From mboxrd@z Thu Jan 1 00:00:00 1970 From: Smart Weblications GmbH Subject: Re: About sparse images Date: Sun, 26 Aug 2012 20:38:02 +0200 Message-ID: <503A6D0A.8050207@smart-weblications.de> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mx04.smart-weblications.de ([188.65.144.39]:57913 "EHLO mx04.smart-weblications.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753686Ab2HZSjD (ORCPT ); Sun, 26 Aug 2012 14:39:03 -0400 In-Reply-To: Sender: ceph-devel-owner@vger.kernel.org List-ID: To: =?ISO-8859-1?Q?S=E9bastien_Han?= Cc: ceph-devel Am 26.08.2012 20:11, schrieb S=E9bastien Han: > Hi all! >=20 > I know that ceph images (rbd) are sparse. It's good but I have some > interrogations about the ceph -s (-w) output. Let's say your create a > 10G image, map it, format it and mount it. Finally you filled up the > entire space available. You notice that the 'data' and 'used' space > had grown. Now delete the content of your image but **not** this > image, not now. You notice that nothing changed from the ceph output, > it's not surprising because of the sparse capability. At this point o= f > time the output from the command ceph is neither right nor wrong. It > only shows the space used by the sparse image, but it doesn't mean > that you have 'real' data in it, just a simple object allocation. It'= s > not so relevant, the only solution is to remove the image (obviously)= =2E > My feeling is that we should be careful about the ceph's output, it's > not a good indicator for 'real' data. Ok Ceph won't replace a > monitoring system but I'll be happy to trust the ceph output at 100% > :) >=20 > I would appreciate some reactions about that :) >=20 why not gather real image size with rbd info , sum up used s= pace, then look at ceph -s to get total avail space? --=20 Mit freundlichen Gr=FC=DFen, Smart Weblications GmbH Martinsberger Str. 1 D-95119 Naila fon.: +49 9282 9638 200 fax.: +49 9282 9638 205 24/7: +49 900 144 000 00 - 0,99 EUR/Min* http://www.smart-weblications.de -- Sitz der Gesellschaft: Naila Gesch=E4ftsf=FChrer: Florian Wiessner HRB-Nr.: HRB 3840 Amtsgericht Hof *aus dem dt. Festnetz, ggf. abweichende Preise aus dem Mobilfunknetz -- 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