XFR off pooled drive painfully slow

[Kevin]

I'm trying to copy about 3TB of data off a pooled volume onto a USB 3.0 external drive, sadly this process is painfully slow. We're talking USB 2.0 speeds ~30-40 15-25MBps. Pooled disks are all SATA 6 so that can't be the issue. Not exactly where to look at this point.

 

Any help?

 

Thanks

Kevin

[Christopher (Drashna)]

Unfortunately, this isn't always a straight forward issue.

 

Do you know what model of HDD is in the USB external drive?

If this is a smaller drive (physically, not capacity), it may be a "laptop" drive, and these generally do turn at a lower RPM, which translates into lower performance.

 

Do you have any antivirus, backup or disk tools installed on the system? 

Could you run this:  http://wiki.covecube.com/StableBit_DrivePool_Q2159701

These software types commonly use "file system filters". Filters are basically drivers that sit inbetween the file system and the actual drive access, and ... well, filter the connection. These can cause issues and performance hits, if the filter isn't properly designed, or can interact negatively with other filters/software.

 

If you copy files from one of the pooled drives to the USB drive, do you see a difference in performance?

If so, could you turn off the "Read Striping" feature in DrivePool (Pool Options -> Performance -> Read Striping), and see if that helps?

If not, enable file system logging and do this:

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

[Kevin]

I was just coming back to say I think its the external HDD. Its a brand new Seagate USB 3.0 drive (http://www.amazon.com/gp/product/B00TKFEEBW?psc=1&redirect=true&ref_=oh_aui_detailpage_o00_s00) plugged into one of the USB 3.0 ports on my server. Not sure why its being so slow but I did to some basic tests from DP to a local SSD and was getting sustained 145MBps. I'll look into this further this weekend. Sorry to jump the gun!!

[Christopher (Drashna)]

Sorry to jump the gun!!

It's not a problem at all.  It can be hard to troubleshoot performance or other issues normally, but DrivePool does add an additional layer of complexity to this (as it suffers from any disk or performance issues that any and all of the underlying disks suffer from, and this may not be immediately obvious).

 

 

I was just coming back to say I think its the external HDD. Its a brand new Seagate USB 3.0 drive (http://www.amazon.com/gp/product/B00TKFEEBW?psc=1&redirect=true&ref_=oh_aui_detailpage_o00_s00) plugged into one of the USB 3.0 ports on my server. Not sure why its being so slow but I did to some basic tests from DP to a local SSD and was getting sustained 145MBps. I'll look into this further this weekend. 

If you're using the 2.X version, you can open the performance UI section, and watch where the files are being read from. That may help identify any performance issues (at least in the future). 

 

And yeah, it could definitely be the external.  Not all USB 3.0 controllers are equal, and some don't perform as well as others. 

If you have StableBit Scanner installed, you can right click on the disk and select the "Burst Test" option, and this may give you a good idea of the max (theoretical) throughput that the disk is capable of (theoretical, because it can reach speeds faster than the drive actually can hit due to how the test works).