On 1/10/20 7:43 PM, Philip Brown wrote:
> Surprisingly, a google search didnt seem to find the answer on this, so guess
> I should ask here:
>
> what determines if an rdb is "100% busy"?
>
> I have some backend OSDs, and an iSCSI gateway, serving out some RBDs.
>
> iostat on the gateway says rbd is 100% utilized
>
> iostat on individual OSds only goes as high as about 60% on a per-device
> basis.
> CPU is idle.
> Doesnt seem like network interface is capped either.
>
> So.. how do I improve RBD throughput?
>
The util is calculated based on average waits, see:
https://coderwall.com/p/utc42q/understanding-iostat
Just improving performance isn't just turning a knob and it will happen.
It seems like your RBD can't flush it's I/O fast enough and that causes
the iowait to go up.
This can be all kinds of things:
- Network (latency)
- CPU on the OSDs
Wido
>
>
> --
> Philip Brown| Sr. Linux System Administrator | Medata, Inc.
> 5 Peters Canyon Rd Suite 250
> Irvine CA 92606
> Office 714.918.1310| Fax 714.918.1325
> pbr...@medata.com| www.medata.com
> _______________________________________________
> ceph-users mailing list
> ceph-users@lists.ceph.com
> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
>
_______________________________________________
ceph-users mailing list
ceph-users@lists.ceph.com
http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
