Re: osd_recovery_max_chunk value

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

 



Hi Christian,

Thank you for your help.

Ceph version is 12.2.2. So is this value bad ? Do you have any suggestions ?


So to reduce the max chunk ,I assume I can choose something like
7 << 20 ,ie 7340032 ?

Karun Josy

On Tue, Feb 6, 2018 at 1:15 PM, Christian Balzer <chibi@xxxxxxx> wrote:
On Tue, 6 Feb 2018 13:01:12 +0530 Karun Josy wrote:

> Hello,
>
> We are seeing slow requests while recovery process going on.
>
> I am trying to slow down the recovery process. I set  osd_recovery_max_active
> and  osd_recovery_sleep as below :
> ----------
> ceph tell osd.* injectargs '--osd_recovery_max_active 1'
> ceph tell osd.* injectargs '--osd_recovery_sleep .1'
> ----------
What version of Ceph, in some "sleep" values will make things _worse_!
Would be nice if that was documented in like, the documentation...

>
> But I am confused with the  osd_recovery_max_chunk. Currently, it shows
> 8388608.
>
> # ceph daemon osd.4 config get osd_recovery_max_chunk
> {
>     "osd_recovery_max_chunk": "8388608"
>
>
> In ceph documentation, it shows
>
> -----------
> osd recovery max chunk
> Description: The maximum size of a recovered chunk of data to push.
> Type: 64-bit Unsigned Integer
> Default: 8 << 20
> ------------
>
> I am confused. Can anyone let me know what is the value that I have to give
> to reduce this parameter ?
>
This is what you get when programmers write docs.

The above is a left-shift operation, see for example:
http://bit-calculator.com/bit-shift-calculator

Now if shrinking that value is beneficial for reducing recovery load,
that's for you to find out.

Christian

>
>
> Karun Josy


--
Christian Balzer        Network/Systems Engineer
chibi@xxxxxxx           Rakuten Communications

_______________________________________________
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]     [Ceph Dev]     [Linux USB Development]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [xfs]


  Powered by Linux