Storage Groups - don't understand documentation

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hedgehog52
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Storage Groups - don't understand documentation

Post by hedgehog52 »

In the documentation (link to page below) it stresses that storage groups should only be defined on the master server. Then it goes on to give an example that makes no sense to me. I have 4 multi-TB drives that I want to store my data on. Three of them are on the master server, with the mount points: /Video, /Video2, and /Video3. I want to add /Video4 on the slave server. Do I need to add a "/Video4" directory with no subdirectories on the master server so that it knows that it should have a "/Video4" and since it's not on the master, it should look at all the slaves? If that's not what it means, then I just do not get it. In the past I've used nfs, but this isn't nfs.

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https://www.mythtv.org/wiki/Setup_Storage_Directories
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kmdewaal
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Re: Storage Groups - don't understand documentation

Post by kmdewaal »

Do I need to add a "/Video4" directory with no subdirectories on the master server so that it knows that it should have a "/Video4" and since it's not on the master, it should look at all the slaves?
Yes, that is how I understand it. You need to create the /Video4 directory on the master server also otherwise you cannot add it to the storage groups.
hedgehog52
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Re: Storage Groups - don't understand documentation

Post by hedgehog52 »

kmdewaal wrote:
Thu Aug 11, 2022 5:39 pm
Do I need to add a "/Video4" directory with no subdirectories on the master server so that it knows that it should have a "/Video4" and since it's not on the master, it should look at all the slaves?
Yes, that is how I understand it. You need to create the /Video4 directory on the master server also otherwise you cannot add it to the storage groups.
Thanks for the reply! I did some experiments with that, and I didn't get what I expected. But I'll do it again and see what happens now that I've had a chance to think about it some more. OTOH, if I define /Video4/etc only on the slave server (and not on the master server), the master frontend sees "/Video4/MythTV/Default" in the Information Center. But I haven't done any real testing on that to see if it actually works, as I've been concentrating more on trying to get the HDPVR on the slave system to work. I feel like I'm >< this close to getting all this working! :)
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kmdewaal
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Re: Storage Groups - don't understand documentation

Post by kmdewaal »

The next paragraph in the Wiki however does say this:
If you put a mount point directory name into an SG directory list, MythTV cannot tell when the file system is not mounted (the mount point and the mounted file system directory are identical), so it will gladly write to the parent file system (and possibly fill it up--which is very bad if the parent file system is the system's root file system). Instead, always create one or more subdirectories within your file systems and put a subdirectory path into the SG directory list. Then, when the file system isn't mounted, the directory doesn't exist, so MythTV will ignore it.
I did just now experiment a bit with this and it looks like the mythtv-setup Storage Group editor does not allow you to add a non-existing directory. I confess to also being a bit confused about this. If you have it working please report so we can update the Wiki (or fix the code if you do not get it working...).
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paulh
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Re: Storage Groups - don't understand documentation

Post by paulh »

It's a long time since I played with a slave backend so my recollections may be wrong but I think you do not have to add the storage group on the master but you do have to run mythtv-setup on the slave and add it here the same as you have to add tuners or video/music sttorage groups etc available one the slave.
hedgehog52
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Re: Storage Groups - don't understand documentation

Post by hedgehog52 »

Thanks for chiming in paulh! I've come to the same conclusion. But something I've done to the slave backend is now messing everything up. I may have to uninstall on the slave machine and start over. The problem is some sort of networking conflict. If I have the slave backend active, the frontend on the slave machine can't see the master backend, and so can't even show videos. In spite of this, somehow, I think I've made some progress, at least in my understanding. But I may just wind up moving both STBs to the master machine and do all the captures there. Hmm, logistically that's a problem, so I may have to swap which machine is master and which is slave. I never watch live TV anymore, anyway. I'm going to just let this stew a bit in my mind and get back to it in a few days.
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paulh
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Re: Storage Groups - don't understand documentation

Post by paulh »

All I can suggest is you have to have the backend IP settings on both master and slave set up properly for it to work.

Peter changed how it's supposed to work now so hopefully he see this and will reply but from what I remember there is a check box that should be checked on the master but unchecked on the slave. You have to have both machines using IP addresses that are on the same network and are not 127.0.0.1. I think the hostname of at least the master should resolve to the IP address of that machine at least for some things to work properly. Easiest way I find is to just edit /etc/hosts assuming you are using static IP addresses.
hedgehog52
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Re: Storage Groups - don't understand documentation

Post by hedgehog52 »

paulh,

At one point the only thing that was wrong was that the HDPVR showed an error. But, as I've continued to try different things, I think I strayed just a bit too far, somewhere, and now it's all borked. I'll just have to try again when I feel a bit better.
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