Transferring control of a tape drive from i5/OS to Linux

This topic discusses how to transfer control of a tape drive from i5/OS™ to Linux^®.

Before you use an iSeries™ tape drive for a Linux backup application, you must make it unavailable from the i5/OS side using iSeries Navigator or a CL command, and then lock it on the Linux side through a Linux terminal session.

Note that some tape devices report in under more than one device description. Tape libraries (3570, 358x, 3590, and so on) report in as tape libraries (TAPMLBxx) as well as tape devices (TAPxx), where xx is a sequence number. The Linux integration support software does not support the tape library function. Therefore, if your device has a tape library description, both the tape and tape library devices must be made unavailable (varied off) before locking the device on the Linux server. Note that, although tape libraries are not supported as libraries in Linux, you can use them in sequential mode if the drive supports it.

If you have multiple integrated Linux servers being hosted by the same i5/OS partition, only one server at a time can use a particular iSeries tape drive. If you have multiple logical partitions on your iSeries, a tape drive that is owned by one partition cannot be shared by integrated Linux servers that are being hosted by other partitions. Note, however, that it might be possible to logically switch tape drives between i5/OS partitions, depending on the hardware configuration of the iSeries.

To transfer control of a tape drive from an i5/OS partition to an integrated Linux server, you must have i5/OS Administrator or Backup Operator authority.

To transfer control of an iSeries tape drive from i5/OS to Linux, choose one of the two following methods:

Transferring control of a tape drive with iSeries Navigator

To transfer control of an iSeries tape drive with the iSeries Navigator, complete the following steps:

From an iSeries Navigator window, expand the i5/OS partition you are working with.
Click Configuration and Service > Expand > Hardware > Tape Devices.
Click Stand-Alone Devices and then right-click the tape device you want to transfer control of to Linux. Select Make Unavailable.
If the tape device is also a tape library, click Tape Libraries and then right-click the tape library you want to transfer control of to Linux. Select Make Unavailable.
To lock the tape device to Linux, start a Linux terminal session and log in as root.
At the command prompt enter the ixsdev command and press Enter. The syntax is:
```
ixsdev [-list] | [[-lock | -unlock] device name]
```
For example, to list the tape and optical drives accessible by Linux enter the following command:
```
ixsdev -list
```
To lock TAP02 to Linux you would enter the following command:
```
ixsdev -lock TAP02
```
Note: In Linux, commands are case sensitive. Make sure you use the same case as in our examples, for example, use TAP02 not tap02.

You could also use the Linux name. ixsdev -lock /dev/st1 for a rewindable tape device, or ixsdev -lock /dev/nst1 for a non-rewindable tape device. The ixsdev -list command shows the status of TAP02 as LOCKED.

Note that you do not need to mount the tape device because Linux does not see it as a block device. You only need to mount block devices.
Insert a tape cartridge that has been formatted for Linux.

Transferring control of a tape drive with CL commands

To transfer control of an iSeries tape drive with CL commands, complete the following steps:

On the i5/OS command line, use this command to vary off the tape device:
```
WRKCFGSTS *DEV *TAP
```
On the Work with Configuration Status display, find the tape device you want to transfer control of to Linux. Type 2 next to the device and press Enter.
If the tape device is also configured as a tape library, enter the following command:
```
WRKCFGSTS *DEV *TAPMLB
```
On the Work with Configuration Status display, find the tape library corresponding to the tape device you want to transfer control of to Linux. Type 2 next to the tape library and press Enter.
To lock the tape device to Linux, start a Linux terminal session and log in as root.
At the command prompt enter the ixsdev command and press Enter. The syntax is:
```
ixsdev [-list] | [[-lock | -unlock] device name]
```
For example, to list the tape and optical drives accessible by Linux enter the following command:
```
ixsdev -list
```
To lock TAP02 to Linux you would enter the following command:
```
ixsdev -lock TAP02
```
Note: In Linux, commands are case sensitive. Make sure you use the same case as in our examples, for example, use TAP02 not tap02.

You could also use the Linux name. ixsdev -lock /dev/st1 for a rewindable tape device, or ixsdev -lock /dev/nst1 for a non-rewindable tape device. The ixsdev -list command shows the status of TAP02 as LOCKED.

Note that you do not need to mount the tape device because Linux does not see it as a block device. You only need to mount block devices.
Insert a tape cartridge that has been formatted for Linux.

After the tape drive has been logically switched to the integrated Linux server, you can use it in the same way as you would use a tape drive directly attached to a standalone Linux server. Using a Linux backup application, you can now direct your Linux backups to the iSeries tape drive.