Re: Latest best-practice for reclaim storage

On 15-Jul-2011 02:01 , Holger Scherer wrote:

My experience of several hundreds of system changes on our own
systems and customer systems:

If you change hardware and do a save21, do a RCLSTG before.

Had several times troubles with save21 tapes where the system saved
damaged objects (even if the system should check them at save time)
and ran in trouble later at restore time.

Starting with V5 there seem to be some internal changes which will
rise up only at restore time - or even later.

SAVLIB\SAVOBJ will not save any objects with either partial or full damage, and will terminate when either type of damage is detected. The scenarios described as giving difficulties during restore were most likely to have originated as "logical damage" scenarios. Those issues may have originated from [lack of] conversions or any other various defects; sometimes very specific to object conversions. The restore difficulties were very unlikely to be related to the actual "physical damage" cases. That the RCLSTG may effect many of the conversions and may even correct some limited variety of logical damage, thus making the reclaim appear to have been preventive to some defects that arose, the reclaim can not be concluded to have been generally preventive to the defects which may persist even if the reclaim was performed or have been prevented by any other means that effected conversions that were preventive to the later restore.

Each specific scenario encountered for what was described in the quoted message as "damaged objects" would likely need to be attributed to the specific defect as origin to be generally useful to a reader, since again, most often the "damage" was not physical; i.e. alluding that save-21 is not generally safe without first having performed RCLSTG is unnecessarily casting FUD.

Regards, Chuck