SSD Optimizer question

[WBadminUser]

I was going to start using this however i seem to remember when i played with it the a while back. That if i ran the SSD out of space by performing a large copy it would start erroring out as opposed to putting the data on the other disks. The way i would want it to be handled is to fill the SSD then start filling the other disks.

Please advise on the way to avoid this.

[Christopher (Drashna)]

It really depends on the size of the "SSD" drives, and the files are you are copying over. And HOW you are copying them over.

 

The simplest solution is to ... well, throw more SSD or larger drives at the problem. You can find "White Label" 600GB 10K RPM drives for relatively cheap. It would be very useful for this, though not as fast as SSDs.

 

Also, what size are the files are you plan on copying?

 

And is this being done over the network? If it is, you may not need to bother with the SSD Optimizer balancer. The reason for this is that depending on the drives, you may see 80-100MB/s speed to the drives. If you're moving files over the network, gigabit's maximum theoretical (raw) speed is 125MB/s, and you're more likely to see ~100MB/s.

That means if you're copying files over the network primarily, you may not be seeing any significant gain in performance by using the SSD optimizer.

 

However, if you're using the Pool locally, then you will definitely see an advantage to doing so.

Additionally, allowing it to write to slower disks sort of defeats the purpose here (being to put the files on the fast disk, and then move them off to the slower disks).

[WBadminUser]

These are all good things to keep in mind. I will probably pass on the SSDs for these "archive" pools after everything you pointed out.

[Christopher (Drashna)]

Yeah, the SSD optimizer is for a fairly specific use case. And there are definitely some caveats. But in some cases, it can be very useful.