I think these values may be too high but you should let AIX
support make this decision. I believe you should open a pmr with IBM AIX
support for this.

In the past, when customers have reported these errors, various things have
had to be done in order to change these values. First of all, it will
require TSM to be temporarily brought down. I would try the following
sequence if you wish to proceed - but I would call AIX support first.

        1.See if you can change the values after you unmount the
filesystem. If not, proceed to step 2.
        2.Do a varyoffvg command for the volume group containing the volume.
        3. You now should be able to change the queue depth and
max_coalsece values.
        4. Do a varyonvg for the volume group.
        5. do a mount -a to remount the filesystems.
        6. Retry the dsmfmt command.


At 09:08 AM 1/16/2003 -0500, you wrote:

These values are actually higher than you suggested.

1.  queue depth is set to 48 versus computed value of 45.
2.  max_coalesce is set to x10000 versus computed xF0000

Does it matter that the values are higher ?

Also, when we tried to lower them, we did get the "drive is busy" message
so I am open to your suggestions !!!






Dave Canan <ddcanan AT ATTGLOBAL DOT NET>
Sent by: "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>
01/15/2003 08:41 PM
Please respond to "ADSM: Dist Stor Manager"


        To:     ADSM-L AT VM.MARIST DOT EDU
        cc:
        Subject:        Re: Problems with TSM AIX server V5.1.5.4


Can you do the following and re-post with what you have set for the
following?

smitty devices -> SSA disks -> SSA Logical Disks -> Change/Show
Characteristics of an SSA Logical Disk -> select hdiskxx (where xx is the
hdisk where you are defining the volume)

Look at the following fields:

         1. queue depth.      This should be set to (# of disks in
array-1)*3

         2. max_coalesce   This should be set to (# of disks in array
-1)*65536, converted to hex.

You may have trouble setting these devices  - they may report "device is
busy" if you try and change them. If so, re-post and I'll suggest ways to
get around this. We had one customer report numerous errors like this and
after changing these values, the errors went away.


At 03:58 PM 1/15/2003 -0500, you wrote:
>Just tried formatting a new storage pool volume on the above system.
First
>time since upgrading to 5.1.5.x.
>
>Seeing lots of errors:  LVDD LVM_IO_FAIL is the message.
>
>Nothing in ERRPT but these errors. Nothing to point to a specific
hardware
>failure. Physically checked the drives (SSA) and can see any physical
>indication of problems.
>
>Tried searching IBMLINK with no success.
>
>
>Anyone else seen this ?

Dave Canan
TSM Performance
IBM Advanced Technical Support
ddcanan AT us.ibm DOT com

Dave Canan
TSM Performance
IBM Advanced Technical Support
ddcanan AT us.ibm DOT com