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Author Copy disk drive to another. Mirroring
Tom

2007-04-20, 1:24 pm

Hi
1-What is the difference between copying a disk to another by the
command "dd" or using any script and the "mirroring" with VxVM.
2-I have 6 servers with the same configuration [ solaris 8, sparc sun
fire, VxVM,SunCluster, 4 disks]. I want to install just one server
and copy all the disks to the other servers [ the boot disk and the
other disks].
3-Is there any difference beween copying the boot disk or copying the
other disks?
4-What about the DIDs and disk labels, will they missed up ?
Thanks

Dave Hinz

2007-04-20, 1:24 pm

On 20 Apr 2007 09:52:13 -0700, Tom <taha25@gmail.com> wrote:
> Hi
> 1-What is the difference between copying a disk to another by the
> command "dd" or using any script and the "mirroring" with VxVM.


Sounds like homework?

Darren Dunham

2007-04-20, 7:17 pm

In comp.unix.solaris Tom <taha25@gmail.com> wrote:
> Hi
> 1-What is the difference between copying a disk to another by the
> command "dd" or using any script and the "mirroring" with VxVM.


If the disk is not in use, nothing.

'dd' copies a block as it exists at that point in time. If the
filesystem is in use then the target may not represent the state of the
source filesystem that existed at any point in time.

> 2-I have 6 servers with the same configuration [ solaris 8, sparc sun
> fire, VxVM,SunCluster, 4 disks]. I want to install just one server
> and copy all the disks to the other servers [ the boot disk and the
> other disks].
> 3-Is there any difference beween copying the boot disk or copying the
> other disks?
> 4-What about the DIDs and disk labels, will they missed up ?
> Thanks


If VxVM is already installed, you do not want to use 'dd' to copy disks
without fully understanding how VxVM stores ids in the private region.
If those ids are no longer unique, "bad things"(TM) can happen

--
Darren Dunham ddunham@taos.com
Senior Technical Consultant TAOS http://www.taos.com/
Got some Dr Pepper? San Francisco, CA bay area
< This line left intentionally blank to confuse you. >
omi61

2007-04-21, 7:16 am

On 20 Apr., 18:52, Tom <tah...@gmail.com> wrote:

> 2-I have 6 servers with the same configuration [ solaris 8, sparc sun
> fire, VxVM,SunCluster, 4 disks]. I want to install just one server
> and copy all the disks to the other servers [ the boot disk and the
> other disks].


Solaris flash installation




Doug Freyburger

2007-04-21, 7:18 pm

Tom <tah...@gmail.com> wrote:
>
> 1-What is the difference between copying a disk to another by the
> command "dd" or using any script and the "mirroring" with VxVM.


1) Which layer the copy is done at and hence the relative priority
as it runs. 2) One gives a static snapshot as the blocks are
read the other keeps track of changed blocks and stays in sync.

> 2-I have 6 servers with the same configuration [ solaris 8, sparc sun
> fire, VxVM,SunCluster, 4 disks]. I want to install just one server
> and copy all the disks to the other servers [ the boot disk and the
> other disks].


I have installed large numbers of workstations using dd to
clone them quickly. Know which files under /etc to change
per host before plugging it into the network.

> 3-Is there any difference beween copying the boot disk or copying the
> other disks?


Depends on the exact OS whether the boot block needs special
treatment. On Solaris and Irix dd handles it correctly as
long as you chose the correct device handles.

> 4-What about the DIDs and disk labels, will they missed up ?


If the drives are not identical, probably.

Also, there exist filesystem formats that can't be copied with
dd. Tru64's AdvFS has this problem. I am not aware of any
Solaris issue like this but I haven't looked into the new ZFS
yet.

BIT

2007-04-23, 1:23 pm

use "ufsdump" command rather than "dd"

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