Any administrator can query for information about a storage pool by viewing a standard or a detailed report. Use these reports to monitor storage pool usage, including:
To request a standard report that shows all storage pools defined to the system, enter:
query stgpool
Figure 23 shows a standard report with all storage pools defined to the system. To monitor the use of storage pool space, review the Estimated Capacity and %Util columns.
Figure 23. Information about Storage Pools
+--------------------------------------------------------------------------------+ |Storage Device Estimated %Util %Migr High Low Next | |Pool Name Class Name Capacity Mig% Mig% Storage | | (MB) Pool | |----------- ---------- ---------- ----- ----- ---- ---- ----------- | |ARCHIVEPOOL DISK 0.0 0.0 0.0 90 70 | |BACKTAPE TAPE 180.0 85.0 100.0 90 70 | |BACKUPPOOL DISK 80.0 51.6 51.6 50 30 BACKTAPE | |COPYPOOL TAPE 300.0 42.0 | |ENGBACK1 DISK 0.0 0.0 0.0 85 40 BACKTAPE | | | +--------------------------------------------------------------------------------+
For disk storage pools, this value reflects the total amount of available space in the storage pool, including any volumes that are varied offline.
For sequential access storage pools, this value is an estimate of the total amount of available space on all volumes in the storage pool. The total includes volumes that have unavailable, read-only, offsite, or destroyed access mode, and all scratch volumes that can be acquired in this storage pool. Volumes in a sequential access storage pool, unlike those in a disk storage pool, do not contain preallocated space. Data is written to a volume as necessary until the end of the volume is reached. For this reason, the estimated capacity is truly an estimate of the amount of available space in a sequential access storage pool.
For disk storage pools, this value reflects the total number of disk blocks currently allocated by ADSM. Space is allocated for backed-up, archived, or space-managed files that are eligible for server migration, cached files that are copies of server-migrated files, and files that reside on any volumes that are varied offline.
| Note: | The value for %Util can be higher than the value for %Migr if you query for storage pool information while a client transaction (such as a backup) is in progress. The value for %Util is determined by the amount of space actually allocated (while the transaction is in progress). The value for %Migr only represents the space occupied by committed files. At the end of the transaction, %Util and %Migr become synchronized. |
For sequential access storage pools, this value is the percentage of the total bytes of storage available that are currently being used to store active data (data that is not expired). Because the server can only estimate the available capacity of a sequential access storage pool, this percentage also reflects an estimate of the actual utilization of the storage pool.
Figure 23 shows that the estimated capacity for a disk storage pool named BACKUPPOOL is 80MB, which is the amount of available space on disk storage. More than half (51.6%) of the available space is occupied by either backup files or cached copies of backup files.
The estimated capacity for the tape storage pool named BACKTAPE is 180MB, which is the total estimated space available on all tape volumes in the storage pool. This report shows that 85% of the estimated space is currently being used to store workstation files.
| Note: | This report also shows that volumes have not yet been defined to the ENGBACK1 storage pool, because the storage pool shows an estimated capacity of 0.0MB. |
Four fields on the standard storage pool report provide you with information about the migration process. They include:
For disk storage pools, this value represents the amount of disk space occupied by backed-up, archived, or space-managed files that can be migrated to another storage pool, including files on volumes that are varied offline. Cached data are excluded in the %Migr value.
For sequential access storage pools, this value is the percentage of the total volumes in the storage pool that actually contain data at the moment. For example, assume a storage pool has four explicitly defined volumes, and a maximum scratch value of six volumes. If only two volumes actually contain data at the moment, then %Migr will be 20%.
This field is blank for copy storage pools.
Figure 23 shows that the migration thresholds for BACKUPPOOL storage pool are set to 50% for the high migration threshold and 30% for the low migration threshold.
When the amount of migratable data stored in the BACKUPPOOL storage pool reaches 50%, the server can begin to migrate files to BACKTAPE.
To monitor the migration of files from BACKUPPOOL to BACKTAPE, enter:
query stgpool back*
See Figure 24 for an example of the results of this command.
If caching is on for a disk storage pool and files are migrated, the %Util value does not change because the cached files still occupy space in the disk pool. However, the %Migr value decreases because the space occupied by cached files is no longer migratable.
Figure 24. Information on Backup Storage Pools
+--------------------------------------------------------------------------------+ |Storage Device Estimated %Util %Migr High Low Next | |Pool Name Class Name Capacity Mig% Mig% Storage | | (MB) Pool | |----------- ---------- ---------- ----- ----- ---- ---- ----------- | |BACKTAPE TAPE 180.0 95.2 100.0 90 70 | |BACKUPPOOL DISK 80.0 51.6 28.8 50 30 BACKTAPE | | | +--------------------------------------------------------------------------------+
You can query the server to monitor the migration process by entering:
query process
A message similar to Figure 25 is displayed:
Figure 25. Information on the Migration Process
+--------------------------------------------------------------------------------+ | Process Process Description Status | | Number | |-------- ------------------------ --------------------------------------------- | | 2 Migration Disk Storage Pool BACKUPPOOL, Moved Files: | | 1086, Moved Bytes: 25555579, Unreadable | | Files: 0, Unreadable Bytes: 0 | | | +--------------------------------------------------------------------------------+
When migration is finished, the server displays the following message:
+--------------------------------------------------------------------------------+ |ANR1101I Migration ended for storage pool BACKUPPOOL. | +--------------------------------------------------------------------------------+
A problem can occur during the migration process that causes the migration process to be suspended. For example, there may not be sufficient space in the storage pool to which data is being migrated. When migration is suspended, the process might be retried.
