From: Zoltan Szecsei <zoltans@geograph.co.za>
To: Mikael Abrahamsson <swmike@swm.pp.se>
Cc: linux-raid@vger.kernel.org
Subject: Re: Confusion with setting up new RAID6 with mdadm
Date: Mon, 15 Nov 2010 14:27:45 +0200 [thread overview]
Message-ID: <4CE12741.6070803@geograph.co.za> (raw)
In-Reply-To: <alpine.DEB.1.10.1011141745400.1154@uplift.swm.pp.se>
On 2010-11-14 18:48, Mikael Abrahamsson wrote:
>
>> *What is the correct fdisk or parted method get rid of the DOS & GPT
>> flags, and create a correctly aligned partition, and should this be a
>> 0xda partiton (& then I use metatdata 1.2 for mdadm)?
>
> I just "dd if=/dev/zero of=/dev/sdX bs=1024000 count=1" to zero the
> first megabyte of the drive to get rid of the partition table (you get
> rid of the v1.2 metadata at the same time actually). Then you know for
> sure you're correctly aligned as well as md is 4k aligned.
I did this on all 8 drives (/dev/sd[a-h])
root@gs0:/etc# dd if=/dev/zero of=/dev/sdb bs=1024000 count=1
1+0 records in
1+0 records out
1024000 bytes (1.0 MB) copied, 0.0103209 s, 99.2 MB/s
root@gs0:/etc# dd if=/dev/zero of=/dev/sdc bs=1024000 count=1
But the GPT id has not disappeared. I am going to use these drives
unpartitioned, so is this a problem?
Thanks,
Zoltan
root@gs0:/etc# fdisk -lu
WARNING: GPT (GUID Partition Table) detected on '/dev/sda'! The util
fdisk doesn't support GPT. Use GNU Parted.
Disk /dev/sda: 2000.4 GB, 2000398934016 bytes
255 heads, 63 sectors/track, 243201 cylinders, total 3907029168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
Disk /dev/sda doesn't contain a valid partition table
WARNING: GPT (GUID Partition Table) detected on '/dev/sdb'! The util
fdisk doesn't support GPT. Use GNU Parted.
Disk /dev/sdb: 2000.4 GB, 2000398934016 bytes
255 heads, 63 sectors/track, 243201 cylinders, total 3907029168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
Disk /dev/sdb doesn't contain a valid partition table
WARNING: GPT (GUID Partition Table) detected on '/dev/sdc'! The util
fdisk doesn't support GPT. Use GNU Parted.
Disk /dev/sdc: 2000.4 GB, 2000398934016 bytes
255 heads, 63 sectors/track, 243201 cylinders, total 3907029168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
Disk /dev/sdc doesn't contain a valid partition table
WARNING: GPT (GUID Partition Table) detected on '/dev/sdd'! The util
fdisk doesn't support GPT. Use GNU Parted.
Disk /dev/sdd: 2000.4 GB, 2000398934016 bytes
255 heads, 63 sectors/track, 243201 cylinders, total 3907029168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
Disk /dev/sdd doesn't contain a valid partition table
WARNING: GPT (GUID Partition Table) detected on '/dev/sde'! The util
fdisk doesn't support GPT. Use GNU Parted.
Disk /dev/sde: 2000.4 GB, 2000398934016 bytes
255 heads, 63 sectors/track, 243201 cylinders, total 3907029168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
Disk /dev/sde doesn't contain a valid partition table
WARNING: GPT (GUID Partition Table) detected on '/dev/sdf'! The util
fdisk doesn't support GPT. Use GNU Parted.
Disk /dev/sdf: 2000.4 GB, 2000398934016 bytes
255 heads, 63 sectors/track, 243201 cylinders, total 3907029168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
Disk /dev/sdf doesn't contain a valid partition table
WARNING: GPT (GUID Partition Table) detected on '/dev/sdg'! The util
fdisk doesn't support GPT. Use GNU Parted.
Disk /dev/sdg: 2000.4 GB, 2000398934016 bytes
255 heads, 63 sectors/track, 243201 cylinders, total 3907029168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
Disk /dev/sdg doesn't contain a valid partition table
WARNING: GPT (GUID Partition Table) detected on '/dev/sdh'! The util
fdisk doesn't support GPT. Use GNU Parted.
Disk /dev/sdh: 2000.4 GB, 2000398934016 bytes
255 heads, 63 sectors/track, 243201 cylinders, total 3907029168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
Disk /dev/sdh doesn't contain a valid partition table
Disk /dev/sdi: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 cylinders, total 976773168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000e30c7
Device Boot Start End Blocks Id System
/dev/sdi1 * 2048 391167 194560 83 Linux
Partition 1 does not end on cylinder boundary.
/dev/sdi2 393214 976771071 488188929 5 Extended
/dev/sdi5 393216 98047999 48827392 83 Linux
/dev/sdi6 98050048 110047231 5998592 82 Linux swap / Solaris
/dev/sdi7 110049280 976771071 433360896 83 Linux
root@gs0:/etc#
--
===========================================
Zoltan Szecsei PrGISc [PGP0031]
Geograph (Pty) Ltd.
P.O. Box 7, Muizenberg 7950, South Africa.
65 Main Road, Muizenberg 7945
Western Cape, South Africa.
34° 6'16.35"S 18°28'5.62"E
Tel: +27-21-7884897 Mobile: +27-83-6004028
Fax: +27-86-6115323 www.geograph.co.za
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next prev parent reply other threads:[~2010-11-15 12:27 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-11-14 15:36 Confusion with setting up new RAID6 with mdadm Zoltan Szecsei
2010-11-14 16:48 ` Mikael Abrahamsson
2010-11-15 12:27 ` Zoltan Szecsei [this message]
2010-11-15 12:47 ` Michal Soltys
2010-11-15 13:23 ` Zoltan Szecsei
2010-11-14 19:50 ` Luca Berra
2010-11-15 6:52 ` Zoltan Szecsei
2010-11-15 7:41 ` Luca Berra
2010-11-15 11:06 ` Zoltan Szecsei
2011-07-22 1:08 ` Tanguy Herrmann
2011-07-22 5:17 ` Mikael Abrahamsson
2010-11-14 22:13 ` Neil Brown
2010-11-15 5:30 ` Roman Mamedov
2010-11-15 6:58 ` Zoltan Szecsei
2010-11-15 7:43 ` Mikael Abrahamsson
2010-11-15 9:18 ` Neil Brown
2010-11-15 18:01 ` Zoltan Szecsei
2010-11-15 19:53 ` Neil Brown
2010-11-16 6:48 ` Zoltan Szecsei
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