade download page for DELL customers.

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Make sure you download the correct firmware for your switch. Read the release notes and make sure you’re the hardware you use is supported. Do your homework, go through the Brocade Fabric OS (FOS) 7.x Compatibility Matrix. There is no reason to shoot yourself in the foot when this can be avoided. I always contact DELL Compellent CoPilot support to verify the version is support with the Compellent Storage Center firmware.

When you have downloaded the firmware for your operating system (I’m on Windows) unzip it and place the content of the resulting folder in your FTP root or desired folder. I tend to put the active firmware under the root and archive older one as they get replaced. So that root looks like this. You can copy it there over RDP or via a FTP client. If the FTP server is running your laptop, it’s just a local copy.

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The upgrade process

A word on upgrading the firmware

I you move from a single major level/version to the next or upgrade within a single major level/version you can do non-disruptive upgrades with a High Availability (HA) reboot meaning that while the switch reloads it will not impact the data flow, the FC ports stay online. Everything keeps running, bar that you lose connectivity to the switch console for a short time.

Some non-disruptive upgrade examples:

V6.3.2e to V6.4.3g

V7.4.0a to v7.4.0b

V7.3.0c to v7.4.0b

Note that this way you can step from and old version to a new one step by step without ever needing downtime. I have always found this a really cool capability.

You can find Brocades recommendations on what the desired version of a major release is in https://www.brocade.com/content/dam/common/documents/content-types/target-path-selection-guide/brocade-fos-target-path.pdf

I tend to way a bit with the latest as the newer ones need some wrinkles taken care of as we can see now switch 7.4.1 which is susceptible to memory leaks.

Some disruptive upgrade examples (FC ports go down):

7.1.2b to 7.4.0a

6.4.3.h to 7.4.0b

Our upgrade here from 7.4.0a to 7.4.0b is non-disruptive as was the upgrade from to 7.3.0c to 7.4.0a. You can jump between version more than one version but it will require a reboot that takes the switch out of action. Not a huge issue if you have (and you should) to redundant fabrics but it can be avoided by moving between versions one at the time. IT takes longer but it’s totally non-disruptive which I consider a good thing in production. I reserve disruptive upgrades for green field scenarios or new switches that will be added to the fabric after I’m done upgrading.

Prior to the upgrade

There is no need to run a copy run or write memory on a brocade FC switch. It persists what you do and you have to save and activate your zoning configuration anyway when you configure those (cfgsave). All other changes are persisted automatically. So in that regards you should be all good to go.

Make a backup copy of your configuration as is. This gives you a way out if the shit hits the fan and you need to restore to a switch you had to reset or so. Don’t forget to do this for the switches in both fabrics, which normally you have in production!

You log on switch with your username and password over telnet or ssh (I use putty or kitty)

MySwitchName:admin> configupload

Hit ENTER

Select the protocol of the backup target server you are using

Protocol (scp, ftp, sftp, local) [ftp]: ftp

Hit ENTER

Server Name or IP Address [host]: 10.1.1.12

HIT ENTER

Enter the user, here I’m using anonymous

User Name [user]: anonymous

Hit ENTER

Give the backup file a clear and identifying name

Path/Filename [<home dir>/config.txt]: MySwitchNameConfig20151208.txt

Hit ENTER

Select all (default)

Section (all|chassis|switch [all]): all

configUpload complete: All selected config parameters are uploaded

That’s it. You can verify you have a readable backup file on your FTP server now.

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The Upgrade

A production environment normally has 2 fabrics for redundancy. Each fabric exists out of 1 or more switches. It’s wise to start with one fabric and complete the upgrade there. Only after all is proven well there should you move on to the second fabric. To avoid any impact on production I tend plan these early or late in the day also avoiding any backup activity. Depending on your environment you could see some connectivity drops on any FC-IP links (remote SAN replication FC to IP ó IP to FC) but when you work one fabric at the time you can mitigate this during production hours via redundancy.

Log on to first brocade fabric switch with your username and password over telnet or ssh (I use putty or kitty). At the console prompt type

firmwaredownload

This is the command for the non-disruptive upgrade. If you need or want to do a disruptive one, you’ll need to use firmwaredownload –s.

Hit Enter

Enter the IP address of the FTP server (of the name if you have name resolution set up and working)

Server Name or IP address: 10.1.1.12

User name: I fill out anonymous as this gives me the best results. Leaving it blank doesn’t always work depending on your FTP server.

