All of lore.kernel.org
 help / color / mirror / Atom feed
From: Jeff Wu <cpwu@tnsoft.com.cn>
To: ceph-devel@vger.kernel.org
Cc: Sage Weil <sage@newdream.net>
Subject: Questions about PG ID to OSDs
Date: Mon, 21 Feb 2011 17:05:35 +0800	[thread overview]
Message-ID: <1298279135.1867.34.camel@cephhost> (raw)


Hi ,
I'm reading CRUSH and RADOS thesis,from these thesis , 
i can get the algorithms:

object_id = <object_number,inode_number>;
pg_id = (r,hash(object_id) & mask)  ;   // closely resembles consistent
hashing

but i am wondering how to map a pg_id to OSDs by CRUSH .
Example , 
if pg_id = 1.12,exist osd0,osd1,osd2,osd3,
then how to map pg_id = 1.12 to these osds ?  the algorithms ? the
detail steps ?

Thanks a lot.

Jeff .C.P.Wu



             reply	other threads:[~2011-02-21  9:06 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-02-21  9:05 Jeff Wu [this message]
2011-02-21 20:30 ` Questions about PG ID to OSDs Sage Weil

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1298279135.1867.34.camel@cephhost \
    --to=cpwu@tnsoft.com.cn \
    --cc=ceph-devel@vger.kernel.org \
    --cc=sage@newdream.net \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.