Use the PAGEDEL command to delete, replace, or drain (quiesce)
local page data sets.
Attention: Use this command only at the request of your
system programmer. Misuse can seriously impair system performance.
This command allows you to remove or replace local page data sets without requiring an IPL.
Note: Draining a data set means freeing its in-use slots. The system
effects this by making the data set read-only.
You might need to delete, replace or drain local
page data sets for any of the following reasons:
- The hardware is being reconfigured.
- The hardware is generating I/O errors.
- The page configuration is being changed.
- System tuning requires the change.
When you replace a local page data set, the system migrates the in-use slots from the old data set to the
new one.
When you delete a page data set, the
system migrates the in-use slots to other data sets before it deletes
the data set. When ASM migrates pages, storage-class memory (SCM) is not
used as part of the auxiliary storage pool. Before ASM migrates pages,
you must ensure that sufficient space is available on other paging
data sets.
The system keeps track of the in-use slots on both the old or deleted
data set and the new data set until the owner references the pages.
Thus, when you issue a PAGEADD command to allocate a new data set,
the system might indicate that some slots on the newly allocated data
set are already in use. As soon as the owner references a page, the
system frees the slot both from the newly allocated data set and from
the data set to which the page was migrated.
Note: - You cannot use PAGEDEL to delete, replace, or drain the PLPA, common, or the last local page data sets.
- When you enter a PAGEDEL command, the system issues a highlighted,
non-rollable message to indicate that the command is accepted. The
message remains on the console screen until the PAGEDEL command completes.
- If you enter a PAGEDEL command while a PAGEDEL command is already
in progress, the system issues a message that it rejects the command.
- The system rejects a PAGEDEL command that decreases the amount
of auxiliary storage below a fixed percentage of the available auxiliary
storage.
- To identify the page data sets the system
is currently using or the status of the PAGEDEL command, issue the
DISPLAY ASM command.
- When issuing the PAGEDEL DELETE command, there is
the potential for significant storage usage. Several blocks of storage
in ESQA are obtained in order to process the PAGEDEL command. This
includes a x'500' byte block for each cylinder on the deleted data
set that contains in-use slots. Some of this storage will remain in
use and not freed until all the in-use slots are freed, which could
be some time after the PAGEDEL has completed (as indicated by message
IEE205I).
If possible, use the PAGEDEL REPLACE option
instead of the DELETE option to avoid the ESQA storage usage associated
with the DELETE option. With the REPLACE option, slots are migrated
from the old data set directly to the new data set without the need
to keep track of the location of the migrated slots (thus eliminating
the need for extra ESQA storage).