From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jaromir Capik Subject: Re: [RFE] Please, add optional RAID1 feature (= chunk checksums) to make it more robust Date: Tue, 24 Jul 2012 11:09:00 -0400 (EDT) Message-ID: <1033621438.2057828.1343142540202.JavaMail.root@redhat.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Roberto Spadim Cc: stan@hardwarefreak.com, Linux RAID , Piergiorgio Sartor List-Id: linux-raid.ids > yeah, i think this too, but IMO Jamiro exposed a specific scenario, > let=C2=B4s get back to it and after check a generic scenario, > he is using small computers (i don=C2=B4t know if it=C2=B4s ARM or X8= 6) with > space to only 2 disks (i told him to use raid5 or raid6 because the > checksums but he don=C2=B4t have space for >=3D3 disks in computer ca= se, > maybe if we could run raid5 with 2 disks could help... or 1 disk... > just a idiot idea, but this could help...) I believe, that Piergiorgio meant something else. It was about creation of a high number of small partitions on two physical drives and then build a RAID6 array on top of them. But that's really a bit overkill :] > i don=C2=B4t know the real scenario, i think he will not use it in > 100partitions, maybe 4 or 5 partitions, and performance to be a > second > option, security is priority here > in the implementation of this new layer (maybe like LINEAR, MULTIPATH > or another not raid level) we could focus on security and after > performace >=20 > just some ideas... >=20 > 2012/7/23 Piergiorgio Sartor > > > > Hi all, > > > > actually, what you would like to do is already > > possible, albeit it will kill the performance > > of a rotating, mechanical, HDD. > > With SSD might work better. > > > > If you take an HDD and partition it, let's say > > with 100 partitions (GPT will be required), > > then you can build a RAID-6 using this 100 > > partitions, having a redundancy of 2%. > > Taking two, or more, of such configured RAID-6, > > it will be possible to build (with them) a > > RAID-1 (or else). > > > > If a check of this RAID-1 returns mismatches, > > it will be possible to check the single devices > > and find out which is not OK. > > With RAID-6 (per device), and a bit of luck, it > > will be possible to fix it directly. > > > > Of course a lot of variables are tunable here. > > For example the number of partitions, the chunk > > size, or even the fact that with X partitions > > it could be possible to build more than one RAID-6, > > increasing the effective redundancy. > > > > All with the performance price I mentioned at the > > beginning. > > > > bye, > > > > -- > > > > piergiorgio > > -- > > To unsubscribe from this list: send the line "unsubscribe > > linux-raid" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html >=20 >=20 >=20 >=20 > -- > Roberto Spadim > Spadim Technology / SPAEmpresarial >=20 -- 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