At this point, a system administrator can:
The server attempts to restart the migration process every 60 seconds for several minutes and then will terminate the migration process.
To stop server migration when a problem occurs or when you need the resources the process is using, you can cancel the migration.
First determine the identification number of the migration process by entering:
query process
A message similar to Figure 26 is displayed:
Figure 26. Getting the Identification Number of the Migration Process
+--------------------------------------------------------------------------------+ | Process Process Description Status | | Number | |-------- ------------------------ --------------------------------------------- | | 1 Migration ANR1113W Migration suspended for storage pool | | BACKUPPOOL - insufficient space in | | subordinate storage pool. | +--------------------------------------------------------------------------------+
Then you can cancel the migration process by entering:
cancel process 1
Some errors cause the server to continue attempting to restart the migration process after 60 seconds. (If the problem still exists after several minutes, the migration process will end.) To stop the repeated attempts at restart, you can change some characteristics of the storage pool from which data is being migrated. Depending on your environment, you can:
In the example in "Example: Monitoring the Migration of Data Between Storage Pools", you could update the disk storage pool BACKUPPOOL.
In the example in "Example: Monitoring the Migration of Data Between Storage Pools", you could add volumes to the disk storage pool BACKUPPOOL to increase its storage capacity.
| Note: | Do this only if you received an out-of-space message for the storage pool to which data is being migrated. |
A migration process can be suspended because of insufficient space in the storage pool to which data is being migrated. To allow the migration process to complete, you can provide additional storage volumes for that storage pool.
In the example in "Example: Monitoring the Migration of Data Between Storage Pools", you could add volumes to the BACKTAPE storage pool or increase the maximum number of scratch tapes allowed for it. Either way, you increase the storage capacity of BACKTAPE.
The %Util value includes cached data on a volume (when cache is enabled) and the %Migr value excludes cached data. Therefore, when cache is enabled and migration occurs, the %Migr value decreases while the %Util value remains the same. The %Util value remains the same because the migrated data remains on the volume as cached data. In this case, the %Util value only decreases when the cached data expires.
If you update a storage pool from CACHE=YES to CACHE=NO, the cached files will not disappear immediately. The %Util value will be unchanged. The cache space will be reclaimed over time as the server needs the space, and no additional cached files will be created.
To determine whether cache is being used on disk storage and to monitor how much space is being used by cached copies, query the server for a detailed storage pool report. For example, to request a detailed report for BACKUPPOOL, enter:
query stgpool backuppool format=detailed
Figure 27 displays a detailed report for the storage pool.
Figure 27. Detailed Storage Pool Report
+--------------------------------------------------------------------------------+ | Storage Pool Name: BACKUPPOOL | | Storage Pool Type: PRIMARY | | Device Class Name: DISK | | Estimated Capacity (MB): 80.0 | | Pct Util: 42.0 | | Pct Migr: 29.6 | | Pct Logical: 82.1 | | High Mig Pct: 50 | | Low Mig Pct: 30 | | Migration Processes: | | Next Storage Pool: BACKTAPE | | Reclaim Storage Pool: | | Maximum Size Threshold: No Limit | | Access: Read/Write | | Description: | | Overflow Location: | | Cache Migrated Files?: Yes | | Collocate?: | | Reclamation Threshold: | | Maximum Scratch Volumes Allowed: | | Delay Period for Volume Reuse: 0 Day(s) | | Migration in Progress?: Yes | | Amount Migrated (MB): 0.10 | |Elapsed Migration Time (seconds): 5 | | Reclamation in Progress?: | | Volume Being Migrated/Reclaimed: | | Last Update by (administrator): SERVER_CONSOLE | | Last Update Date/Time: 04/07/1997 16:47:49 | | | +--------------------------------------------------------------------------------+
When Cache Migrated Files? is set to yes, the value for %Util should not change because of migration, because cached copies of files migrated to the next storage pool remain in disk storage.
This example shows that utilization remains at 42%, even after files have been migrated to the BACKTAPE storage pool, and the current amount of data eligible for migration is 29.6%.
When Cache Migrated Files? is set to no, the value for %Util more closely matches the value for %Migr because cached copies are not retained in disk storage.
| Task | Required Privilege Class |
|---|---|
| Query the server for information about server storage | Any administrator |
Any administrator can request information about server storage occupancy. Use the QUERY OCCUPANCY command for reports with information broken out by node or file space. Use this report to determine the amount of space used by:
Each report gives two measures of the space in use by a storage pool:
The amount of space used for logical files. A logical file is a client file. A logical file is stored either as a single physical file, or in an aggregate with other logical files.
