9 Partitioning the Library

Library partitioning is an optional feature that divides library resources (drive bays, storage cells, and CAPs) into smaller subsections to allow different hosts to independently use a portion of the library. The library supports up to 16 partitions. Each partition appears as a standalone library to the host, which allows more than one application to use the library simultaneously.

IMPORTANT:

Partitioning now comes standard. However, to use partitioning, you must enable it in the library settings (see "Configure the Library with the Configuration Wizard").

Contents

• Partitioning Guidelines to Maximize Library Performance

• Add a Partition

• Edit the Partition Attributes

• Move Storage Cells and Drive Bays to a Partition

• Delete a Partition

• Assign Partitions to a SCSI Host and Alter LUN Assignment

• View the Host Connections of a Partition

• Place a Partition Online or Offline

• Why is there a Default Partition in a "Non-Partitioned" Library?

• Why is there a Media Validation Partition?

• What Occurs When You Disable Partitioning

See Also

• "Add or Remove Drives from the Media Validation Partition (Pool)"

• "Create a CAP Pool"

• "Assign a CAP Pool to a Partition"

• "Assign Ownership of a Shared CAP to a Partition"

Partitioning Guidelines to Maximize Library Performance

• Partition storage slots in the largest blocks possible. Cluster cartridges and drives together based on workload. Ensure that each partition has an adequate number of data cartridges, scratch cartridges, and tape drives to support peak workload.

• Avoid partitioning individual drives and storage cells. Individually add and remove resources only when you need to fine-tune a partition that has already been broadly defined in larger blocks.

• Install enough CAPs to provide at least one CAP for each partition. This allows each partition to contain a dedicated CAP.

• For quicker enter and ejects, partition storage cells close to the CAPs. For quicker access to stored data, partition storage cells close to the drives.

Add a Partition

1. Click Partitioning in the left navigation area of the GUI.

2. Click Create New Partition .

   Note:

   If the Create New Partition icon is grayed-out , you need to enable partitioning in the library settings (see "Configure the Library with the Configuration Wizard").

3. Enter the partition attributes (see "Partition Attributes" for a description). Click Ok to create the partition.

4. A newly created partition does not have any resources assigned to it. To allocate resources, see "Move Storage Cells and Drive Bays to a Partition".

Partition Attributes

You can set the partition attributes when adding or modifying a partition (see "Add a Partition" or "Edit the Partition Attributes").

• Partition Name – Limit of 20 characters.

• Drive Auto Clean – If selected, this enables library-managed drive cleaning for drives within the partition (see "Configure Drive Auto Cleaning"). If not selected, the host software must manage drive cleaning.

• Volume Label Format – Controls presentation of the storage cell volsers (see "Volume Label Format Options").

• Initial Control State – The initial state of the partition. An ”Online” partition can respond to client requests. An "Offline" partition will reject all client requests until you set it "Online".

• SCSI Access Enabled – "Yes" means only SCSI clients can access the partition. "No" means only StorageTek Library Control Interface (SCI) clients can access the partition. See also "How the Library Avoids Conflicting Move Requests Between SCSI, SCI, and the GUI".

• Fast-Load Type – Defines how the partition handles replying to mount requests.

  • Normal (default) – The library will reply to a mount request only after the selected tape is loaded and threaded in the drive.

  • Fast – The library will reply to a mount request after the selected tape is inserted into the drive, but before loading and threading completes.

• CAP Pool Name – Select the CAP pool from the list (to create or modify CAP pools, see "Create a CAP Pool"). In order to import/export tapes, you must assign a CAP pool to the partition.

Edit the Partition Attributes

CAUTION:

Modifying the partitioning configuration can be disruptive to client systems. Any altered partitions currently online will temporarily go OFFLINE and then come back online. Partitions that were already offline will remain offline.

1. Click Partitioning in the left navigation area of the GUI.

2. Select the partition in the table, and then click Edit Partition .

3. Update the partition attributes (see "Partition Attributes").

See Also

• "Move Storage Cells and Drive Bays to a Partition"

• "Assign Partitions to a SCSI Host and Alter LUN Assignment"

Move Storage Cells and Drive Bays to a Partition

Initially, all resources are assigned to a predefined default partition. After you add at least one additional partition (see "Add a Partition"), you can move storage cells and drive bays between partitions. All storage cells and drive bays in the library must always belong to a partition.

Note:

No actual configuration changes are made to the library until you click Apply on the summary page. After applying changes, any altered partitions currently online will temporarily go OFFLINE. Partitions that were already offline will remain offline.

1. Click Partitioning in the left navigation area of the GUI.

2. Click Assign Cells .

3. From the drop-down lists, select the source and destination partition. The arrow indicates the direction the resources will move. Initially, the default partition must be the source partition.

   Note:

   Click the arrow to reverse the direction.
   
   

4. Click a module to modify (the green arrow below a module indicates the currently selected module).

   
   

5. Choose a Select Cells By method (see "Partitioning Selection Methods" below for definitions), and then click cells on the cell map (see "Partitioning Cell Map Legend" below). The number over a cell or drive bay indicates the partition ID.

   Oops...I made a mistake, how do I move cells back?

   Click the cell assignment direction arrow to flip the direction . Choose a Select Cells By method, and then click cells on the cell map. The cells reassign to the source partition.

6. Click another module and repeat.

7. Once you have completed the partitioning design, click Next.

   IMPORTANT:

   Applying changes will take any modified partitions temporarily OFFLINE. Unaffected partitions will remain ONLINE. You should stop any host operations involving the modified partitions before applying the partitioning changes.

