May 6, 201511 yr v6b15 - completely blank cache drives and data drives (d'oh). Enabled Docker but the tab doesn't come up in the webUI. Er....
May 6, 201511 yr Did you give it a size and path for the docker img? Path must be on a disk, not a user share. I have mine at /mnt/cache/docker.img. You can put it at the top level of cache since mover doesn't touch files only folders at the top level. You must actually type the size into the box, the placeholder is just an example.
May 6, 201511 yr Oh I didn't type a size. That's not obvious BTW limetech! You can turn on the help function, it gives more details about what to do ...
May 6, 201511 yr Author Actually my issue was that I hadn't made the directory on the cache drive I'd configured. I assumed it would for me, its now sorted.
May 7, 201511 yr Actually my issue was that I hadn't made the directory on the cache drive I'd configured. I assumed it would for me, its now sorted. Hope you remembered to make it a cache-only share!
May 7, 201511 yr Actually my issue was that I hadn't made the directory on the cache drive I'd configured. I assumed it would for me, its now sorted. Probably should allow folks to create directories. Maybe we'll add that feature in later. Oh I didn't type a size. That's not obvious BTW limetech! As far as not typing in a size, what's not obvious? Is the text box that says "size" and the help text not obvious enough? Maybe we should just implement a javascript handler for this that says, "one of these form fields isn't filled out, I'll give you a hint which...it's the empty one." ;-)
May 7, 201511 yr Author Yes. Validation would have prevented this! I actually hadn't noted that the example text wasn't valid for at least 5 mins. All rather embarrassing.
May 7, 201511 yr Author Next dumb Q... Docker 'images' is as unRAID has it, an odd concept to me. I need to specify a size limit? Why?
May 7, 201511 yr Next dumb Q... Docker 'images' is as unRAID has it, an odd concept to me. I need to specify a size limit? Why? As I understand it, the docker app creates a virrtual btrfs img to the size you specify. I can't say why that is the implementation.
May 7, 201511 yr Next dumb Q... Docker 'images' is as unRAID has it, an odd concept to me. I need to specify a size limit? Why? As I understand it, the docker app creates a virrtual btrfs img to the size you specify. I can't say why that is the implementation. I think btrfs has some ability to allow dockers to share code storage. That whole copy-on-write thing. Or something.
May 7, 201511 yr Next dumb Q... Docker 'images' is as unRAID has it, an odd concept to me. I need to specify a size limit? Why? As I understand it, the docker app creates a virrtual btrfs img to the size you specify. I can't say why that is the implementation. Docker requires BTRFS CoW and snapshot to have good performance. To not enforce users to format their drives with BTRFS, Tom decided that a loop device mount would be better to isolate Docker needs from the rest of the array. Some info on loop device: http://en.wikipedia.org/wiki/Loop_device
May 7, 201511 yr Next dumb Q... Docker 'images' is as unRAID has it, an odd concept to me. I need to specify a size limit? Why? As I understand it, the docker app creates a virrtual btrfs img to the size you specify. I can't say why that is the implementation. Docker requires BTRFS CoW and snapshot to have good performance. To not enforce users to format their drives with BTRFS, Tom decided that a loop device mount would be better to isolate Docker needs from the rest of the array. Some info on loop device: http://en.wikipedia.org/wiki/Loop_device I dont know about that. I'm not seeing anything drastically horrible when I run Docker under Boot2Win on my Windows OS. Unless the virtual linux vm itself is using BTRFS. Then again my WinOS is on SSD. Maybe performance is just a dog on spinners. Since LT began on docker, they have had at least 4 updates to it, from 1.2 to 1.6. So maybe things improved since then on non BTRFs filesystems.
May 7, 201511 yr And it can easily expand the image if you need to. Just stop docker, put in a larger size, restart. You can't shrink it easily though. But the best thing is the xml template storage. You can delete the image entirely, create a new one, and then recreate all your dockers with the same settings in under a minute
May 7, 201511 yr Author Ok - it seems an odd decision but the technical reasons make sense(ish). I wish the size limit were optional as I really don't want to allocate several GB to a simple NGINX container. I just simply want all the Docker stuff to live on my cache drive (which is an SSD). I don't care (or want to care) about the size of each image.
May 7, 201511 yr But the best thing is the xml template storage. You can delete the image entirely, create a new one, and then recreate all your dockers with the same settings in under a minute Yes, that is nice but has nothing to do with the BTRFS docker image usage.
May 7, 201511 yr Ok - it seems an odd decision but the technical reasons make sense(ish). I wish the size limit were optional as I really don't want to allocate several GB to a simple NGINX container. I just simply want all the Docker stuff to live on my cache drive (which is an SSD). I don't care (or want to care) about the size of each image. All dockers will install in this storage. I have mine set to 20GB. I have 10 dockers installed and it is using just over 10GB currently. Note that this will not include docker application data, such as the Plex library. Each docker's application data will reside in unRAID storage somewhere. Most people make a cache-only share for use by all their dockers application data.
May 7, 201511 yr Ok - it seems an odd decision but the technical reasons make sense(ish). I wish the size limit were optional as I really don't want to allocate several GB to a simple NGINX container. I just simply want all the Docker stuff to live on my cache drive (which is an SSD). I don't care (or want to care) about the size of each image. it's the total storage size allocated for all your dockers combined, not for each individual docker.
May 7, 201511 yr Author Aha I see. And the fact that it's CoW means that the space isn't used until it's used. Right, cleared that one up I think. Thanks guys.
May 7, 201511 yr But the best thing is the xml template storage. You can delete the image entirely, create a new one, and then recreate all your dockers with the same settings in under a minute Yes, that is nice but has nothing to do with the BTRFS docker image usage. Well I wasn't really responding to you, your comment must have been posted while I was drafting mine My second statement was referring to my first. You can move around the image, modify the size, etc. And even if you accidentally mess it up up or delete it, you can always recreate it without having to remember the original docker run command and specific parameters
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