Re: Multiple sessions per tape

Using  a disk pool in between has some advantages: first of all if you want
to backup clients directly to tape you can run a number of sessions that
cannot be bigger  than the number of available tape drives; furthermore
using disks you have the possibility to exploit the disk throughput that is
bigger than the tape one.
The advantage is particurarly higher as much as the files are smaller,
while it decrease when backing up the bigger files (like DBs files for
example).

Cordiali saluti / Best regards

Gianluca Perilli

EMEA Support, GlobalResponseTeam Storage
e-mail: gianluca_perilli AT it.ibm DOT com

Tivoli Software, IBM Software Group

Via Sciangai 53, Rome 00144            Italy
Office : +39.06.59664581
Mobile: +39.335.7840985
Fax:      +39.06.59662077






                      "Conko, Steven"
                      <sconko AT ADT DOT COM>         To:       ADSM-L AT 
VM.MARIST DOT EDU
                      Sent by: "ADSM:          cc:
                      Dist Stor                Subject:  Re: Multiple sessions 
per tape
                      Manager"
                      <[email protected]
                      .EDU>


                      31-10-02 14.33
                      Please respond to
                      "ADSM: Dist Stor
                      Manager"





why does having the diskpool in between improve performance?

-----Original Message-----
From: Alexander Lazarevich [mailto:alazarev AT HERA.ITG.UIUC DOT EDU]
Sent: Wednesday, October 30, 2002 4:35 PM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Re: Multiple sessions per tape


Totally. We used to backup to tape. But since putting a disk spool
inbetween, the performance has significantly improved.

Alex
---                                                        ---
   Alex Lazarevich | Systems | Imaging Technology Group
   alazarev AT itg.uiuc DOT edu | (217)244-1565 | www.itg.uiuc.edu
---                                                        ---


On Wed, 30 Oct 2002, Joshua Bassi wrote:

> It is restricted to one.  The best way to backup your data is to a disk
> pool first, then bleed the diskpool to tape and you will get much better
> performance out of your single session than you would if you backed up
> directly to tape.
>
>
> --
> Joshua S. Bassi
> IBM Certified - AIX 4/5L, SAN, Shark
> Tivoli Certified Consultant - ADSM/TSM
> eServer Systems Expert -pSeries HACMP
>
> AIX, HACMP, Storage, TSM Consultant
> Cell (831) 595-3962
> jbassi AT ihwy DOT com
>
>
> -----Original Message-----
> From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf 
> Of
> Conko, Steven
> Sent: Wednesday, October 30, 2002 10:16 AM
> To: ADSM-L AT VM.MARIST DOT EDU
> Subject: Multiple sessions per tape
>
> We're running ADSM 4.2 on AIX 4.3.3, 3494 library, 3590 drives.
>
> Is there any way to control the number of sessions per tape or is it
> restricted to one?
>
> Steven A. Conko
> Senior Unix Systems Administrator
> ADT Security Services, Inc.
>