User Name: anonymous

Enter the path to the firmware, I placed the firmware folder in the root of the FTP server so that is

Path: /v7.4.0b

Hit enter

At the password prompt leave the password empty. Anonymous FTP doesn’t need one.

Password:

Hit enter, the upgrade process preparation starts. After the checks have passed you’ll be asked if you want to continue. We enter Y for yes and hit Enter. The firmware download starts and you’ll see lost of packages being downloaded. Just let it run.

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This goes on for a while. At one point you’ll see the prom update happening.clip_image011

When it’s done it starts removing unneeded files and when done it will inform you that the download is done and the HA rebooting starts. HA stands for high availability. Basically it fails over to the next CP (Control Processor, see http://www.brocade.com/content/html/en/software-upgrade-guide/FOS_740_UPGRADE/GUID-20EC78ED-FA91-4CA6-9044-E6700F4A5DA1.html) while the other one reboots and loads the new firmware. All this happens while data traffic keeps flowing through the switch. Pretty neat.

When you keep a continuous ping to the FC switch running during the HA reboot you’ll see a short drop in connectivity.

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But do realize that since this is a HA reboot the data traffic is not interrupted at all. When you get connectivity back you SSH to switch and verify the reported version, which here is now 7.4.0b.

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That’s it. Move on to the switch in the same fabric until you’re done. But stop there before you move on to your second fabric (failure domain). It pays to go slow with firmware upgrades in an existing environment.

This doesn’t just mean waiting a while before installing the very latest firmware to see whether any issues pop up in the forums. It also means you should upgrade one fabric at the time and evaluate the effects. If no problems arise, you can move on with the second fabric. By doing so you will always have a functional fabric even if you need to bring down the other one in order to resolve an issue.

On the other hand, don’t leave fabrics unattended for years. Even if you have no functional issues, bugs are getting fixed and perhaps more importantly security issues are addressed as well as browser and Java issues for GUI management. I do wish that the 6.4.x series of the firmware got an update in order for it to work well with Java 8.x.

Hyper-V UNMAP Does Work With SAN Snapshots And Checkpoints But Not Always As You First Expect

Recently I was asked to take a look at why UNMAP was not working predictably  in a Windows Server 2012 R2 Hyper-V environment. No, this is not a horror story about bugs or bad storage solutions. Fortunately, once the horror option was of the table I had a pretty good idea what might be the cause.

San snapshots are in play

As it turned out everything was indeed working just fine. The unexpected behavior that made it seem that UNMAP wasn’t working well or at least at moments they didn’t expected it was caused by the SAN snapshots. Once you know how this works you’ll find that UNMAP does indeed work predictably.

Snapshots on SANs are used for automatic data tiering, data protection and various other use cases. As long as those snapshots live, and as such the data in them, UNMAP/Trim will not free up space on the SAN with thinly provisioned LUNs. This is logical, as the data is still stored on the SAN for those snapshots, hard deleting it form the VM or host has no impact on the storage the SAN uses until those snapshots are deleted or expire. Only what happens in the active portion is directly impacted.

An example

  • Take a VM with a dynamically expanding VHDX that’s empty and mapped to drive letter D. Note the file size of the VHDX and the space consumed on the thinly provisioned SAN LUN where it resides.
  • Create 30GB of data in that dynamically expanding  virtual hard disk of the virtual machine
  • Create a SAN snapshot
  • Shift + Delete that 30GB of data from the dynamically expanding virtual hard disk in the virtual machine. Watch the dynamically expanding VHDX  grow in size, just like the space consumed on the SAN
  • Run Optimize-Volume D –retrim to force UNMAP and watch the space consumed of the Size of the LUN on the SAN: it remains +/- the same.
  • Shut down the VM and look at the size of the dynamic VHDX file. It shrinks to the size before you copied the data into it.
  • Boot the VM again and copy 30GB of data to the dynamically expanding VHDX in the VM again.
  • See the size of the VHDX grow and notice that the space consumed on the SAN for that LUN goes up as well.
  • Shift + Delete that 30GB of data from the dynamically expanding  virtual hard disk in the virtual machine
  • Run Optimize-Volume D –retrim to force UNMAP and watch the space consumed of the Size of the LUN on the SAN: It drops, as the data you delete is in the active part of your LUN (the second 30GB you copied), but it will not drop any more than this as the data kept safe in the frozen snapshot of the LUN is remains there (the first 30GB you copied)
  • When you expire/delete that snapshot on the SAN  we’ll see the size on the thinly provisioned SAN LUN  drop to the initial size of this exercise.

