RE: Reclaim storage

1.      How long will it take?

        The only way that I know of to estimate the time needed for a
Reclaim Storage is to use the time from a previous RCLSTG on the same
system.  If you have never done one on this box this is impossible,
however as a general rule a faster box should run faster if the
environment is essentially similar.  In general the time is primarily
dependant on the number of objects on the system (and this includes IFS
objects!)  In ancient times it was considered to be a good practice to
run RCLSTG prior to a release upgrade, but this is no longer the case.
Often, the RCLSTG *DBXREF command may be all that is needed.  Our horror
story:  Our 720 took 12 hours to run a full RCLSTG, after upgrading to
an 810 the full RCLSTG took about 4 hours.  After deciding to add
external storage (fiber-atteched shark DASD in a user ASP) and keep more
of our documents (8 M and counting, in the IFS) online the next RCLSTG
had to be killed after 48 hours and we have never attempted another.

2.      What the heck is a reclaim storage? 

-- RCLSTG addresses each object and then validates the headers and
pointers for that object.
-- Finds orphaned objects.
-- Corrects, where possible, objects that were incompletely updated (for
example, database files, libraries, device descriptions, directories and
stream files) and user profiles containing incorrectly recorded object
ownership information.
-- Deletes any unusable objects or fragments.

The RCLSTG command reclaims all objects secured by an authorization list
that are damaged or destroyed and assigns the objects to the
authorization list QRCLAUTL.

Overview of the RCLSTG Command:
http://www-912.ibm.com/s_dir/slkbase.nsf/1ac66549a21402188625680b0002037
e/9373303619fb4b89862565c2007d4bcf?OpenDocument&Highlight=0,rclstg

The bottom line?  The RCLSTG command should not be run unless there is a
warranted reason (e.g. IBM support told you to.) for running the
command. 

Regards,
 
Scott Ingvaldson
System i Administrator
GuideOne Mutual Insurance Company


-----Original Message-----
date: Wed, 3 Jan 2007 08:27:56 -0500
from: "Dave Snyder" <Dsnyder@xxxxxxxxxx>
subject: Reclaim storage

The renewed discussion of performing a reclaim storage reminds me that
we have never run one on our 520 that we have been on since Oct 2005. I
have an upcoming weekend where we will need to bring the system down to
add some memory and also install some third-party software that requires
us to be in a restricted state. Since we are down for those occurrences
it would be wise for me to take advantage of the time and also run the
reclaim storage, since down time is at a premium these days.

 

When I bring this up to management as a proposal I know I will get two
questions:

 

1.      How long will it take?
2.      What the heck is a reclaim storage?

 

I know what it took when we were on an 820 (2 ? hours in Feb 2004), but
now being on a 520 (2400cpw) with more dasd (808gig / 65% utilization)
and memory (4gig), and new release (v5r3), I am not sure of an estimate.
Has anyone done one with conditions close to these that might be able to
share some time estimates? I am not having any problems or receiving any
messages that I am aware of, but if I do not take advantage of this
window to do one now it might come back to bite me. 

 

For the second question, how do you explain it to non-technical
management people? What Windows function can I relate it to that they
might understand? It is not a disk defrag, maybe a scan or cleanup?

 

Thanks.

Dave