From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keld =?iso-8859-1?Q?J=F8rn?= Simonsen Subject: Re: Draft Mirrored Linux Mini How-to Date: Sat, 8 Aug 2009 13:36:44 +0200 Message-ID: <20090808113644.GA14028@rap.rap.dk> References: <4A78292A.5000607@in.ibm.com> <1249421223.18245.36.camel@pasglop> <4A794E26.8080207@in.ibm.com> <1249465934.18245.54.camel@pasglop> <4A7ADBB1.3050906@in.ibm.com> <1249595469.24311.5.camel@pasglop> <4A7B708F.4050406@uga.edu> <20090807095133.GB28746@rap.rap.dk> <4A7C5BD2.80508@uga.edu> <20090807173423.GA32127@rap.rap.dk> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Content-Disposition: inline In-Reply-To: <20090807173423.GA32127@rap.rap.dk> Sender: linux-raid-owner@vger.kernel.org To: Harold Pritchett Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids =46orgot to cc linux-raid... keld On Fri, Aug 07, 2009 at 07:34:23PM +0200, Keld J=F8rn Simonsen wrote: > On Fri, Aug 07, 2009 at 12:52:34PM -0400, Harold Pritchett wrote: > > Keld J=F8rn Simonsen wrote: > > > >> It is a good idea to have a how-to. But there are already a few ar= ound. > >> I wrote something like it for our wiki at > >> http://linux-raid.osdl.org/index.php/Preventing_against_a_failing_= disk > >> but with some more advanced features, such as you do not crash if = one > >> disk fails, and you can reboot the system without a rescue disk, a= nd you > >> get faster mirrored raid, avoiding the slow raid 1. It does not do= LVM, > >> however, and I think that how-to should be enhanced with LVM. > > > > I guess this would depend upon the linux. Currently, I am working = with > > Centos 5.3 and the only raid personalities available in the kernel = on > > the DVD appear to be RAID0, RAID1, RAID5, and RAID6. With two disk= s > > this limits us to RAID0 and RAID1. >=20 > I am also running centos 5.3 and raid10 is supported, and I run most = of > my data on it. >=20 > >>> I'm from the old school. I believe in lots of partitions. Creat= e any > >>> additional partitions you may need. If you really want to, you c= an > >>> just create a single partition and put "/" in it. You still will > >>> need the "/boot" partition since you can't boot from an LVM parti= tion. > >> > >> I think it is good to have a / , a /home, and possibly a /boot=20 > >> partition, but having more partitions is probably just shooting=20 > >> yourself in the > >> foot, because you may create space problems. Those smaill partitio= ns can > >> easily hit some roof, like /var (when logs run full) and /tmp (do= ing temporary > >> work like editing in big files), /opt and /usr/local (installing b= ig new packages) > >> and why should /usr and / be on different partition - that beats m= e. > > > > As I said, I'm from the old school originally cutting my teeth on B= SD unix in > > the 1980's. In those days, disks were always too small. A couple = of 20 MB > > disks (that's MB, not GB) was a LOT of space back then. By using m= ultiple > > partitions you could keep a run-away from crashing the whole system= when it > > filled up /tmp or /var. >=20 > I am also from that time, starting out with UNIX V6 on RL05 with 2.5 = MB on a PDP-11/45. > And we had a *big* 40 MB disk in the corner. Later we ran VAX'en and = BSD > 4.2 - still I think it is better to keep the system things in one > partition. Anyway why not describe both, and tell of pros and cons. >=20 > > But once again, this personal preferences. All you really need is = /boot, / and > > some swap space. >=20 > I agree with that. >=20 > >>> You can now continue to install linux normally. I usually do it = twice. > >>> the first time is to get an idea of how big each partition should= be > >>> and the second time is to get it right. > >> > >> That is cumbersome, and probably caused by your use of many partit= ions. > >> It will turn some novices off. > > > > Make the default a single partition and put the multiple partition = version in an > > appendix... In today's world of TeraByte disk drives for under $10= 0.00 It may > > be the best idea to just put it all in a single file system. >=20 > as sad you could decribe both. For pedagogical reasons, and because i= t > does not matter very much, you could probebly benefit from describing > the simpler version. >=20 > >> why can't you boot from the working drive? > >> The system should be configured to do this. > >> > >>> 4. Boot from the linux rescue CD/DVD and start the system, no ne= twork. > >> > >> better avoid the rescue cd by making the system bootable from both= drives.' > > > > can do... I just didn't think of this... > > > >>> 14. Wait for the mirror to sync. It may take several hours > >> > >> you can begin using the system immediately, while the raids are sy= ncing. > > > > Good point. I knew that and just didn't say it. > > > >> it would be nice if you could reference our wiki, wherever you put= up > >> your howto. > > > > I would be glad to... In fact, if we get something useful, you mig= ht want > > to put a copy on the wiki... >=20 > to me it is very overlapping with what is already up there. > For now I cannot see the benefit of two howtos with the same aim. > Better consolidate it. >=20 > best regards > keld -- 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