AIX Tape Device Management
When using tape devices it is often necessary to change parameters to tune for performance. This QRG describes the process for changing configuration parameters for AIX tape devices to tune for optimal performance. The parameters used are the recommended settings which are often specified by the application using the device or the device manufacturer.
Listing Devices
The following command lists all the devices configured on a system. It should be used to determine the exact device to manage.
The example provided here uses these commands to change the block size for a tape device.
Command:
lsdev
Output example:
# lsdev
L2cache0 Available L2 Cache
aio0 Defined Asynchronous I/O (Legacy)
cd0 Available 05-08-00 IDE DVD-ROM Drive
en0 Available 03-08 Standard Ethernet Network Interface
en1 Defined 03-09 Standard Ethernet Network Interface
ent0 Available 03-08 2-Port 10/100/1000 Base-TX PCI-X Adapter (14108902)
ent1 Available 03-09 2-Port 10/100/1000 Base-TX PCI-X Adapter (14108902)
et0 Defined 03-08 IEEE 802.3 Ethernet Network Interface
et1 Defined 03-09 IEEE 802.3 Ethernet Network Interface
fcnet0 Defined 01-08-01 Fibre Channel Network Protocol Device
fcs0 Available 01-08 FC Adapter
fcs1 Defined 01-08 FC Adapter
fscsi1 Available 01-08-02 FC SCSI I/O Controller Protocol Device
fwdump Defined Logical volume
gxme0 Defined Graphics Data Transfer Assist Subsystem
hd1 Defined Logical volume
hd2 Defined Logical volume
hd3 Defined Logical volume
hd4 Defined Logical volume
hd5 Defined Logical volume
hd6 Defined Logical volume
hd8 Defined Logical volume
hd10opt Defined Logical volume
hd9var Defined Logical volume
hdisk0 Available 06-08-01-5,0 16 Bit LVD SCSI Disk Drive
hdisk1 Available 06-08-01-8,0 16 Bit LVD SCSI Disk Drive
ide0 Available 05-08 ATA/IDE Controller Device
inet0 Available Internet Network Extension
iscsi0 Available iSCSI Protocol Device
lo0 Available Loopback Network Interface
loglv00 Defined Logical volume
lv00 Defined Logical volume
lvdd Available LVM Device Driver
mem0 Available Memory
pci0 Available PCI Bus
pci1 Available PCI Bus
pci2 Available PCI Bus
pci3 Available 00-10 PCI Bus
pci4 Available 00-12 PCI Bus
pci5 Available 00-13 PCI Bus
pci6 Available 00-14 PCI Bus
posix_aio0 Defined Posix Asynchronous I/O
proc0 Available 00-00 Processor
proc2 Available 00-02 Processor
pty0 Available Asynchronous Pseudo-Terminal
rcm0 Defined Rendering Context Manager Subsystem
rmt0 Available 01-08-02 Other FC SCSI Tape Drive
rmt1 Available 01-08-02 Other FC SCSI Tape Drive
rootvg Defined Volume group
scsi0 Available 06-08-00 PCI-X Dual Channel Ultra320 SCSI Adapter bus
scsi1 Available 06-08-01 PCI-X Dual Channel Ultra320 SCSI Adapter bus
ses0 Available 06-08-01-15,0 SCSI Enclosure Services Device
sisscsia0 Available 06-08 PCI-X Dual Channel Ultra320 SCSI Adapter
sys0 Available System Object
sysplanar0 Available System Planar
usb0 Available USB System Software
usbhc0 Available 04-08 USB Host Controller (33103500)
usbhc1 Available 04-09 USB Host Controller (33103500)
vio0 Available Virtual I/O Bus
vsa0 Defined LPAR Virtual Serial Adapter
vsa1 Available LPAR Virtual Serial Adapter
vty0 Defined Asynchronous Terminal
vty1 Available Asynchronous Terminal
List Device Attributes
After obtaining the device insurance more details for the device can be shown using the lsattr command.
