From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gregory Farnum Subject: Re: Do not understand some terms about cluster health Date: Fri, 23 Dec 2011 11:46:17 -0800 Message-ID: References: <8512670932FB654F81AF0FEF1BE6D49DA7E3E2@WHQBEMAIL1.whq.wistron> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mail-iy0-f174.google.com ([209.85.210.174]:33758 "EHLO mail-iy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752414Ab1LWTqS convert rfc822-to-8bit (ORCPT ); Fri, 23 Dec 2011 14:46:18 -0500 Received: by iaeh11 with SMTP id h11so15528689iae.19 for ; Fri, 23 Dec 2011 11:46:17 -0800 (PST) In-Reply-To: Sender: ceph-devel-owner@vger.kernel.org List-ID: To: Eric_YH_Chen@wistron.com Cc: ceph-devel@vger.kernel.org, Chris_YT_Huang@wistron.com On Thu, Dec 22, 2011 at 12:40 PM, Gregory Farnum wrote: > On Wed, Dec 21, 2011 at 7:47 PM, =A0 wrote: >> Hi, All >> >> =A0 When I type 'ceph health' to get the status of cluster, it will = show >> some information. >> >> =A0 Would you please to explain the term? >> >> =A0 Ex: HEALTH_WARN 3/54 degraded (5.556%) >> >> =A0 =A0 =A0 =A0 What does "degraded" mean ? =A0Is it a serious error= and how to >> fix it ? >> >> =A0 Ex: HEALTH_WARN 264 pgs degraded, 6/60 degraded (10.000%); 3/27 >> unfound (11.111%) > There are two meanings of degraded here. The degraded PGs are those > which don't yet have the number of active OSDs as they should (ie, th= e > PG wants 3 OSDs to be holding it and only 2 are). The number of > degraded objects is the number of missing replicas of objects. The > difference here is that an OSD can be an active member of a PG withou= t > holding all the objects yet; the general sequence is that you lose an > OSD so a bunch of PGs go degraded, and then the OSDs peer and bring i= n > a new replica so the PG is no longer degraded but most of the objects > are until they get copied over. > Unfound objects are those which the cluster believes should exist but > can't find anywhere, either because the only copy is on a down OSD or > because there's a bug which caused them to believe in non-existent > objects. > Are you using the RADOS gateway? If you are, that's probably where > your unfound objects came from; there was a long-standing accounting > bug which had a fix merged earlier this week. > >> =A0 =A0 =A0 =A0 What does "unfound" mean? =A0Could we recover the da= ta? >> =A0 =A0 =A0 =A0 Would it cause the whole data in rbd image corrupted= and never >> access ? > Nope; unfound objects will only block access to that specific object. > I'll have to look into whether rbd could trigger the same bug that RG= W > was or not. And the answer to this appears to be "no". If you've got unfound objects and you aren't using the Rados Gateway, we should figure out how it happened! Do you have any down OSDs? -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html