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SSD & VM : Cache, Pool or Unassigned device ?

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I have a UNRAID server with 10 mechanical drives (and different "quality", replace the old ones one by one).

As noticed, the write on the array rarely exceed 80Mb/s, so my 1Gb/s network is never the bottleneck.


Right now, my VM is inside the array and i would like to move it to a spare SSD i have.


I don't really know what is the best pratice :

- Unassigned device with rsync backuping it every night on the array

- Cache pool only for VMs (did it move everynight inside the array ?)

- The new "pool" feature i don't really fully understand yet ?


I don't want to lose the array protection, even if it is only every 24h, like daily backup without shuting down the VM. Thanks.


Thanks !

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If you want the VM's vdisk to be parity protected, then you leave it on the array, and suffer through the massive performance hit (or put it onto the SSD and look at the VM backup plugin)


Cache Pools in a nut shell are what you should be using.  Previously, people used Unassigned Devices to mount a drive that was permanently attached to the server to use it for things like VM storage.  The Cache Pool feature supplants this and is a ton easier to handle / manage.

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Hello Squid and thanks for the quick answer.


1/ SSD : i didn't know about VM backup plugin, and i guess it can do the job.


2/ Cache Pool : I understand that it is the best choice. Only interrogation i have left is about Mover.

From what i read, it is said that the mover do not "move" the file in use, and i guess the vdisk will always be in use.

So, it seems good in you have 2 SSD in cache pool with protection, but not so good if you use only one SSD, so without protection.


Or i use one SSD in Cache Pool along side with VM backup plugin ?

That seems to be the good solution ?


Thanks !

Edited by Keichi
Post before finish the writing ^^'
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  • trurl unlocked this topic
  • 5 weeks later...

New to unraid here.


I just installed plex media server, and also created a new ssd pool to put the plex appdata in.


how do I transfer the plex appdata to this ssd pool,without losing all my plex history and metadata?

Also how do I backup the plex appdata on a regular basis?


much thanks for your help



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  • 1 year later...

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