From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Hardy Subject: Re: Newbie questions: Max Active disks, RAID migration, Compiling mdadm 2.3 Date: Sat, 04 Feb 2006 18:13:02 -0800 Message-ID: <43E55F2E.1060102@h3c.com> References: <10AE6EFE-5542-4B43-8E19-87A66C4FFE6D@mac.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <10AE6EFE-5542-4B43-8E19-87A66C4FFE6D@mac.com> Sender: linux-raid-owner@vger.kernel.org To: Martin Ritchie , linux-raid@vger.kernel.org List-Id: linux-raid.ids If you remove the '-Werror' it'll compile and work, but you still can't convert a raid 0 to a raid 5. You're raid level understanding is off as well, raid 5 is a parity block rotating around all drives, you were thinking of raid 4 which has a single parity disk. Migrating raid 0 to raid 4 (and vice versa) should be possible technically, but I don't think it's implemented anywhere You should be able to have more than 4 active drives though. I am at this moment building an array with 6 components, I'm running a few with more than that, and these are by no means the largest arrays that peopl= e are running - just examples of it working. -Mike Martin Ritchie wrote: > Sorry if these are total newbie questions. >=20 > Why can't I have more than 4 active drives in my md RAID? >=20 > Why can't I easily migrate a RAID 0 to RAID 5. As I see it RAID 0 is=20 > just RAID 5 with a failed parity check drive? >=20 > Perhaps this is a limitation of the old v1.11 that FC4 updates to. >=20 > I tried to compile 2.3 but I get this error: >=20 > $make > gcc -Wall -Werror -Wstrict-prototypes -DCONFFILE=3D\"/etc/mdadm.conf\= " - > ggdb -DSendmail=3D\""/usr/sbin/sendmail -t"\" -c -o super0.o super0= =2Ec > In file included from super0.c:31: > /usr/include/asm/byteorder.h:6:2: error: #warning using private kern= el > header; include instead! > make: *** [super0.o] Error 1 >=20 > I'm not too familiar with compiling this sort of thing. (I usually l= ive > further away from the hardware and endian issues). I'm guessing ther= e > is some sort of option i have to specify to say that this should use > the private kernel headers. Including endian.h instead didn't help: >=20 > $make > gcc -Wall -Werror -Wstrict-prototypes -DCONFFILE=3D\"/etc/mdadm.conf\= " - > ggdb -DSendmail=3D\""/usr/sbin/sendmail -t"\" -c -o super0.o super0= =2Ec > cc1: warnings being treated as errors > super0.c: In function =91add_internal_bitmap0=92: > super0.c:737: warning: implicit declaration of function =91__cpu_to_l= e32=92 > super0.c:742: warning: implicit declaration of function =91__cpu_to_l= e64=92 > make: *** [super0.o] Error 1 >=20 > Oh just because I know it is going to be an issue I'm building on a=20 > Athlon 64... my first 64bit linux box so I'm sure there are going to = be > gotchas that I've not thought about. >=20 > Is there somewhere I over looked for finding this information. >=20 > TIA - 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