On 05/03/2015 14:10, Robert Schulze wrote:
Hi,
Am 04.03.2015 um 17:09 schrieb Steven Hartland:
Transaction sizes look like they are the same but the tps from gmirror
is significantly lower.
As iostat doesn't properly understand deletes it would still be nice to
see that gstat -d -p output as that will also give us queue depth.
Since gstat doesnt just output row by row, I had to screenshot a running
gstat and transcribe the values. Running gstat -b in a loop doesn't help
here, since the system is inresponsive and won't start any program in
time during the DELETE ops.
So after deleting a 2GB file on a gmirror with two active SSDs I get:
# gstat -dpfada -I3s
dT: 3.189s w: 3.000s filter: ada
L(q) ops/s r/s kBps ms/r w/s kBps ms/w d/s kBps ms/d %busy Name
0 3342 0 0 0.0 0 0 0.0 3342 106939 10.2 80.5| ada0
0 3342 0 0 0.0 0 0 0.0 3342 106939 10.0 82.0| ada1
9 2606 0 0 0.0 0 0 0.0 2606 83400 60.8 98.3| ada0
9 2606 0 0 0.0 0 0 0.0 2606 83400 56.9 98.7| ada1
46 1705 0 0 0.0 0 0 0.0 1705 54565 62.5 98.4| ada0
51 1704 0 0 0.0 0 0 0.0 1704 54512 62.9 97.6| ada1
22 1540 0 0 0.0 0 0 0.0 1540 49285 20.9 96.6| ada0
24 1541 0 0 0.0 0 0 0.0 1541 49317 21.8 96.0| ada1
2 1496 0 0 0.0 0 0 0.0 1496 47887 13.3 98.6| ada0
7 1495 0 0 0.0 0 0 0.0 1495 47855 14.1 98.9| ada1
11 1032 0 0 0.0 0 0 0.0 1032 33010 18.2 98.8| ada0
10 1033 0 0 0.0 0 0 0.0 1033 33070 15.4 98.1| ada1
12 775 0 0 0.0 0 0 0.0 775 24798 26.2 97.5| ada0
16 773 0 0 0.0 0 0 0.0 773 24746 29.6 98.5| ada1
65 743 0 0 0.0 0 0 0.0 743 23784 25.4 98.8| ada0
59 746 0 0 0.0 0 0 0.0 746 23887 24.4 99.0| ada1
These values look totally reasonable in terms a d/s.
How does this compare to the none gmirror case?
Try backing out r268816 and see if that has any impact.
could you please explain what you mean by that?
Compile a version of the kernel with this change reverted.
Details of the change can be seen here.
https://svnweb.freebsd.org/base?view=revision&revision=268816
You can download the changes (only ata is relevant in your case) and
apply the patch with reverse option.
Once you've done that recompile and re-install your kernel.
This feels like it might be an request ordering issue.
Regards
Steve
_______________________________________________
[email protected] mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-geom
To unsubscribe, send any mail to "[email protected]"
