From: Neil Brown <neilb@suse.de>
To: Janos Haar <janos.haar@netcenter.hu>
Cc: linux-raid@vger.kernel.org
Subject: Re: RAID0 size bug (?)
Date: Sun, 10 Oct 2010 07:01:27 +1100 [thread overview]
Message-ID: <20101010070127.616ad1d6@notabene> (raw)
In-Reply-To: <0c3201cb67e5$7b064010$0400a8c0@dcccs>
On Sat, 9 Oct 2010 21:09:16 +0200
"Janos Haar" <janos.haar@netcenter.hu> wrote:
>
> ----- Original Message -----
> From: "Neil Brown" <neilb@suse.de>
> To: "Janos Haar" <janos.haar@netcenter.hu>
> Cc: <linux-raid@vger.kernel.org>
> Sent: Saturday, October 09, 2010 1:45 AM
> Subject: Re: RAID0 size bug (?)
>
>
> > On Sat, 9 Oct 2010 00:56:38 +0200
> > "Janos Haar" <janos.haar@netcenter.hu> wrote:
> >
> >> Hello list,
> >>
> >> Maybe a known old bug, but i don't know.
> >>
> >> The size is wrong of the md8:
> >>
> >> [root@UNISTORE ~]# fdisk -l /dev/sdh
> >>
> >> Disk /dev/sdh: 750.1 GB, 750156374016 bytes
> > ^^^^^^^^^
> >> 255 heads, 63 sectors/track, 91201 cylinders
> >> Units = cylinders of 16065 * 512 = 8225280 bytes
> >
> > So 750GB
> >
> >>
> >> Disk /dev/sdh doesn't contain a valid partition table
> >> [root@UNISTORE ~]# fdisk -l /dev/sdf
> >>
> >> Disk /dev/sdf: 500.1 GB, 500107862016 bytes
> > ^^^^^^^^^
> >> 255 heads, 63 sectors/track, 60801 cylinders
> >> Units = cylinders of 16065 * 512 = 8225280 bytes
> >
> > This one is 500GB
> >
> >
> >>
> >> Disk /dev/sdf doesn't contain a valid partition table
> >> [root@UNISTORE ~]# mdadm --detail /dev/md8
> >> /dev/md8:
> >> Version : 00.90.03
> >> Creation Time : Sat Oct 9 06:36:36 2010
> >> Raid Level : raid0
> >> Array Size : 1220961088 (1164.40 GiB 1250.26 GB)
> > ^^^^^^^^^^^
> >
> > 750GB + 500GB == 1250 GB
> >
> > So what is your problem?
>
> Shouldn't be 2x500GB?
> ...because this is stripe, not linear array. :-)
>
> I mean should be used the smallest drive's size, no?
No.
Try
man 4 md
and read the section in 'RAID0'.
NeilBrown
>
> >
> > NeilBrown
> >
> >
> >> Raid Devices : 2
> >> Total Devices : 2
> >> Preferred Minor : 8
> >> Persistence : Superblock is not persistent
> >>
> >> Update Time : Sat Oct 9 06:36:36 2010
> >> State : clean
> >> Active Devices : 2
> >> Working Devices : 2
> >> Failed Devices : 0
> >> Spare Devices : 0
> >>
> >> Chunk Size : 64K
> >>
> >> Number Major Minor RaidDevice State
> >> 0 8 112 0 active sync /dev/sdh
> >> 1 8 80 1 active sync /dev/sdf
> >> [root@UNISTORE ~]#
> >> [root@UNISTORE ~]# uname -a
> >> Linux UNISTORE 2.6.28.10 #5 SMP Fri Jan 29 07:40:35 CET 2010 x86_64
> >> x86_64
> >> x86_64 GNU/Linux
> >> [root@UNISTORE ~]# mdadm -V
> >> mdadm - v2.5.4 - 13 October 2006
> >> [root@UNISTORE ~]#
> >>
> >>
> >> Cheers,
> >> Janos
> >>
> >> --
> >> 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
prev parent reply other threads:[~2010-10-09 20:01 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-10-08 22:56 RAID0 size bug (?) Janos Haar
2010-10-08 23:45 ` Neil Brown
2010-10-09 19:09 ` Janos Haar
2010-10-09 20:01 ` Neil Brown [this message]
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