One of the cool new items in v.10 is the use of a logical volume manager (LVM) to create and manage multiple “partitions”. This is the last time I will use the term “partition” to refer to v.10 disk space in this post, since partitioning was the way things were done prior to v.10, moving forward we use the volume system.

Considerations

The first thing to do is decide if LVM is the right tool for you. Like most massively cool technologies, it supersedes the system it is designed to replace. While we do our best to provide backward compatibility, this is one instance where the systems were different enough that we settled on an “either/or” version of backward compatibility. Thus, if you intend to continue using version 9.x products, you should not install LVM. The benefits of LVM are legion, but due to its adaptability, it does not sit well on the same machine as version 9 partitioning. The best bet is to check and make certain you can/have upgraded all of your modules, and then proceed if you are prepared to completely replace your systems with v.10 systems. You can run v.10 in a 9.x partition, more on that in a moment.

Preparation

Lets be straight-up about this, I’m not trying to give you a complete set of installation instructions in a blog post, we have an excellent technical publications group that covers this in Chapter Two of our Getting Started Guide (ask.f5.com login required), there’s no reason for me to reinvent wheel when they have done the work of figuring it out and documenting it for you step by step. But I do want to give you an idea of what to expect when you upgrade your system for v.10 and that includes installing LVM and volumes.

First off, you have to use the img2disk utility to transfer the lvm and system volumes to the BIG-IP. There are good instructions on that in Appendix A of the Getting Started Guide. If you think you have a very good reason for running 9.x and v.10 on the same BIG-IP, there are instructions for how to do that also. In this scenario, LVM is not used, so it is outside the scope of this blog post. The short list of items required to get this done is

1. Download the 10.x iso
2. us im to transfer the iso to disk
3. use image2disk to install and set up basic volumes
4. from the Web GUI run the configuration utility

That’s it. Of course “run the configuration utility” has a bunch of options, you can create, delete, rename, make active, and install volumes, but all of this is well covered in the Getting Started Guide.

Usefulness

Now we come to the meat of the discussion where most of us are concerned – all this rigmarole, what do we get out of it? Well, some modules in the future will utilize configured volumes for things like swap space, but in the short term, the big benefit is that you can maintain multiple versions of v.10 on your BIG-IP. That means that you can have one configuration ready to roll if testing bears out its usefulness and another running production. If you only have one set of BIG-IPs and want to test the upgrade to 10.0.9, for example (no, 10.0.9 doesn’t exist as of this writing, I’m looking forward), you can configure it on a separate volume, and during your scheduled testing period, reboot the BIG-IP to run off of that volume. When testing is done, you can either leave it running on the new version (don’t forget to set that to be the active or “boot” volume!), or you can reboot and come back to the old version.

That also means that you can make a build with your current configuration, test license a module (see Jeff’s article for more on this topic), and if it works, just run off the new volume, if it causes you unforeseen issues, reboot to the old one – but you can keep the one you’re not using around, there’s no longer a limitation (other than available disk space) on the number of partitions/volumes you can have on the disk.

Conclusions

This is a useful set of tools that from a user perspective expands what is already available, and from a module perspective, expands what can be offered to users. All in all I think we’ll see more and more uses for LVM to come about as DevCentral users get out there and install it. Auto switching between volumes based upon events seems possible, though I can’t for the life of me imagine why you’d want to, someone will find a good reason. It might even be a reason that makes us all go “Heyyy…”

I haven’t actually installed v.10 on Lori and I’s box yet, but it’s coming – I have a project rooted in 9.x that has to be cleared up first – and then we’ll start playing more with LVM. After that I’ll circle back and offer you all an update.

Until next time,

Don.

Categories: v.10 , DevCentral , Monitoring/Management