It would be nice if there was a way to create multiple parity groups, so that you can have one for your data disks (think capacity) and another for active disks (like VM's, docker apps, etc)

 

For example I would have one of spinning disks for my data and one of SSD's for my apps, because I like having the mirror of my apps in case of disk loss.

your apps/dockers/vm images on cache are mirrored if you use 2 disks.

your apps/dockers/vm images on cache are mirrored if you use 2 disks.

 

Not everyone wants VMs on SSDs or mixed into the cache pool. Using Unassigned Devices is nice, but if I'd like to use a HDD based raid 0 or JBOD pool, unless I do it in hardware I'm out of luck.

 

 

It would be nice if there was a way to create multiple parity groups, so that you can have one for your data disks (think capacity) and another for active disks (like VM's, docker apps, etc)

 

For example I would have one of spinning disks for my data and one of SSD's for my apps, because I like having the mirror of my apps in case of disk loss.

 

This has been asked for a lot, based on my reading of the forums. If they were to do another unraid like parity backed pool the write speeds would be abysmal.

 

That said, with UR6s bold expansion into KVM territory it does seem like some attention should be given to separating the main pool out from an apps pool. That said, I'm not sure what that would look like even if they do decide to address it. Unassigned devices plugin is nice, but it should really be core feature. 

your apps/dockers/vm images on cache are mirrored if you use 2 disks.

 

Not everyone wants VMs on SSDs or mixed into the cache pool. Using Unassigned Devices is nice, but if I'd like to use a HDD based raid 0 or JBOD pool, unless I do it in hardware I'm out of luck.

 

 

 

which is why i asked for : https://lime-technology.com/forum/index.php?topic=56612.0

I can't imagine there isn't a capability in linux to do multiple software raid setups at once on a system. That just sounds like crazy talk.

I can't imagine there isn't a capability in linux to do multiple software raid setups at once on a system. That just sounds like crazy talk.

Sure there is. Unraid isn't generic linux software raid, the raid part is custom written, so multiple software raids would need some rewriting of unraid. Not a simple undertaking, considering the rewrite would be mucking about with what makes unraid different. If you want to set up multiple software raid pools in a generic linux installation, it is very simple.

On 2/17/2017 at 8:58 PM, jonathanm said:

On 2/17/2017 at 4:40 PM, eagle470 said:

I can't imagine there isn't a capability in linux to do multiple software raid setups at once on a system. That just sounds like crazy talk.

 

Sure there is. Unraid isn't generic linux software raid, the raid part is custom written, so multiple software raids would need some rewriting of unraid. Not a simple undertaking, considering the rewrite would be mucking about with what makes unraid different. If you want to set up multiple software raid pools in a generic linux installation, it is very simple.

 

 

The point I was trying to make was that the ability to make multiple raid goups using software raid already exists in Linux, so if Unraid leverages that the POSSIBILITY has to exist, even if its a feature in 7.0 or something.

 

See below for WHY I'm requesting this.

Edited February 22, 20179 yr by eagle470

Having the ability to configure multiple pools, with the same options available, no/single/double parity, would allow complete flexibility. It would also allow for the removal of the BTRFS for cache drives, as the cache could be removed, just create an SSL pool.

 

In addition, I'd like to be able to tag the pools with a hierarchy, fast/general/slow etc. this would then replace the cache mover script with something more advanced.

 

If Unraid's parity performance is poor (and is why BTRFS is used??), maybe that should be addressed separately?

On 2/22/2017 at 3:09 PM, eagle470 said:

 

 

The point I was trying to make was that the ability to make multiple raid goups using software raid already exists in Linux, so if Unraid leverages that the POSSIBILITY has to exist, even if its a feature in 7.0 or something.

 

See below for WHY I'm requesting this.

 

take the ssd out of your array. your write speed is limited by the fastest (slow) spinning disk and iirc the ssd is not getting trimmed.

On 3/20/2017 at 6:30 AM, 1812 said:

 

take the ssd out of your array. your write speed is limited by the fastest (slow) spinning disk and iirc the ssd is not getting trimmed.

So how would you recommend I accomplish my goal? I'm not running the SSD for speed, but for power savings (granted its about 5 watts vs 20, but still.) 

2 hours ago, eagle470 said:

So how would you recommend I accomplish my goal? I'm not running the SSD for speed, but for power savings (granted its about 5 watts vs 20, but still.) 

 

 

Add another ssd of the same size and use them as cache, then one disk of data is mirrored. 

 

or

 

use a single ssd as cache and back up the ssd to the array nightly if you're worried about data loss.

 

PLUS

 

whenever you write to your ssd in the array, you also spin up your parity drive. so not just using your 5 watts, but also the 20ish for your parity drive. 

 

 

and after you do either of the above, go into the multiple cache pool thread I created (linked above) and voice your support for it there.

 

 

Ended up building a parity pool and resetting the data drives to pull the SSD out and moved everything to cache.