SSD usage with more than one SSD as cache

[propergol 10]

I am not 100% sure of that but with 3 SSDs as cache (since I have some folder duplicated x3) when I write to the pool into a folder without duplication then this is always the same SSD that is used.

If I am correct then it would be better if write could be randomly done on one of the 3 SSD and not always the same one.

[Christopher (Drashna) 631]

That may be the case.  Specifically, the drive with the most available free space is selected. It may be that this one drive has slightly more free space than the others. 

 

If that's not the case, then it may be just how it's selected. And if that's the case, let us know.

[propergol 10]

I have recreated partition on the 3 SSDs so they have now the exact same space avaible.

I have made other write tests and it realy looks like the same SSD is always used when duplication is x1 so no duplication.

 

An other thing I did noticed is that when writting to a x3 folder, so basicaly to the 3 SSDs at the same time, then in main DrivePool disk perfomance windows, only one SSD write is shown. We should normaly have 3 bars since 3 SSDs are being written.

[Umfriend 106]

But do you see the file appearing on all three SSDs?

[propergol 10]

But do you see the file appearing on all three SSDs?

I guess yes because the bars showing SSDs space usage reports used space that is emptied as soon as the data have been written to pool's HDs.

[Christopher (Drashna) 631]

I have recreated partition on the 3 SSDs so they have now the exact same space avaible.

I have made other write tests and it realy looks like the same SSD is always used when duplication is x1 so no duplication.

 

An other thing I did noticed is that when writting to a x3 folder, so basicaly to the 3 SSDs at the same time, then in main DrivePool disk perfomance windows, only one SSD write is shown. We should normaly have 3 bars since 3 SSDs are being written.

I've actually noticed the same. So there is definitely a bug there. 

 

However, this is a performance UI bug.  When I've seen this, I've manually confirmed that all copies are created properly. So it's definitely a UI bug.

 

Flagged for Alex (the developer).

https://stablebit.com/Admin/IssueAnalysis/20843

 

However, could you enable file system logging, reproduce it and upload the logs? 

http://wiki.covecube.com/StableBit_DrivePool_2.x_Log_Collection

[propergol 10]

I am uploading the logs.

Here is what I did :

- started DrivePool log

- copied 18GB movie to a x1 DrivePool folder

- waited for SSD cache to write it to HD

- copied the same movie from the same source to a x3 DrivePool folder

- waited for SSDs cache to write it to HDs witch took longer since SSDs are emptied one by one.

 

I hope it could help.

 

 

EDIT : uploading done.

[Christopher (Drashna) 631]

Thanks for grabbing the logs!

 

I've flagged them for Alex (the Developer), and he'll get to them soon (hopefully).