Messages in this thread |  | | Date | Sat, 10 Nov 2001 12:55:36 +0100 (CET) | From | Terje Eggestad <> | Subject | Re: confused about raw-io blocksizes |
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On Fri, 9 Nov 2001, Andreas Dilger wrote:
> On Nov 10, 2001 00:52 +0100, Terje Eggestad wrote: > > I'm curious as to what sets the smallest legal blocksize for raw-io, I > > get different values for different partitions on the same disk drive. > > > > In all my tests I've used > > raw /dev/raw/raw2 <block speclial file> > > and to test block size: > > dd if=/dev/raw/raw2 of=/dev/null bs=N count=1 > > where N is either 512, 1024, or 4096. > > (I've a RH7.1 with a dd that do propper buffer alignment) > > Failure is always "invalid argument" which singify either misaligned > > buffer or illegal read length. > > > > What confuses me is that when raw2 is bound to /dev/hda bs=512 is ok. > > However when binding raw2 to the different partitions on /dev/hda, some > > are ok with 512, some will only accept 1024, and one required 4096. > > It may be getting confused with the filesystem blocksize. Check tune2fs -l > for those devices. > > > When creating an lvm vg on one partition (/dev/hda6), and I've created > > two logical volumes on it, one was ok with 1024 and the other required > > 4096. When binding a raw to /dev/hda6 dd with bs=512 was ok. > > LVM is broken in this regard, unless you have a recent patch (Linus' > kernel does not). I sent him a patch to fix that, but it did not get in.
I'm been trying with RH 2.4.2-2, stock 2.4.10, stock 2.4.13, and a RH 2.4.3 with some additional patches. All of them has lvm 0.9.1_beta2 (isn't that getting old??)
That patch of ours may fix my problem, could you forward it to me please? Is it included in later lvm versin from sistna? I really want to be using lvm for the oracle partitions.
> > What kernel version/LVM do you have? Are you using LVM on all of these > partitions, or only some? Did you have filesystems on them? >
The two disk I've used for exploration is: /dev/hda1 * 1 500 4016218+ 83 Linux /dev/hda2 501 935 3494137+ 5 Extended /dev/hda5 501 564 514048+ 82 Linux swap /dev/hda6 565 935 2980026 8e Linux LVM
hda bs=512, hda1 bs=4096, hda2 bs=512, hda5 bs=512, hda6 bs=512
/dev/hda1 1 102 51376+ 83 Linux /dev/hda2 103 20928 10496304 5 Extended /dev/hda5 103 12293 6144232+ 83 Linux /dev/hda6 12294 12903 307408+ 82 Linux swap /dev/hda7 12904 20928 4044568+ 83 Linux
hda bs=512, hda1 bs=1024, hda2 bs=512, hda5 bs=1024, hda6 bs=512, hda7 bs=1024
Looks like your absolutly right about the fs, they're the only one causing trouble.
The lvm volumes was zero out by dd if=/dev/zero of=loc.block.spec.file the only reason I started with disk partitions was to try to figure out what was going on.
Thx TJ
> Cheers, Andreas > -- > Andreas Dilger > http://sourceforge.net/projects/ext2resize/ > http://www-mddsp.enel.ucalgary.ca/People/adilger/ > > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ >
-- _________________________________________________________________________
Terje Eggestad terje.eggestad@scali.no Scali Scalable Linux Systems http://www.scali.com
Olaf Helsets Vei 6 tel: +47 22 62 89 61 (OFFICE) P.O.Box 70 Bogerud +47 975 31 574 (MOBILE) N-0621 Oslo fax: +47 22 62 89 51 NORWAY _________________________________________________________________________
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