I hope this example gave you some insights into the behavior

Conclusion

So people who have snapshot based automatic data tiering, data protection etc. active in their Hyper-V environment and don’t see any results at all should check those snapshot schedules & live times. When you take them into consideration you’ll see that UNMAP does work predictably, all be it in a “delayed” fashion Smile.

The same goes for Hyper-V checkpoints (formerly known as snapshots). When you create a checkpoint the VHDX is kept and you are writing to a avhdx (differencing disk) meaning that any UNMAP activity will only reflect on data in the active avhdx file and not in the “frozen” parent file.

ODX Speed Up VHDX Creation Times On Windows Server 2012 (R2)

Some technlogies you just need to see in action instead of reading about it. I have posted a video on Vimeo that shows ODX in action on Windows Server 2012 R2 and a DELL Compellent SAN running Storage Center 6.3.10 firmware that supports UNMAP & ODX. Watch the video here or on Vimeo itself for a better experience. It’s a rerun of the demo scripts used in my TechNet Belux Live Meeting of this week.

We demonstrate the amazing speeds at which we can create VHDX files on both a traditional clustered disk and a Cluster Shared Volume. If you have ever tried to create a lot of fixed VHD/VHDX files, especially larger one, then you really need to check out ODX and its potential. If you have a SAN or think about acquiring one make sure you get this feature and be sure that it works as advertised.

I hope you enjoy it and inspires you to look where you can leverage this technology in your own environments.

Mind the UNMAP Impact On Performance In Certain Scenarios

The Problem

Recently we’ve been trouble shooting some weird SQL Server to file backup issues. They started failing on the clock at 06:00 AM. We checked the NICs, the switches, the drivers, the LUNs, HBAs, … but it was all well. We considered over stressed buffers as the root cause or spanning tree issues but the clock steadiness of it all was weird. We tried playing with some time out parameters but with little to no avail. Until the moment it hit me, the file deletions that clean up the old backups!We had UNMAP enabled recently on the SAN.

Take a look at the screenshot below an note the deletion times underlined in red. That’s with UNMAP enabled. Above is with UNMAP disabled. The Backup jobs failed waiting for the deletion process.

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This is a no issues if your backup target is running something prior to Windows Server 2012. if not, UNMAP is disabled by default. I know about the potential performance impact of UNMAP when deleting or more larger files due to the space reclamation kicking in. This is described here Plan and Deploy Thin Provisioning under the heading “Consider space reclamation and potential performance impact”. But as I’m quite used to talking about many, many terabytes of data I kind of forget to think of 500 to 600GB of files as “big” Embarrassed smile. But it seemed to a suspect so we tested certain scenarios and bingo!

Solutions

  1. Disable the file-delete notification that triggers real-time space reclamation. Find the following value HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControlFileSystemDisableDeleteNotification and set it to 1.

    Note that: This setting is host wide, so for all LUNs. Perhaps that server has many other roles or needs to server that could benefit from UNMAP. If not this is not an issue.  It is however very efficient in avoiding issues. You can still use the Defragment and Optimize Drives tool to perform space reclamation on-demand or on a scheduled basis.

  2. Create LUNs that will have high deltas in a short time frame as fully provisioned LUNs (aka thick LUNs). As you do this per LUN and not on the host it allows for more fine grained actions than disabling UNMAP.  It makes no sense to have UNMAP do it’s work to reclaim the free space that deleting data created when you’ll just be filling up that space again in the next 24 hours in an endless cycle. Backup targets are a perfect example of this. This avoid the entire UNMAP cycle and you won’t mind as it doesn’t make much sense and fixes you issue. The drawback is you can’t do this for an existing volumes. So it has some overhead & downtime involved depending on the SAN solution you use. It also means that you have to convince you storage admins to give you fully provisioned LUNs, which might or might not be easy depending on how things are organized.

Conclusion

UNMAP has many benefits both in the physical and virtual layer. As with all technologies you have to understand its capabilities, requirements, benefits and draw backs. Without this you might run into trouble.