Balance immediately settings with frequent temp files

[JasonC]

I was watching DrivePool operations recently and I suspect the aggressive balance immediately settings are actually probably hurting overall performance of file operations that frequently happen for me. Specifically, merge/decode of multi-part files. I have an SSD in the pool with the SSD Optimizer, and I had thought there was a little delay before the balancer tried moving files off, but watching the operations, it looks like this actually happens much quicker than I thought. The net result being that I think temp files are getting pushed to spindle disks and decode ops are happening from there instead of on SSD. I'm going to enable the "not more often" settings and just swag a value, and see if that improves performance.

I'm more looking for commentary on if my reasoning is correct with my observations of what I'm seeing in the DrivePool UI.  It would explain why some of those things always seemed to take a little longer then I thought they should against an SSD(since they weren't against SSD!).

Thanks!

 

 

[JasonC]

So the balance setting changes does seem to do what I want, so my observations appear correct.

Related question, with regard to the balance settings and migration from SSD with the SSD Optimizer. I'm using the balance "not more often" setting with a 10 minute interval.  2 questions related to that:

1) does that mean the balancer kicks off every 10 minutes regardless, or does it check if other parameters are set, and run based on those (for instance, if a ratio value is set)

2) Is the balancer going to be very basic and just move everything at that time from my SSD, or is it based on the age of the items being moved? Ideally, I'd like it to be age based, the idea being that files that are recent in use(so say, they last couple of minutes if I am running it every 10) I don't want to move yet, since they are more likely to be waiting for additional processing. I can set the interval higher, but that's a fairly crude approach and really doesn't get me what I want, just reduces the frequency that it would move files that are recent in-use/likely to be used again soon.

Thanks!

 

[Christopher (Drashna)]

3 hours ago, JasonC said:

1) does that mean the balancer kicks off every 10 minutes regardless, or does it check if other parameters are set, and run based on those (for instance, if a ratio value is set)

Yes, the software will check every 10 minutes to see if the ratio (or amount) dictates that a balancing pass is necessary. 

Unless it's already running a task (balancing, duplication, etc0. 

3 hours ago, JasonC said:

2) Is the balancer going to be very basic and just move everything at that time from my SSD, or is it based on the age of the items being moved? Ideally, I'd like it to be age based, the idea being that files that are recent in use(so say, they last couple of minutes if I am running it every 10) I don't want to move yet, since they are more likely to be waiting for additional processing. I can set the interval higher, but that's a fairly crude approach and really doesn't get me what I want, just reduces the frequency that it would move files that are recent in-use/likely to be used again soon.

It's basic.  So yes, "everything" gets moved. 

 

As for the age based, yeah, I'd like that as well.  the problem is that it would require an overhaul to the balancing engine to accomplish this.  So not a minor code change.   It's something that I'd personally like done, and there is a feature request for is.  But for now ...

 

 

Also, it should be noted that "in use" (eg copying) files don't get balanced until the next pass.