I have 5.0 Unraid running on a Vmware Hypervisor with a dedicated M1015 controller connected to 5 4TB WD Red Drives. Below is my read and write speed when copying from a guest OS to and from the Unraid guest (these speeds match what I get from my HTPC):

 

Read: 6.56GB 2m11s [50.9 MB/s]

Write: 6.56GB 3m11s [35.2MB/s]

 

My issue is that when I am writing to Unraid I cannot read a 1080p video from it at the same time without a lot of stuttering. I use Plex to access my video collection and I am connecting locally so it is not transcoding the video in any way. Anyone have any insight into why I am not able to have smooth playback when writing to Unraid? I noticed my read speed does seem a little low (I would have expected 80 MB/s read and 40 MB/s write) but I wouldn't think that would be causing my issue.

 

I have attached my syslog.

 

Thank you for any help/insight provided.

syslog.txt

Actually I'd expect read speeds in the 90-110MB/s range with 4TB WD Reds.

 

Is this running under ESXi with the M1015 passed through?

 

Finally, do you still get stuttering if you're reading from a different disk than you're writing to?

 

Test the speed running bare-metal.

FYI:  I get 90-100MB/s reads from my WD 3TB reds on my WD ESXi server.  I'm even going through a SAS expander which should reduce the speeds a little when I'm doing concurrent reads.

 

 

I have 3 virtualized unRAID servers one has Seagate drives only,  2nd has Hitachi drives only, 3rd has WD 3TB drives only.

Sorry for late reply my switch broke last week and just got things back up and running.

 

It is interesting that I should be seeing a much better read speed. The tricky part of this problem is that it does not consistently happen so it is hard to test... sometimes I can be writing data and have no issues but other times I do have issues. I did preclear all of the drives and all performed well during the preclear.

 

Yes I did pass through the M1015 to the Unraid guest.

 

Any suggestions on things to look at to increase my read speed? I'm not sure where to start to begin addressing that issue but I figure if I get my read speed issue figured out then my stuttering would completely go away.