Feature request: Duplicate-only drives (i.e. backup drives)

[mate]

I think it would be great if in DrivePool it would be possible to configure some drives in the pool to only contain data that is duplicated on at least one other drive. That is, non-duplicated data would never be stored on that particular drive.

 

Use case at hand: I'm replacing a couple of fully functional 1.5 TB drives for 3 TB ones, because after 5 years their Load Cycle Count is off the charts according to StableBit Scanner. While at the moment they show no symptoms of deterioration, it would seem like they could still be part of the pool for duplication (and thus freeing up more space on the 3 TBs), but since they could in theory die at any minute, I do not want any data to be kept only on those drives (including data that I would entrust a single of the 3 TB ones).

[Christopher (Drashna)]

Yup, this has been requested.

 

Specifically "duplication groups" so you can specify that one set of disks gets a copy of the files, and another set gets the other. 

 

 

 

However, one option here is to open the Balancer settings, and the "Balancers" tab.  

From there, you can set the "StableBit Scanner" balancer to evacuate unduplicated (and optionally, duplicated) data from a disk with SMART errors (this is turned off by default, because things like the temperature can trigger this). 

 

Optionally, you can use the "Disk Usage Limiter" balancer to only place duplicated files on the drive, by unchecking the "Unduplicated" data option for the disk in question.

[cryodream]

Yes Yes Yes. Drive groups or duplication groups. This is a must, imho.

[Umfriend]

I still like the name "Strings" for groups of HDDs. It would also be nice if one could assign one or more HDDs as hot-additions. E.g., you could have 2 strings of 3 x 4TB HDDs and have one 4TB HDD spare to take over once Scanner wants to vacate a damaged HDD.

[RedPark18]

To add to this or to say how I'd like to see it used for a situation I'm having is as follows:

 

Drive Pool (A:) contains all my media I access with Plex, all files are duplicated.

 

I would like to buy the cheaper HDD's that are for Archiving, so if I could add it to the pool but only have duplicated (copied) files be on it and not the originals that Plex would be accessing then that would be the best option.

 

Now I may be preventing this because I added balancers that are moving files around to keep all drives about equal in free space %. But I would like for this to still be occurring so that I'm not manually trying to keep the drives even, but since I don't plan to read from these Archive drives I'd be fine to let them fill up a lot more than the others.

 

Is this already an option I'm unaware of? Looking to buy some of these Archive HDD's so that I can back up my entire pool.

[Christopher (Drashna)]

Well, the "Drive Usage Limiter" balancer allows you to specify that if a drive will host duplicated data or unduplicated data.  

 

However, I'm guessing what you're referring to is more of "duplication grouping". This is something that we do plan on adding.