From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Williams Subject: Re: [PATCH] (Re: Questions regarding startup of imsm container) Date: Wed, 24 Mar 2010 07:49:46 -0700 Message-ID: References: <7db987b31003222056i46c42112s541ba949821a6759@mail.gmail.com> <20100323080419.GA9374@maude.comedia.it> <20100324115749.1ac9d6f8@notabene.brown> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <20100324115749.1ac9d6f8@notabene.brown> Sender: linux-raid-owner@vger.kernel.org To: Neil Brown Cc: Luca Berra , linux-raid@vger.kernel.org List-Id: linux-raid.ids On Tue, Mar 23, 2010 at 5:57 PM, Neil Brown wrote: > On Tue, 23 Mar 2010 09:04:19 +0100 > Luca Berra wrote: > >> On Mon, Mar 22, 2010 at 09:56:01PM -0600, Randy Terbush wrote: >> >Having a go at building a raid5 array using the new imsm support an= d >> >having good luck keeping drives in the array, etc. Nice work. I hav= e a >> >few questions though as I am having some trouble figuring out how t= o >> >properly start this container. >> > >> ># mdadm --version >> >mdadm - v3.1.2 - 10th March 2010 >> > >> ># mdadm -Es >> >ARRAY metadata=3Dimsm UUID=3D30223250:76fd248b:50280919:0836b7f0 >> >ARRAY /dev/md/Volume0 container=3D30223250:76fd248b:50280919:0836b7= f0 >> >member=3D0 UUID=3D8a4ae452:da1e7832:70ecf895:eb58229c >> > >> ># ls -l /dev/md/ >> >total 0 >> >lrwxrwxrwx 1 root root 6 Mar 22 20:54 0 -> ../md0 >> >lrwxrwxrwx 1 root root 8 Mar 22 20:54 127 -> ../md127 >> >lrwxrwxrwx 1 root root 8 Mar 22 20:54 Volume0_0 -> ../md127 >> > >> >As you can see, the name for the link in /dev/md does not agree wit= h >> >the name that the Examine is coming up with. >> please read mdadm.conf manpage, under the section "HOMEHOST" >> >> >Is it better to just forgo the ARRAY statements and go with an AUTO= +imsm? >> > >> >And last, does the concept of a write-intent bitmap make sense on a= n >> >imsm container? If so, I get a segv if trying to run mdadm /dev/mdX >> >-Gb internal on either device. >> >> i don't believe it makes sense at all, surely imsm do not support an >> internal bitmap (no provisioning for it in the metadata) >> >> The attached patch completely disables bitmap support for arrays wit= h >> externally managed metadata. > > Thanks for the patch. =A0However I would prefer to disable bitmap sup= port for > those metadata formats which report that they don't support it. > Thus the following patch. > > Thanks, > NeilBrown > > > + =A0 =A0 =A0 =A0 =A0 =A0 =A0 if (!st->ss->add_internal_bitmap) { [..] > + =A0 =A0 =A0 =A0 =A0 =A0 =A0 if (st->ss->add_internal_bitmap =3D=3D = NULL) { [..] > + =A0 =A0 =A0 =A0 =A0 =A0 =A0 } else if (!st->ss->locate_bitmap) { The smallest of nits, or maybe just a clarification. I believe you have said in the past that you prefer the readability of positive-logic if statements where possible. -- Dan -- To unsubscribe from this list: send the line "unsubscribe linux-raid" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html