chunksize does have an important meaning in the linear case: it's
'rounding'. We cannot change this unilaterally (it breaks backwards
compatibility), and it does make sense i believe. [certain disks serve
requests faster which have proper alignment and size. I do not think we
should assume that an arbitrarily misaligned IO request will perform
identically.] So i'll fix raidtools to enforce chunksize in the linear
case (maybe introduce a 'rounding' keyword?).
Ingo
On Fri, 26 Nov 1999, Jakub Jelinek wrote:
> On Fri, Nov 26, 1999 at 09:43:06AM +0100, [EMAIL PROTECTED] wrote:
> > Hallo,
> >
> > I have a Sparc 10 with Linux6.1 running I have two disks of 1Gb and
> > 1.7Gb.
> > I would like to do a linear raid but when I do "raidstart -a /dev/md0
> > into shell I receive -> /dev/md0: Invalid argument <-
> > and into consolle
> > (read) sdb1's sb offset:1026048 [events: 20202020]
> > md: invalid raid superblock magic on sdb1
> > md: sdb1 has invalid sb, not importing!
> > could not import sdb1!
> > autostart sdb1 failed!
> > My kernel is 2.2.12-42 and raidtools-0.90
> > If I do mkraid /dev/md0 I receive into shell
> > ->handling MD device /dev/md0
> > analyzing super-block
> > disk 0: /dev/sdb1, 1026144kB, raid superblock at 1026048kB
> > disk 1: /dev/sdc1, 1720345kB, raid superblock at 1720256kB
> > /dev/md0: Invalid argument and into consolle I receive some messages
> > that they are into file attach messages.
> > My /etc/raidtab is:
> > raiddev /dev/md0
> > raid-level linear
> > nr-raid-disks 2
> > nr-spare-disks 0
> > persistent-superblock 1
>
> put
> chunk-size 8
>
> here and redo mkraid (possibly with -f).
> It seems that the kernel is checking chunk size always, while raidtools are
> checking chunk size for raid0,1,4,5 only.
> IMHO kernel should not check chunk size for other raid levels, but if Ingo
> thinks it should, then raidtools should either error on not specified
> chunk-size for other levels as well or supply some default which will not
> trigger the md.c MD_BUG().
>
> Cheers,
> Jakub
> ___________________________________________________________________
> Jakub Jelinek | [EMAIL PROTECTED] | http://sunsite.mff.cuni.cz/~jj
> Linux version 2.3.18 on a sparc64 machine (1343.49 BogoMips)
> ___________________________________________________________________
>
