Hi, OMV and linux noob here, (but long IT nerdery experience). I put together an OMV box using the latest stable OMV 2 on an HP proliant server. I have two identical WD Red NAS hard drives mounted and used in a grey hole pool (Disk A is set up as the landing zone for the shares). Performance from disk B is perfectly adequate but read and write from disk A is extremely poor. I first noticed very slow writes to the samba shares but then noticed intermittent issues with playing movies on Plex. Some movies (which I later worked out are saved on disk A by greyhole) won't play more than a few seconds, others (stored on disk B) play fine.
I have followed the diagnostics from the sticky post at the top of this forum and everything looks ok until I get to the performance tests:
root@Beast:~# dd conv=fdatasync if=/dev/mapper/sda1-sda1 of=/tmp/test.img bs=1G count=3
3+0 records in
3+0 records out
3221225472 bytes (3.2 GB) copied, 825.229 s, 3.9 MB/s
root@Beast:~# dd if=/dev/mapper/sda1-sda1 of=/dev/null bs=1G count=3
3+0 records in
3+0 records out
3221225472 bytes (3.2 GB) copied, 650.054 s, 5.0 MB/s
The same tests on disk B look fine:
root@Beast:~# dd conv=fdatasync if=/dev/mapper/sdb1-sdb1 of=/tmp/test.img bs=1G count=3
3+0 records in
3+0 records out
3221225472 bytes (3.2 GB) copied, 29.2664 s, 110 MB/s
root@Beast:~# dd if=/dev/mapper/sdb1-sdb1 of=/dev/null bs=1G count=3
3+0 records in
3+0 records out
3221225472 bytes (3.2 GB) copied, 21.3882 s, 151 MB/s
I also ran the following:
root@Beast:~# sudo hdparm -Tt /dev/mapper/sda1-sda1
/dev/mapper/sda1-sda1:
Timing cached reads: 2 MB in 18.79 seconds = 108.99 kB/sec
Timing buffered disk reads: 2 MB in 15.69 seconds = 130.50 kB/sec
As you can see, not very good numbers. For the record, the identical drive B shows the following:
root@Beast:~# sudo hdparm -Tt /dev/mapper/sdb1-sdb1
/dev/mapper/sdb1-sdb1:
Timing cached reads: 24812 MB in 2.00 seconds = 12421.07 MB/sec
Timing buffered disk reads: 456 MB in 3.01 seconds = 151.69 MB/sec
As I said, I'm a linux noob so don't really know where to start investigating further to sort this out, so any help would be very welcome. Thanks in advance.