cache ssd != VM ssd

Hi all, looking to get my system set up a little better now that everything is running well, shares are all working like I want, and my vpn is at least operational.

I currently have three VMs running off my 250GB SSD that's currently assigned as a cache drive, and all my share saves are written directly to spinning disks. I have a spare 120GB SSD that I want to use as an actual cache drive and have my VMs running on a separate SSD that is not written to as a cache drive.

I get how to set up the cache drive and use the mover and all that. I remember reading something about mounting drives outside the array... but don't know if this applies here or is doable and still have the VMs accessible. I also don't think that setting up a cache pool is the right approach here.. ?

Can someone please point me in the right direction?

Thanks

Tiwing

Hi all, looking to get my system set up a little better now that everything is running well, shares are all working like I want, and my vpn is at least operational.

 

I currently have three VMs running off my 250GB SSD that's currently assigned as a cache drive, and all my share saves are written directly to spinning disks. I have a spare 120GB SSD that I want to use as an actual cache drive and have my VMs running on a separate SSD that is not written to as a cache drive.

 

I get how to set up the cache drive and use the mover and all that. I remember reading something about mounting drives outside the array... but don't know if this applies here or is doable and still have the VMs accessible. I also don't think that setting up a cache pool is the right approach here.. ?

 

Can someone please point me in the right direction?

 

Thanks

Tiwing

Some of this comes down to preference. In the past I ran my VM's off an SSD running "Outside of unRAID" via the Unassigned Devices Plugin:

https://lime-technology.com/forum/index.php?topic=45807.0

However, after some discussion I didn't see the need for it anymore:

http://lime-technology.com/forum/index.php?topic=46811.0

In short, I felt that pooling my drives to be managed in the "Supported" way was better for me. In addition I was able to take advantage of redundancy for my Docker, VM and Cache files which was unavailable (and is currently not on the roadmap) via the Unassigned Devices Plugin.

There is a middle ground here where you can still use the Cache device but not in BTRFS RAID-1 but BTRFS RAID-0. See here for recent discussion on how to do this:

http://lime-technology.com/forum/index.php?topic=47698.msg457160#msg457160

Remember, the "Supported" method is to run these from a "Cache Only" (and as such it is ignored by the mover) share on the Cache drive.

Some of this comes down to preference. In the past I ran my VM's off an SSD running "Outside of unRAID" via the Unassigned Devices Plugin:

 

https://lime-technology.com/forum/index.php?topic=45807.0

 

However, after some discussion I didn't see the need for it anymore:

 

http://lime-technology.com/forum/index.php?topic=46811.0

 

In short, I felt that pooling my drives to be managed in the "Supported" way was better for me. In addition I was able to take advantage of redundancy for my Docker, VM and Cache files which was unavailable (and is currently not on the roadmap) via the Unassigned Devices Plugin.

 

There is a middle ground here where you can still use the Cache device but not in BTRFS RAID-1 but BTRFS RAID-0. See here for recent discussion on how to do this:

 

http://lime-technology.com/forum/index.php?topic=47698.msg457160#msg457160

 

Remember, the "Supported" method is to run these from a "Cache Only" (and as such it is ignored by the mover) share on the Cache drive.

Awesome discussion (your second link), thank you so much for sharing that. I'm not sure why I was under the impression that the cache pool could only be up to 2 disks, only same size, and the only benefit to multiple cache disks was "automatic raid1... But it seems that you can create a cache pool of multiple SSDs and span them just like the unraid array itself - so 2x 250GB SSDs could be set up to be 500GB, or they could be mirrored or striped if you wanted to (why you'd raid 0 two SSDs I'm not sure but holy crap it would be fast! )

Clearly I have more reading to do. The good thing is that I have my VMs already all running from a cache only share so it looks like I'm half way there.

Thank you. I'm sure I'll be back with a few more questions / comments along the way.

Cheers