Cache Only/Standalone Mode


Dimtar

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Sorry if this has been posted before but I wanted to put forward the idea of using unRaid without the array.

unRaid has very strong docker and VM support now. I for one can see myself setting up a machine that has say one SSD installed and its just simply a docker/VM machine only. Storage could be added later if needed of course but the ability to start the server with only a cache drive would be cool in my opinion.

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1 hour ago, Dimtar said:

Last I checked SSDs couldn't be array drives?

UnRAID will not stop you from assigning SSDs as Array drives.   They are not officially supported because of potential issues with the way they might interact with Trim potentially invalidating Parity (depending on how a particular model of SSD handles Trim operations).   If you are running without a Parity disk this is not relevant.

 

There have also been tests done by existing unRAID users with SSD based arrays and they seem to work fine for the SSD models they were testing at the time.  

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  • 8 months later...

I hate to resurrect a somewhat old thread, but it's the only one I could find.

 

I would *LOVE* to have the ability to create a cache drive only unRAID rig just to run docker/vm on a multi disk BTRFS cache pool, without having to create/waste data disks.  I'm using a 30 drive array now, and using 4 SSD drives as cache only, with only the docker/vm images on the cache pool.  I'd move the 4 SSD drives in a heartbeat to a new rig running a cache only setup.

 

 

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unRAID requires at least ONE array disk (parity disk is optional). It needs to start the array to make the cache pool available.

 

It has been debated here, but removing the array dependency is a hard thing to do in the current design, not to mention the whole licensing concept based upon it.

 

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6 hours ago, bonienl said:

unRAID requires at least ONE array disk (parity disk is optional). It needs to start the array to make the cache pool available.

 

It has been debated here, but removing the array dependency is a hard thing to do in the current design, not to mention the whole licensing concept based upon it.

 

 

yea, I know all that.  And after I wrote that I thought "Well, that's basically not unRAID anymore, it's more like Tom's Docker Manager" :)

 

Thanks tho.

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  • 1 year later...

Will this still somehow be considered in the future ? I assume more ppl are using unraid for docker/vm only.

 

So now the only option (when I want to use ssd with trim support and some kind of redundancy) is to use old usb drive assigned in the array

and then running ssd cache pool in raid1 ?

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4 hours ago, perrycox said:

Will this still somehow be considered in the future ? I assume more ppl are using unraid for docker/vm only.

 

So now the only option (when I want to use ssd with trim support and some kind of redundancy) is to use old usb drive assigned in the array

and then running ssd cache pool in raid1 ?

I very much doubt that this restriction will be lifted (but I could be wrong).   Since you could just use a small flash drive to satisfy the requirement of having at least one array drive it is not much of a hardship.

 

what we DO know is coming in the next Unraid release is multiple cache pools which will allow those running primarily docker/VMs to tune their use of caches to better suit their workload.

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  • 4 weeks later...
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5 hours ago, Pascal51882 said:

Is it save to run a single SSD Array without parity? Heard of problems with trim in the Array. Currently I am using a spare USB as Array and my SSD as Cache for all docker/vms. The USB seems like a big point of failure for me even it is 100% empty.

If the USB drive is empty and is not getting any reads or writes then I do not see how it is a point of failure.    In the worst case it would just be a case of replacing it with another empty USB.

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