--> Cache Hit Pct.: 90.08

David already pointed this is not good for performance.

--> Will this affect performance on the system (swap usage or paging)?

You have to verify how your operating system is tuned, how much memory is
available to applications, are there other applications, etc, etc. This
would be a long story how to squeeze the maximum from your box. But few
basic settings may give you 80+ % of the maximum which probably will be
much better than your current state.

--> Yes, DB volumes are on Veritas filesystem

Several people on this list reported performance problems when DB volumes
were on Veritas. Switch to raw devices gave them noticeable increase.
Others are using VxFS with good performance after some tuning. So you have
two options: fine tune your Veritas filesystems or switch to raw devices.
If you search through list archives for "UFS" or "VxFS" you will find
several discussions on this topic.

Zlatko Krastev
IT Consultant






Luke Dahl <ldahl AT JPL.NASA DOT GOV>
Sent by: "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>
21.11.2002 00:24
Please respond to "ADSM: Dist Stor Manager"


        To:     ADSM-L AT VM.MARIST DOT EDU
        cc:
        Subject:        Re: Database Questions


Output from q db f=d:
          Available Space (MB): 50,012
        Assigned Capacity (MB): 45,012
        Maximum Extension (MB): 5,000
        Maximum Reduction (MB): 10,720
             Page Size (bytes): 4,096
            Total Usable Pages: 11,523,072
                    Used Pages: 7,574,343
                      Pct Util: 65.7
                 Max. Pct Util: 76.2
              Physical Volumes: 51
             Buffer Pool Pages: 10,500
         Total Buffer Requests: 180,673,719
                Cache Hit Pct.: 90.08
               Cache Wait Pct.: 1.74
           Backup in Progress?: Yes
    Type of Backup In Progress: Full
  Incrementals Since Last Full: 0
Changed Since Last Backup (MB): 64.07

BufPoolSize        42000

I increased the bufpoolsize from 37000 to 42000 a few days ago to bring
the
ratio up?  Will this affect performance on the system (swap usage or
paging)?
Yes, DB volumes are on Veritas filesystem...  I can get you the exact
Veritas
levels if it would help...

Thank you very much, I really appreciate the help!

Zlatko Krastev/ACIT wrote:

> You can find long discussions on this topic in the list archives.
> - it is mostly disadvantageous to have more than one or two DB volumes
per
> disk/array - parallelism you create with more volumes results disk heads
> moving back and forth. You are shooting yourself in the leg.
> - RAID 5 is definitely not very good for TSM DB and for average or
> heavy-loaded server might be disastrous for performance. For small
servers
> might be just fine. Your server with 35 GB DB does not fit in second
> category.
> - "sessions running for hours" sounds terrible. What is DB cache hit
> ratio? Do you have DB volumes on Veritas filesystem?!?
>
> Zlatko Krastev
> IT Consultant
>
> Luke Dahl <ldahl AT JPL.NASA DOT GOV>
> Sent by: "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>
> 07.11.2002 19:47
> Please respond to "ADSM: Dist Stor Manager"
>
>
>         To:     ADSM-L AT VM.MARIST DOT EDU
>         cc:
>         Subject:        Database Questions
>
> Does anyone know of any advantage/disadvantage of the file sizes for the
> database?  Is there an advantage to creating many 1Gb .db files over
> fewer 10Gb .db files?  Also, we're running TSM 4.2.1.15 on Solaris 5.8
> using raid 5.  I've heard performance can be much greater with raid 0.
> Any truth to that?  We're seeing load averages above 10 nearly every day
> and TSM performance is pretty poor.  Our database size is 35Gb and
> sessions are running for hours (even small incrementals of various
> workstations).  Network bandwidth hasn't peaked over 50% in any 24 hour
> duration.  Any thoughts?  Many thanks in advance.
>
> Luke Dahl
> NASA - Jet Propulsion Laboratory
> 818-354-7117