Command syntax:
lsattr -l <DEVICE> -E
Output example:
bu07# lsattr -l rmt2 -E
block_size 512 BLOCK size (0=variable length) True
delay 45 Set delay after a FAILED command True
density_set_1 0 DENSITY setting #1 True
density_set_2 0 DENSITY setting #2 True
extfm yes Use EXTENDED file marks True
location Location Label True
lun_id 0x3000000000000 Logical Unit Number ID False
mode yes Use DEVICE BUFFERS during writes True
node_name 0x500a09800000a7af FC Node Name False
res_support no RESERVE/RELEASE support True
ret_error no RETURN error on tape change or reset True
rwtimeout 144 Set timeout for the READ or WRITE command True
scsi_id 0x10800 SCSI ID False
var_block_size 0 BLOCK SIZE for variable length support True
ww_name 0x510a09800000a7af FC World Wide Name False
bu07#
bu07# lsdev
L2cache0 Available L2 Cache
aio0 Defined Asynchronous I/O (Legacy)
cd0 Available 05-08-00 IDE DVD-ROM Drive
en0 Available 03-08 Standard Ethernet Network Interface
en1 Defined 03-09 Standard Ethernet Network Interface
ent0 Available 03-08 2-Port 10/100/1000 Base-TX PCI-X Adapter (14108902)
ent1 Available 03-09 2-Port 10/100/1000 Base-TX PCI-X Adapter (14108902)
et0 Defined 03-08 IEEE 802.3 Ethernet Network Interface
et1 Defined 03-09 IEEE 802.3 Ethernet Network Interface
fcnet0 Defined 01-08-01 Fibre Channel Network Protocol Device
fcs0 Available 01-08 FC Adapter
fcs1 Defined 01-08 FC Adapter
fscsi1 Available 01-08-02 FC SCSI I/O Controller Protocol Device
fwdump Defined Logical volume
gxme0 Defined Graphics Data Transfer Assist Subsystem
hd1 Defined Logical volume
hd2 Defined Logical volume
hd3 Defined Logical volume
hd4 Defined Logical volume
hd5 Defined Logical volume
hd6 Defined Logical volume
hd8 Defined Logical volume
hd10opt Defined Logical volume
hd9var Defined Logical volume
hdisk0 Available 06-08-01-5,0 16 Bit LVD SCSI Disk Drive
hdisk1 Available 06-08-01-8,0 16 Bit LVD SCSI Disk Drive
ide0 Available 05-08 ATA/IDE Controller Device
inet0 Available Internet Network Extension
iscsi0 Available iSCSI Protocol Device
lo0 Available Loopback Network Interface
loglv00 Defined Logical volume
lv00 Defined Logical volume
lvdd Available LVM Device Driver
mem0 Available Memory
ovpass0 Available 01-08-02 VERITAS Media Changer
pci0 Available PCI Bus
pci1 Available PCI Bus
pci2 Available PCI Bus
pci3 Available 00-10 PCI Bus
pci4 Available 00-12 PCI Bus
pci5 Available 00-13 PCI Bus
pci6 Available 00-14 PCI Bus
posix_aio0 Defined Posix Asynchronous I/O
proc0 Available 00-00 Processor
proc2 Available 00-02 Processor
pty0 Available Asynchronous Pseudo-Terminal
rcm0 Defined Rendering Context Manager Subsystem
rmt0 Available 01-08-02 Other FC SCSI Tape Drive
rmt1 Available 01-08-02 Other FC SCSI Tape Drive
rmt2 Available 01-08-02 Other FC SCSI Tape Drive
rmt3 Available 01-08-02 Other FC SCSI Tape Drive
rootvg Defined Volume group
scsi0 Available 06-08-00 PCI-X Dual Channel Ultra320 SCSI Adapter bus
scsi1 Available 06-08-01 PCI-X Dual Channel Ultra320 SCSI Adapter bus
ses0 Available 06-08-01-15,0 SCSI Enclosure Services Device
sisscsia0 Available 06-08 PCI-X Dual Channel Ultra320 SCSI Adapter
sys0 Available System Object
sysplanar0 Available System Planar
usb0 Available USB System Software
usbhc0 Available 04-08 USB Host Controller (33103500)
usbhc1 Available 04-09 USB Host Controller (33103500)
vio0 Available Virtual I/O Bus
vsa0 Defined LPAR Virtual Serial Adapter
vsa1 Available LPAR Virtual Serial Adapter
vty0 Defined Asynchronous Terminal
vty1 Available Asynchronous Terminal
bu07#
List the rmt2 device and change the block size to variable.
Command syntax:
# lsattr -l rmt2 -E
Output example:
bu07# lsattr -l rmt2 -E
block_size 512 BLOCK size (0=variable length) True
delay 45 Set delay after a FAILED command True
density_set_1 0 DENSITY setting #1 True
density_set_2 0 DENSITY setting #2 True
extfm yes Use EXTENDED file marks True
location Location Label True
lun_id 0x3000000000000 Logical Unit Number ID False
mode yes Use DEVICE BUFFERS during writes True
node_name 0x500a09800000a7af FC Node Name False
res_support no RESERVE/RELEASE support True
ret_error no RETURN error on tape change or reset True
rwtimeout 144 Set timeout for the READ or WRITE command True
scsi_id 0x10800 SCSI ID False
var_block_size 0 BLOCK SIZE for variable length support True
ww_name 0x510a09800000a7af FC World Wide Name False
bu07#
Need to change the current setting from 512 to 0. Use the chdev command.
Command syntax:
# chdev -l rmt2 -a block_size=0
Output example:
bu07# chdev -l rmt2 -a block_size=0
rmt2 changed
bu07# lsattr -l rmt2 -E
block_size 0 BLOCK size (0=variable length) True
delay 45 Set delay after a FAILED command True
density_set_1 0 DENSITY setting #1 True
density_set_2 0 DENSITY setting #2 True
extfm yes Use EXTENDED file marks True
location Location Label True
lun_id 0x3000000000000 Logical Unit Number ID False
mode yes Use DEVICE BUFFERS during writes True
node_name 0x500a09800000a7af FC Node Name False
res_support no RESERVE/RELEASE support True
ret_error no RETURN error on tape change or reset True
rwtimeout 144 Set timeout for the READ or WRITE command True
scsi_id 0x10800 SCSI ID False
var_block_size 0 BLOCK SIZE for variable length support True
ww_name 0x510a09800000a7af FC World Wide Name False
bu07#
Summary
# lsattr -l rmt3 -E
# chdev -l rmt3 -a block_size=0
# lsattr -l rmt3 -E