Storage space partition

[Bob McClure Jr]

On Fri, Apr 14, 2006 at 02:44:35PM -0400, Nair, Murlidharan T wrote:
> 
> 
> -----Original Message-----
> From: redhat-install-list-bounces at redhat.com
> [mailto:redhat-install-list-bounces at redhat.com] On Behalf Of Bob McClure
> Jr
> Sent: Friday, April 14, 2006 1:17 PM
> To: Getting started with Red Hat Linux
> Subject: Re: Storage space partition
> 
> On Fri, Apr 14, 2006 at 11:46:24AM -0400, Nair, Murlidharan T wrote:
> > 
> > <much snippage>
> > 
> I encountered some problem when I did used vgcreate. I am appending
> below the screen output of what I did and the errors I got. 
> Is there something that I missed? 
> 
> 
> 
> [root at bioinformatics ~]# fdisk /dev/emcpowera
> Device contains neither a valid DOS partition table, nor Sun, SGI or OSF
> disklabel
> Building a new DOS disklabel. Changes will remain in memory only,
> until you decide to write them. After that, of course, the previous
> content won't be recoverable.

That's normal.

> The number of cylinders for this disk is set to 85113.
> There is nothing wrong with that, but this is larger than 1024,
> and could in certain setups cause problems with:
> 1) software that runs at boot time (e.g., old versions of LILO)
> 2) booting and partitioning software from other OSs
>    (e.g., DOS FDISK, OS/2 FDISK)
> Warning: invalid flag 0x0000 of partition table 4 will be corrected by
> w(rite)

That's reasonable.

> Command (m for help): m
> Command action
>    a   toggle a bootable flag
>    b   edit bsd disklabel
>    c   toggle the dos compatibility flag
>    d   delete a partition
>    l   list known partition types
>    m   print this menu
>    n   add a new partition
>    o   create a new empty DOS partition table
>    p   print the partition table
>    q   quit without saving changes
>    s   create a new empty Sun disklabel
>    t   change a partition's system id
>    u   change display/entry units
>    v   verify the partition table
>    w   write table to disk and exit
>    x   extra functionality (experts only)
> 
> Command (m for help): t
> No partition is defined yet!
> 
> Command (m for help): p
> 
> Disk /dev/emcpowera: 700.0 GB, 700079669248 bytes
> 255 heads, 63 sectors/track, 85113 cylinders
> Units = cylinders of 16065 * 512 = 8225280 bytes
> 
>          Device Boot      Start         End      Blocks   Id  System
> 
> Command (m for help): n
> Command action
>    e   extended
>    p   primary partition (1-4)
> p
> Partition number (1-4): 1
> First cylinder (1-85113, default 1): 1
> Last cylinder or +size or +sizeM or +sizeK (1-85113, default 85113): 
> Using default value 85113
> 
> Command (m for help): t
> Selected partition 1
> Hex code (type L to list codes): 8e
> Changed system type of partition 1 to 8e (Linux LVM)
> 
> Command (m for help): p
> 
> Disk /dev/emcpowera: 700.0 GB, 700079669248 bytes
> 255 heads, 63 sectors/track, 85113 cylinders
> Units = cylinders of 16065 * 512 = 8225280 bytes
> 
>          Device Boot      Start         End      Blocks   Id  System
> /dev/emcpowera1               1       85113   683670141   8e  Linux LVM
> 
> Command (m for help): w
> The partition table has been altered!
> 
> Calling ioctl() to re-read partition table.
> Syncing disks.
> [root at bioinformatics ~]# 

All that is good and normal.

> [root at bioinformatics ~]# pvcreate /dev/emcpowera
>   Physical volume "/dev/emcpowera" successfully created
> 
>  [root at bioinformatics ~]# vgcreate bio01VG /dev/emcpowera
>   Found duplicate PV XKollgX4GsBzbFyJsK13JS62S3P4b0Vr: using /dev/sdb
> not /dev/emcpowera
>   Found duplicate PV XKollgX4GsBzbFyJsK13JS62S3P4b0Vr: using /dev/sdc
> not /dev/emcpowera
>   Found duplicate PV XKollgX4GsBzbFyJsK13JS62S3P4b0Vr: using /dev/sdb
> not /dev/emcpowera
>   Found duplicate PV XKollgX4GsBzbFyJsK13JS62S3P4b0Vr: using /dev/sdc
> not /dev/emcpowera
>   Found duplicate PV XKollgX4GsBzbFyJsK13JS62S3P4b0Vr: using /dev/sdb
> not /dev/emcpowera
>   Found duplicate PV XKollgX4GsBzbFyJsK13JS62S3P4b0Vr: using /dev/sdc
> not /dev/emcpowera
>   Volume group "bio01VG" successfully created

Okay, now I'm not sure what is going on.  It is more common for linux
to identify the drives as /dev/sda, /dev/sdb, etc. rather than
/dev/emcpowera.  What might be more useful would be to run

  fdisk -l # That's ell as in list.

and see what drives show up.  Is it possible that /dev/emcpowera is
the physical SAN disk(s) and that /dev/sdb and /dev/sdc are the
virtual disks created by the SAN?  If so, the latter should be
partitioned and pvcreated.

Also note that you created the partition and then ignored it.  Had you
used the partition, it would have been called /dev/emcpowera1 when you
ran pvcreate.

Rick Stevens, feel free to jump in here.  I'm operating from very
recent and limited experience with a SAN.

> [root at bioinformatics ~]# vgdisplay bio01VG
>   Found duplicate PV XKollgX4GsBzbFyJsK13JS62S3P4b0Vr: using /dev/sdb
> not /dev/emcpowera
>   Found duplicate PV XKollgX4GsBzbFyJsK13JS62S3P4b0Vr: using /dev/sdc
> not /dev/emcpowera
>   Found duplicate PV XKollgX4GsBzbFyJsK13JS62S3P4b0Vr: using /dev/sdb
> not /dev/emcpowera
>   Found duplicate PV XKollgX4GsBzbFyJsK13JS62S3P4b0Vr: using /dev/sdc
> not /dev/emcpowera
>   Volume group "bio01VG" doesn't exist
> 
> [root at bioinformatics ~]# vgchange -a y bio01VG
>   Found duplicate PV XKollgX4GsBzbFyJsK13JS62S3P4b0Vr: using /dev/sdb
> not /dev/emcpowera
>   Found duplicate PV XKollgX4GsBzbFyJsK13JS62S3P4b0Vr: using /dev/sdc
> not /dev/emcpowera
>   Found duplicate PV XKollgX4GsBzbFyJsK13JS62S3P4b0Vr: using /dev/sdb
> not /dev/emcpowera
>   Found duplicate PV XKollgX4GsBzbFyJsK13JS62S3P4b0Vr: using /dev/sdc
> not /dev/emcpowera
>   Unable to find volume group "bio01VG"

Cheers,
-- 
Bob McClure, Jr.             Bobcat Open Systems, Inc.
bob at bobcatos.com             http://www.bobcatos.com
The best things in life aren't things.