Are the operations / IO / IOPS for Drivepool slower than a normal disk?

[zurich]

In Windows when deleting something like 100,000 files, it's quick and completes in a few seconds. This is a high-level delete operation.

IO operations with Drivepool all take a much longer time than Windows. Things such as:

1. In explorer: Right-click folder > properties (to view number of files, folders, size)
   1. OK, I'm not sure this one is drastically slower (if at all).
2. Discovery takes a long time for a delete. Like #1 above.
3. A delete operation take a long time for a large number of files. I'm talking like 50-150 IOPS, which makes me think this is related to disk IOPS.

Can these operations be dependent on any settings for my pool, or is this just part of the territory for what Drivepool does beneath the surface? Correct if I'm wrong: operations in Drivepool seem to be limited by the IOPS of the disk(s) in question.

[Christopher (Drashna)]

For the most part, StableBit DrivePool is passing the IO directly to the underlying disks.  

However, if you have an antivirus program, it can cause some issues here, as it intercepts all of these commands. And with DrivePool, it may/will intercept them twice.  So if the virus scanner has issues with that, it could cause a performance hit. 

 

If you enable the "bypass file system filters" option (in Manage Drive -> Performance), this may improve performance. 
Additionally, if you have a very low end CPU, it may affect this, as listed and opening files is actually cuP intensive. 

 

Furthermore, if the data has done a lot of balancing, then there may be a lot of empty folders on each of the drives in the pool, and that may slow down the deletion process, as reported.  

[zurich]

Interesting. I'll try it again, but it definitely seems slower. But even deleting 50-100 items per second isn't a huge deal.

[Christopher (Drashna)]

It may be slower, yeah. 

Oh... ans if you're deleting directories, there may be some additional overhead there, as we have to do some "special stuff" to handle this correctly. We've ran into odd issues with the entire deletion routine. So, there is that, as well. 

If you want, enable file system logging and reproduce.  
http://wiki.covecube.com/StableBit_DrivePool_2.x_Log_Collection