CBR3794A Library library-name has entered the out of cache free space critical state.
Explanation
The available cache in library library-name has entered the out-of-cache resource critical state.
TS7700
Virtualization Engine: When the TS7700 Virtualization Engine determines that the
amount of cache space occupied by valid data rises
above threshold, the library enters this state. Prior
to Release 1.7 of the TS7700 (PGA1), the threshold was defined at
95% of the configured cache capacity and starting with that release,
the threshold is now defined at 1 TB below the configured cache capacity.
The disk cache repository referenced is the primary deep disk cache
of the TS7720.
TS7680 ProtecTIER® Deduplication Gateway: When the TS7680 determines that the amount of available cache space reaches a critical level, the library enters this state. This state takes into account the number of jobs (devices) that are writing data to ensure that currently running jobs can complete. At a minimum, this state can also be entered when the amount of free space falls below 500 gigabytes (might be entered sooner based on the number of jobs that are running and the projected cache usage). As the available cache space continues to decline, the TS7680 might also reach a point where it needs to throttle the write activity of currently running jobs resulting in job delays.
System action
Mount operations that have been accepted before
entering this state complete and volumes currently mounted can continue
to perform host I/O operations. Prior to Release
1.7 of the TS7700 and for the TS7680, any scratch mount operations
received while in this state are failed by the library. Any specific
mount operations received in this state are accepted by the library;
however, any write operation to the volume is failed. Starting
with Release 1.7 of the TS7700, distributed libraries that are in
this state will not be chosen as a tape volume cache during scratch
mounts and specific mounts will favor distributed libraries that are
not in this state. If a specific mount is issued to a distributed
library that in this state and a write occurs, the write will be failed.
TS7700 Virtualization Engine: This state is left
when the TS7700 determines that the amount
of cache space occupied by valid data falls below a point that is
2.5 terabytes below the threshold. In addition
to reporting the individual distributed library's state, the composite
state of all of the TS7700 subsystems in the
configuration is also reported. Prior to Release
1.7 of the TS7700, if one or more of the distributed libraries
are in this state, the associated composite library is also in this
state. Starting with Release 1.7 of the TS7700,
the composite library is only in this state if all of the distributed
libraries (with this type of cache) are in this state. Message
CBR3795I is issued when a library has left this state. When this state
is left, CBR4196D provides an opportunity to retry failing mount requests.
TS7680 ProtecTIER Deduplication Gateway: While in this state, the TS7680 can be configured (at install time) to automatically delete data associated with scratch volumes that are in the “grace period”. Volumes with the shortest time remaining in the grace period will be deleted first. This state is left when the TS7680 determines that the amount of available cache space can accommodate the currently running write jobs plus an additional number of jobs. Message CBR3795I is issued when the library has left this state. When this state is left, message CBR4196D provides an opportunity to retry failing mount requests.
Operator response
To make cache space available, copy or remove (return to scratch) older data from the library as appropriate, and respond to any outstanding CBR4196D messages. In addition to this, the TS7680 also attempts to free up cache space by deleting data associated with scratch volumes (see the system action for additional details).
System programmer response
See the operator response.
Source
Object Access Method (OAM)
Routing Code
2,3,5
Descriptor Code
2