Re: Reducing I/O when increasing number of PGs

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Wed, Jan 22, 2014 at 9:13 AM, Caius Howcroft
<caius.howcroft@xxxxxxxxx> wrote:
> Hi all,
>
>
> I want to double the number of pgs available for a pool, however I
> want to reduce as much as possible the resulting I/O storm (I have
> quite a bit of data in these pools).
>
> What is the best way of doing this? Is it using php_nums? for example:
>
> increase pg_num form X to 2X
> while pgp_num < pg_num:
>   increase pgp_num by 10%
>   wait for health_ok
>
> Or is there a better way, like setting the number of simulataenous operations?

Doing it this way certainly lets you control the pain a little more.
We have other options like, indeed, controlling the number of
simultaneous operations on any given OSD, but as long as you don't
mind babysitting I'd probably do it with the pgp_num loop. It's easier
to deal with externalities that way and reduces the amount of
insta-map-churn that's going to happen.
-Greg
Software Engineer #42 @ http://inktank.com | http://ceph.com
_______________________________________________
ceph-users mailing list
ceph-users@xxxxxxxxxxxxxx
http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com




[Index of Archives]     [Information on CEPH]     [Linux Filesystem Development]     [Ceph Development]     [Ceph Large]     [Linux USB Development]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [xfs]


  Powered by Linux