Drivepool with primocache

[lyzanxia]

I was wondering if it was possible to use primocache on drivepool?

Have lots of ram which could be used to function as a landing area to speed up my archive disks.

 

Another question is: I have a large raid0 ssd array, is it possible to use driveletters on this array to be used as ssd landing disks? Or does the ssd landing disk have to be a physical drive to be used with the ssd landing option in drivepool?

 

Thanks 

[Christopher (Drashna)]

I'm not sure that it would work with StableBit DrivePool.

 

Worst case, it may ... well BSOD the system. Barring that, then you may not be able to use it with the Pool volume (I'm not sure, and will test this later).

But if that is the case, you *may* be able to use it with the pooled drives.

 

As for the RAID array, this depends on how you've created the array. As long as it's not using "Dynamic Disks" then you should be able to use the drives as a landing disk.

Check out the "SSD Optimizer" balancer.

https://stablebit.com/DrivePool/Plugins

[lyzanxia]

Did you have a chance to try primocache? Would try it myself, but am not sure if it would have strange effects on the drivepool mechanism.

 

Seems as the ssd plugin, needs physical ssd disks..I cannot choose driveletters as ssd landing destinations.

[Christopher (Drashna)]

Sorry, yes I did.

 

It doesn't seem to do anything with the Pool drive. 

However it does seem to work for the physical drives in the system.

 

 

As for the SSD optimzier, you need to add the drive to the pool first. Then it should allow you to choose the drive as an "SSD" drive. And in fact, it doesn't need to be an SSD.

[lyzanxia]

Thanks Christopher for testing.

 

Would you say it would be beneficial to use primocache on the physical drives?

Or better said, would drivepool work properly if I would accelerate the underlying drives using the ramcache?

 

Regards

[Christopher (Drashna)]

You are very welcome.

 

 

And to be honest, I'm not sure how much benefit you'd get, depending on your usage. 

If you have good, higher performance drives, you'll see around 100MB/s read speed. 

Considering that over the network, the max theoretical speed over gigabit is 125MB/s, and that's not counting overhead or cable quality, etc....

 

 

Additionally, if you are using duplication, we do "read striping" which may increase the performance of the access, based on the disks in the system. (we'll use the faster drive, or if both are similar speeds, we'll cache the reads to memory). 

 

 

Also, since we use the normal methods for accessing the data on the drive, using it to boost the speeds on the disks in the pool should add the same sort of acceleration/boost.

[Christopher (Drashna)]

Also, because I think I may have misunderstood/skimmed....

 

THe SSD Optimizer (and DrivePool in general) requires any disk that is to be added to the pool to be recognized by VDS (the virtual disk service). If it's not, then it's an emulated drive, and won't work.

[lyzanxia]

I'm now trying primocache.

I would rather have used the ssd optimizer plugin, but I was unable to use it, since it will only use disks as ssd cache.

It won't allow a partition to use as landing disk (which primocache could).

 

I have now made a partition on my ssd raid0 array which is now in use for this purpose.

 

Maybe Alex can find a way to allow this?

[Christopher (Drashna)]

I'm assuming you mean with the ramdisk option. 

If it's not showing up as a physical disk, and as an option to add to the pool, then no, it wouldn't be usable.

 

Also, depending on how the software handles the disk, it may cause issues. Specifically, if the contents don't remain, then every time the system reboots, you'll have a missing disk, and will have to set it back up. Obviously, this is not desirable behavior.