Privileging performance over available space

[Odeen]

Hi,

referring to this post and how DrivePool acts with different size drives, I found myself copy/pasting a file and DrivePool used the same drive for the entire operation (as the source and the destination).
This resulted in a really poor performance (see attachments; just ignore drive "E:", there are some rules that exclude it from the general operations).

Same thing extracting some .rar files.

Is there a way to make DP privilege performance over "available space" rules?
I mean, if there is available space on the other drives it can use the other drives instead of the "source" one.

Thanks

[Christopher (Drashna)]

From the UI, it looks like the file is being moved from the N:\ drive to another location on the N:\ drive, but isn't using "smart move".  

In this case, this fould be more normal, as the file system is both reading and writing to/from the drive.  That means that the I/O is split between the two.  In a best case scenario, this would halve the speeds, meaning you're really seeing closer to 70MB/s speeds here.  But in reality, you may see worse than half, because of overhead (such as head actuation).  So you may may have been getting 80-90MB/s or faster from the drive normally. 

 

As for this sort of prioritization, it's very hard to do, as determining this "on the fly" is complex and ... "expensive" (in terms of system resources). 

However, we do have the SSD Optimizer, which would help with this immensely.  It's designed to create a write cache for new files.  New files (like this) would be written to the "SSD" drive first, and then later balanced off to the other disks.  This would split up the I/O load, and put the new files on the much faster drive, potentially boosting speeds.