How about some details on this Virtual Media Repository? As a new Linux administrator, you're probably not going to need to know a lot of the details, but rather that the physical media repository feature exists and that you can use it because you might want to use it. But in this video, I'm going to give you some of the details, how you create and manage the repository. Recall, I said that the media repository was based on a file system in the VIOS. The file system name was displayed in the previous video, but I didn't mention the directory specifically. Let me do that here. The file system is called "/var/vio/ VMLibrary," where the V-M-L are uppercase. One file system to support this feature means that there's only one Virtual Media Repository per VIOS, and since it's on a VIOS, and a VIOS is unique to a physical server, the Virtual Media Repository is accessible by all parts that are on the same physical server as the VIOS with the Virtual Media Repository. I think it's useful to see what that file system looks like on a system. Again, be careful here. I'm using the special command "oem_setup_env" on the VIOS server. That gives me root access from the Restricted Administrator ID. The extracted optical media or the ISO files will be in that directory I mentioned earlier, and write permission for the owner on any file indicates that that media is read-write, or basically it's a DVD-RAM and can be loaded to just one virtual optical drive at a time. Now, no-write permission, just read-only on the media file, indicates that this media file acts as a DVD-ROM, allowing multiple LPARs to share the media at the same time. Now, again, please don't expect to access the files like this unless you're having problems with the virtual media repository. Use the commands available for Virtual Media Repository management. I just wanted to show you what that file system looks like. So for the rest of the video, I'll explain how to create and manage the VMR. I'm going to go through this pretty quickly. I chose to show you the methods that use the VIOS CLI rather than the HMC. The VIOS CLI has been around and available since the feature was released back in the early 2000s, and using the HMC is heavily documented today. So I thought it would be helpful for you to see things behind the scenes a bit to enhance your understanding. Keep in mind, using the HMC is still easier than what you're going to see here. But this is good, it's good to see how all of this goes together. I guess I'm going to go quickly, but see if you can follow along. So the first step is to create the volume group in the VIOS that will contain the file system, and eventually the optical media files. Now, the VIOS root volume group can be used, in which case this step is skipped, but I don't recommend that. Now, you want to name the new volume group, something like repvg, so you know how it's being used. You'll specify the available disk or discs on which the volume group will be based, and notice that it's technically called a logical volume storage pool in the VIOS, and the command is mksp. It's truly a volume group defined in the AIX operating system on the VIOS, so you could use to make VG command. Your next step is to create the repository, and that's done using the mkrep command. This is really just a file system in the volume group created in the previous step. You specify the volume group as an argument on the -sp flag. The size specified with the -size flag does not have to be the same as the disk space available, but since you won't be using that volume group for anything else, I always use all available space or nearly all. As in the example, I specified the size in gigabytes, the G in 10G, but M is also available as in 1001 to 1012M for gigabyte. Now, to fill the repository with optical media use, you use the mkvopt command. This command extracts and copies an ISO image into the file system as a media file. In the first example, the ISO image is being extracted from a physical optical drive. Note the use of the -dev flag with the physical device name as an argument. The second example is what I nearly always do, copying an already extracted ISO file from an external source, usually an NFS mount into the repository. Note the use of the -file flag with the name of the ISO file as an argument. Now, in both cases I made the media read-only, so multiple LPARS can share it. But the -rw flag could have been used, especially in the first example to make the media file writable. So what's next? We have a storage-based volume group in the file system created, and we have at least one media file in the repository for use by an LPAR. So thinking back, we need a virtual optical device on the LPAR /dev/sr0 device. To do that, you use the mkvdev command with the -fbo flag, File-Backed Optical. FBO, File Backed Optical. This command creates a new virtual optical device on the VIOS that maps to a new virtual optical device on the LPAR. You can give it a descriptive name using the -dev flag, or let the system generate a name, as you see in the graphic. A quick discovery operation is required in the LPAR to pick up the new optical device, and from that point on, it's really ready to be used. Now, in our example, there was some background setup already completed. What is unseen is the configuration of the virtual SCSI adapter vhost0 on the VIOS, as well as the partner virtual SCSI adapter configured on the LPAR. Now, all that's left is to load the media file into the virtual optical drive. Think of this operation as putting a CD or a DVD into a CD or DVD drive. The LPAR will be able to access and use that media as though it was a physical optical disk in a physical optical media. I'll close out the video with a couple of commands that you can use to see the status of the repository, including loaded media files and the virtual optical drives, again, including loaded media files. Now, have a look at the graphic. You see lsrep providing repository status. An important field to monitor is the Free(mb) column. It tells you how much space is left in the repository, the file system that is. If you're running out of space, have a look at the Parent Free column which tells you how much is in the storage pool, the volume group that is. Now, if there is available space there, you can expand the repository to accommodate more media files. Otherwise, you're going to have to add more disks to the storage pool, to the volume group, to create more space. If you're curious about what media files are loaded in which virtual optical drives, the lsrep showed you what media files are available, but didn't show you where they were loaded, the lsvopt command provides that information.
