Hello,

I may be installing a new DB2 v. 9.7 Enterprise Edition (64 bit) on a 
Linux server soon. The database will contain around 10TB of data once 
it's fully loaded. We will not be using data compression (too expensive).

We have previously used non-automatic (DMS) storage (and even raw 
devices, to a certain degree), but I would very much like to cut down on 
administration; so in the new database installation, I'd like to use 
automatic storage.

The DBMS will be using data living on an IBM XIV storage system. The 
philosophy of XIV system is that you cannot specify the placement of 
data; in return, the storage system is responsible for distributing data 
in little chunks all over the (many) available disks (maintaining copies 
of the chunks on separate disks, so that a disk crash will not bring it 
all down).

I can't seem to find any disadvantages of automatic storage, especially 
because it's meaningless to create several different LUNs on on XIV 
system (the LUNs share all the disks anyway).

Am I overlooking drawbacks involved with automatic storage? Does 
automatic storage prevent features like a database rebuild (step-wise 
restores), for example? Or does it somehow introduce a higher risk of 
locking (during backups), like it's the case with SMS tablespaces 
containing BLOBs?

-- 
Troels

On 1=D4=C228=C8=D5, =C9=CF=CE=E73=CA=B141=B7=D6, Troels Arvin <tro...@arvin=
..dk> wrote:
> Hello,
>
> I may be installing a new DB2 v. 9.7 Enterprise Edition (64 bit) on a
> Linux server soon. The database will contain around 10TB of data once
> it's fully loaded. We will not be using data compression (too expensive).
>
> We have previously used non-automatic (DMS) storage (and even raw
> devices, to a certain degree), but I would very much like to cut down on
> administration; so in the new database installation, I'd like to use
> automatic storage.
>
> The DBMS will be using data living on an IBM XIV storage system. The
> philosophy of XIV system is that you cannot specify the placement of
> data; in return, the storage system is responsible for distributing data
> in little chunks all over the (many) available disks (maintaining copies
> of the chunks on separate disks, so that a disk crash will not bring it
> all down).
>
> I can't seem to find any disadvantages of automatic storage, especially
> because it's meaningless to create several different LUNs on on XIV
> system (the LUNs share all the disks anyway).
>
> Am I overlooking drawbacks involved with automatic storage? Does
> automatic storage prevent features like a database rebuild (step-wise
> restores), for example? Or does it somehow introduce a higher risk of
> locking (during backups), like it's the case with SMS tablespaces
> containing BLOBs?
>
> --
> Troels


it is meaningful for less sized database with less management cost.
for a 10T database, I trust more on DMS than AMS. Just personal view,
I don't have test data.