8. Review the Cell Assignment Count Summary and Cell Assignment Details, and then click Apply.

Partitioning Selection Methods

In the Base Module and Drive Module, rows and columns do not align between drive bays and storage cells, therefore the only selection options you can use to select both storage and drive cells simultaneously are Side, Module, and Cell-by-Cell. The other selection methods only select like-cells, meaning the method only selects storage cells or only drive bays.

• Cell-by-cell – Assign cells one at a time by clicking individual cells.

• Cell Block – Assign like-cells in a rectangular block (two clicks required). Click the top-left corner of the block, and then click the bottom-right corner of the block (do not click-and-drag).

• Column – Assign all like-cells in a column by clicking any cell in the column.

• Side – Assign all cells on a side (front or back) by clicking any cell on the side.

• Row – Assign all like-cells in a row by clicking any cell in the row.

• Module – Assign all cells currently assigned to the source partition in a module by clicking any cell in the module.

Partitioning Cell Map Legend

Cell Map Icon	Meaning
	Tape - indicates that the cell is occupied or the drive is mounted.
(no color overlay)	Unallocated - cell assigned to the source partition (in this case partition with ID 1).
(yellow overlay)	Allocated - cell assigned to the destination partition (in this case partition with ID 21)
(red overlay)	Unselectable - cell assigned to a partition that is not one of the partitions currently selected in the drop-down lists. Or, the cell is a system cell. System cells cannot be assigned to any partition.
	CAP cell - you cannot assign these cells to a partition. The CAP cells assigned to the partition depend on the CAP pool.
	Inaccessible - a system cell. You cannot add these cells to a partition and hosts cannot access these cells.

Delete a Partition

You can only delete a partition if it contains no storage cells or drive bays.

1. Move all storage cells and drive bays from the partition to be deleted to another partition (see "Move Storage Cells and Drive Bays to a Partition").

   TIP:

   To quickly reassign all the cells in a module that belong to the source partition, choose the By Module selection method, and then click anywhere on the cell map.

2. On the assign cells summary screen, verify that the partition you want to delete contains zero resources, and then click Apply.

   
   

3. To delete the empty partition, click Partitioning in the left navigation area of the GUI.

4. Select the partition in the table, and then click Delete . If Delete is grayed-out, you must first move all storage cells and drive bays to another partition (see "Move Storage Cells and Drive Bays to a Partition").

   Note:

   Any SCSI hosts assigned to this partition will have their LUNs deleted. Additionally, the library may renumber some LUNs if the host has higher-numbered LUNs than the deleted partition. You will have to reconfigure the host.

Assign Partitions to a SCSI Host and Alter LUN Assignment

IMPORTANT:

Assigning a partition to a SCSI host will take the partition temporarily OFFLINE. Altering LUN numbering will be disruptive, requiring you to reconfigure the host.

1. Click Partitioning in the left navigation area of the GUI.

2. Click the SCSI Host Configuration tab.

3. Click Configure SCSI Connections .

4. Select a SCSI host from the drop-down list.

   Note:

   If a partition does not appear, SCSI access is not enabled. To enable SCSI access, see "Edit the Partition Attributes".

5. For each partition, select a LUN assignment. There must be a LUN 0 and you cannot have duplicate LUNs for a host. You can leave partitions unassigned.

   
   

6. If there are additional SCSI hosts to assign, select the host from the list and repeat.

7. Click Ok to initiate the reconfiguration, which will take the affected partitions offline and re-assign LUNs. Reconfigure the hosts as necessary.

See Also

• "Managing the SCSI Host Connection"

• "Add, Modify, or Delete a SCSI Host"

• "View the SCSI LUN Mapping"

• "View Actively Logged-In SCSI Hosts"

• "View the Host Connections of a Partition"

View the Host Connections of a Partition

1. Click Partitioning in the left navigation area of the GUI.

2. Click the Partitions tab.

3. Select a partition in the list. From the Actions drop-down (or right-click menu), select Properties.

See Also

• "Managing the SCSI Host Connection"

• "Assign Partitions to a SCSI Host and Alter LUN Assignment"

Place a Partition Online or Offline

Partitions will automatically be taken offline during partitioning and SCSI host configuration changes. However, you can also manually change the partition state. An offline partition will reject all client requests until you set it online.

1. Click Partitioning in the left navigation area of the GUI.

2. Click the Partitions tab.

3. Select the partition.

4. From the Actions drop-down (or right-click menu), select Go Online or Go Offline.

Why is there a Default Partition in a "Non-Partitioned" Library?

All resources (drive bays, storage cells, and CAPs) within the SL4000 library must always be contained within at least one partition. Therefore, in a non-partitioned library (meaning a library with partitioning disabled), there is a single default partition that contains the entire library. Initially, this partition is named "DefaultPartition", but you can rename or edit its partitioning attributes at anytime (see "Edit the Partition Attributes").

Why is there a Media Validation Partition?

The Media Validation partition dedicates T10000C and D drives for validating the integrity of T10000 tapes (see "Validating Media"). By default there is always a Media Validation partition (even in a library with partitioning disabled) and you cannot delete or rename the Media Validation partition. Initially the partition is empty and contains no resources. To add drives to the partition, see "Add or Remove Drives from the Media Validation Partition (Pool)".

What Occurs When You Disable Partitioning

After deactivating partitioning in the library settings, the library:

• Moves everything into a single default partition and deletes all other partitions.

• Moves all CAPs into a single DefaultPool owned by the DefaultPartition and deletes all other CAP pools.

• Deletes all SCSI LUNs greater than zero from all SCSI hosts and assigns SCSI LUN zero on each host to the default partition.