From mboxrd@z Thu Jan 1 00:00:00 1970 From: mark delfman Subject: Re: -z not on RAID0 / MPIO hurdle Date: Fri, 14 Aug 2009 09:29:39 +0100 Message-ID: <66781b10908140129t4fc0947ek1e6f211758a2e969@mail.gmail.com> References: <66781b10908121144n1f053b57led29391534614b7@mail.gmail.com> <87d4705uxm.fsf@frosties.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <87d4705uxm.fsf@frosties.localdomain> Sender: linux-raid-owner@vger.kernel.org To: Goswin von Brederlow Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids Hi Goswin, I am not sure that this would work well for us... we would have you use LVM to create individual block targerts, then use MD to create RAIDs and then LVM again to create pools. We would ideally stay to LVM on all our raids (whether 0 / 6 etc). so would like to keep it in there... Does any know if there is a reason -z doesn=E2=80=99t work with RAID0 (= i mean is it designed to not work because of abc reason, or simply its never been needed etc)? Thank you for you help Mark D On Thu, Aug 13, 2009 at 3:06 AM, Goswin von Brederlow wrote: > mark delfman writes: > >> Hi.... I am hopeful that the group could provide me with some advice >> regarding limiting the drive size on a RAID0. =C2=A0I know and use t= he =E2=80=93z >> option for other raid levels, but this seems to have no effect on >> RAID0. >> >> I am sure many will ask =E2=80=98why bother=E2=80=99 or =E2=80=98use= fdisk=E2=80=99 but the problem is: >> >> We need to have some preserved information on each drive =E2=80=93 c= an be only >> a few MB at the end of the drive for example >> In the past we have simply used Fdisk to partition, save our data on >> Sdx2 and used Mdadm on Sdx1 =C2=A0(which works fine) >> But we are looking to move to dual channel SAS drives and use DM MPI= O >> >> DM MPIO works fine also, but not on the partitions, only the whole >> drive. =C2=A0So when we MDadm DMx it overwrites the SdX2 partition e= tc. >> >> The answer was that we used the =E2=80=93z and limited the drive siz= e and >> simply used DD to write our data to the end LBA=E2=80=99s.... >> >> But on RAID0 the =E2=80=93z does not seem to function, so I cant thi= nk of a >> way around this =EF=81=8C =C2=A0(other than changing the LBA range i= n the drive and >> this is restricted I think) >> >> >> Does anyone have any ideas? =C2=A0I appreciate any help > > LVM and --setphysicalvolumesize on pvcreate? > > MfG > =C2=A0 =C2=A0 =C2=A0 =C2=A0Goswin > -- 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