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cache ONLY VM/domains copy to array using mover

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As I spent 4 days understanding/googling forums about mover/cache functionality as a last resort I ask here in forums  maybe simple question:


Is it possible to have:


VM/domains data to RUN from cache ONLY and in case of running Mover - let it COPY new/changed files to array - I mean copy, not MOVE.


I already experimented with all cache options and they are absolutely not built to handle such situation. Or maybe not cache option but MOVER. We cant control Mover behaviour. As I see it its only possible with copy scrips or manual copying. Running VMs is maybe better to have it all on Unassigned devices which are unaffected by mover. First I thought that mover /using cache Yes or manual invoking/ will compare files on cache and array and then will copy newer files from cache to slow array but its not.


I have all cold data on array of 2x4TB + 1x4TB parity, BRTFS

Cache is pool of 2x 1TB Samsung 860 SSD in RAID0 /on purpose/


Running 4x VMs with passthru NICs. I do lot of VM testing /coming from VMware Vsphere/ so need to have fast primary storage and reliable back up to big array nightly.


Or should I forget Mover for good and let copy scripts take over ?


Thanks for all constructive hints/solutions.


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Mover doesn't do backups or make copies. It just moves.



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My solution to VM backups was have the "domains" share as "Cache Only" and a share called "domains_backup" set to "No Cache".


Then I just shut-down VM's after any major changes and copy the VM vdisks from "domains" to "domains_backup" then start the VM back up again.  I just make a new folder with today's date then copy the Folder for the domain I want over.  I'll also copy over libvirt.img after changes to the dated folder as well just in case.


I'm not sure how scripts would work with shutting down and starting up VMs, but if you can figure that out, then copying files between shares like I have set up would probably be your best bet in my mind.

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Thank you very much, I see manual copy as best option now as using autovmbackup script and some other scripts often fail even with VM powered off. 


Backing up 4x 100GB VMs with speed 50-75MB is really test of someones nerves, lol. Used 10GB NICs in VMware and Synology/Qnap as targets before and it was like 300-500 MB/s to old spinning HDDs in RAID5.


I even used Unassigned HDD as a target, used turbo write, shut down parity and cant get more than 75MB/s when backing up VMs from cache SSD in RAID0 to array or unassigned brtfs HDD.


Recalculating parity or precleaning HDDs is 180 MB/s - real/advertised speed of single HDD.


I understand parity thing - just its really slow for my use. Maybe all SSD array /TRIM thing resolved/ could be my solution in the future...


One more idea: use brtfs SSD pool in Unassigned devices as backup target ? but thats insane price ratio wise.




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