Raghu,

as you wrote it was already discussed on this list. In last thread we with
Paul confirmed both that ESS is a different beast. Very, very deep under
the covers of ESS there are really RAID-5 arrays. But the addtional layers
on top of them is making ESS better than nearly all RAID-1
implementations.
Data taken from ESS manuals - ESS is capable to feed the data at .... 1280
MB/s (yes, one 1,28 gigabytes per second) !!! And with new 800 model it is
even better.
So answer again is "it depends". Not all RAID-5 are created equal.
If you can afford ESS this is (IMO) the best answer for TSM.

Zlatko Krastev
IT Consultant






Raghu S <raghu AT COSMOS.DCMDS.CO DOT IN>
Sent by: "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>
23.10.2002 07:30
Please respond to "ADSM: Dist Stor Manager"


        To:     ADSM-L AT VM.MARIST DOT EDU
        cc:
        Subject:        Re: RAID5 in TSM


Paul,


keeping TSM database,log and disk storage pool on RAID5 degrades the
performance???

Regards

Raghu



                    "Seay, Paul"
                    <seay_pd@NAPT        To:     ADSM-L AT VM.MARIST DOT EDU
                    HEON.COM>            cc:
                    Sent by:             Subject:     Re: RAID5 in TSM
                    "ADSM: Dist
                    Stor Manager"
                    <ADSM-L AT VM DOT MA
                    RIST.EDU>


                    10/22/2002
                    06:29 AM
                    Please
                    respond to
                    "ADSM: Dist
                    Stor Manager"





Are you running compression?

Paul D. Seay, Jr.
Technical Specialist
Naptheon Inc.
757-688-8180


-----Original Message-----
From: Raghu S [mailto:raghu AT COSMOS.DCMDS.CO DOT IN]
Sent: Tuesday, October 22, 2002 8:03 AM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: RAID5 in TSM


Hi,

There was a lot of discussion on this topic before.But i am requesting TSM
gurus give their comments again.

The set up is like this.

TSM Server : Windows NT 4.0 SP6, TSM 5.1.0.0

                            392 MB memory, P III

                  Adaptech Ultra SCSI

                Hard Disk :  Internal   Hardware RAID 5:

                         array A : 8.678GB * 3 : 17.356GB data and 8.678
GB
parity

                         array B : 35.003 GB * 3 : 70.006GB data and
35.003
GB parity.


Both array A and array B are connected to the same channel.

OS and TSM 5.1 are installed on array A

TSM data base, recovery log and Disk storage pool are installed in array
B.

Database : 2GB+2GB = 4 GB  and mirrored at TSM level on the same array

Recovery Log : 500MB + 500 MB = 1 GB and mirrored at TSM level on the same
array

Disk Storage pool : 10GB+10GB+10GB+10GB+5GB=45GB on array B


TSM client: 4.1.2.12 ( Tivoli says 4.1.2.12 is not supported with 5.1
Server. But i could take the backup,archive and restore with this
combination )

Number of Clients : 55, all are windows

Incremental backup : 1GB/ client/day.

backup window : 9AM to 6PM with 50% randamization ( all are in polling
mode
)

LAN : 100Mbps

End of the day only 10 clients could finish the backup.Remaining all are
missing or "?" ( in progress ) or failed.

Through the entire backup window the CPU load is 100% with dsmsvc.exe
holding 98%

I tested with various options. I stopped the schedular and fired 3 clients
backup manually at the same time.Each client has 1 GB of incremental data.
It took three hours to finish the backup. While backing up i observed
there
was lot of idletime outs of sessions.

Network choke is not there. I checked this with FTP.

Whats the bottleneck here? Is RAID 5 is creating problems ( DB,log and
storage pool all are on the RAID 5 )? I asked the customer to arrange a
testing machine without any RAID. I will be getting that in two
days.Before
going on to the testing i like to know your comments on this.



Regards

Raghu S Nivas
Consultant - TSM
DCM Data Systems Ltd
New Delhi
India.