The amount of space used for physical files. A physical file is either a single logical file, or an aggregate file composed of logical files.
An aggregate file may contain empty space that had been used by logical files that are now expired or deleted. Therefore, the amount of space used by physical files is equal to or greater than the space used by logical files. The difference gives you a measure of how much unused space any aggregate files may have. The unused space can be reclaimed in sequential storage pools.
You can also use this report to evaluate the average size of workstation files stored in server storage.
Any administrator can request information about the space used by each client node and file space:
To determine the amount of server storage space used by the /home file space belonging to the client node MIKE, for example, enter:
query occupancy mike /home
Remember that file space names are case-sensitive and must be entered exactly as they are known to the server. Use the QUERY FILESPACE command to determine the correct capitalization. For more information, see "Requesting Information about File Spaces".
Figure 28 shows the results of the query. The report shows the number of files backed up, archived, or migrated from the /home file space belonging to MIKE. The report also shows how much space is occupied in each storage pool.
If you back up the ENGBACK1 storage pool to a copy storage pool, the copy storage pool would also be listed in the report. To determine how many of the client node's files in the primary storage pool have been backed up to a copy storage pool, compare the number of files in each pool type for the client node.
Figure 28. A Report of the Occupancy of Storage Pools by Client Node
+--------------------------------------------------------------------------------+ | Physical Logical| |Node Name Type Filespace Storage Number of Space Space| | Name Pool Name Files Occupied Occupied| | (MB) (MB)| |--------------- ---- ----------- ----------- --------- ---------- --------| |MIKE Bkup /home ENGBACK1 513 3.52 3.01| +--------------------------------------------------------------------------------+
You can monitor the amount of space being used by an individual storage pool, a group of storage pools, or storage pools categorized by a particular device class. Creating occupancy reports on a regular basis can help you with capacity planning.
To query the server for the amount of data stored in backup tape storage pools belonging to the TAPECLASS device class, for example, enter:
query occupancy devclass=tapeclass
Figure 29 displays a report on the occupancy of tape storage pools assigned to the TAPECLASS device class.
Figure 29. A Report on the Occupancy of Storage Pools by Device Class
+--------------------------------------------------------------------------------+ |Node Name Type Filespace Storage Number of Physical Logical| | Name Pool Name Files Space Space| | Occupied Occupied| | (MB) (MB)| |--------------- ---- ----------- ----------- --------- ---------- --------| |CAROL Arch OS2C ARCHTAPE 5 .92 .89| |CAROL Bkup OS2C BACKTAPE 21 1.02 1.02| |PEASE Arch /home/peas- ARCHTAPE 492 18.40 18.40| | e/dir | |PEASE Bkup /home/peas- BACKTAPE 33 7.60 7.38| | e/dir | |PEASE Bkup /home/peas- BACKTAPE 2 .80 .80| | e/dir1 | |TOMC Arch /home/tomc ARCHTAPE 573 20.85 19.27| | /driver5 | |TOMC Bkup /home BACKTAPE 13 2.02 1.88| +--------------------------------------------------------------------------------+
| Note: | For archived data, you may see "(archive)" in the Filespace Name column instead of a file space name. This means that the data was archived before collocation by file space was supported by the server. |
You can query the server for the amount of space used by backed-up, archived, and space-managed files. By determining the average size of workstation files stored in server storage, you can estimate how much storage capacity you might need when registering new client nodes to the server. See "Estimating Space Needs for Storage Pools" and "Estimating Space for Archived Files in a Random Access Storage Pool" for information about planning storage space.
To request a report about backup versions stored in the disk storage pool named BACKUPPOOL, for example, enter:
query occupancy stgpool=backuppool type=backup
Figure 30 displays a report on the amount of server storage used for backed-up files.
Figure 30. A Report of the Occupancy of Backed-Up Files in Storage Pools
+--------------------------------------------------------------------------------+ |Node Name Type Filespace Storage Number of Physical Logical| | Name Pool Name Files Space Space| | Occupied Occupied| | (MB) (MB)| |--------------- ---- ----------- ----------- --------- ---------- --------| |CAROL Bkup OS2C BACKUPPOOL 513 23.52 23.52| |CAROL Bkup OS2D BACKUPPOOL 573 20.85 20.85| |PEASE Bkup /marketing BACKUPPOOL 132 12.90 9.01| |PEASE Bkup /business BACKUPPOOL 365 13.68 6.18| |TOMC Bkup / BACKUPPOOL 177 21.27 21.27| +--------------------------------------------------------------------------------+
To determine the average size of backup versions stored in BACKUPPOOL, complete the following steps using the data provided in Figure 30:
In this example, backup versions occupy 92.22MB of space in BACKUPPOOL.
In this example, 1760 backup versions reside in BACKUPPOOL.
In this example, the average size of each workstation file backed up to BACKUPPOOL is about 0.05MB, or approximately 50KB.
You can use this average to estimate the capacity required for additional storage pools that are defined to ADSM.