Unable to update path from rst0 to nrst0. Why?

[combato]

Hi Pro's!

I have some paths configured to a nas filer. All the tsm paths have it's device pointed to the nas filer device "rewind device" e.g:

tsm: TSMSERV1>q path filer.domain.com f=d

Source Name: FILER.DOMAIN.COM
Source Type: DATAMOVER
Destination Name: TAPE01
Destination Type: DRIVE
Library: TSMSERV1
Node Name:
Device: rst2a
External Manager:
ZOS Media Server:
Comm. Method:
LUN:
Initiator: 0
Directory:
On-Line: Yes
Last Update by (administrator): COMBATO
Last Update Date/Time: 12/17/2015 15:22:29

I heard that it should be "no rewind device" e.g: nrst2a to save the tape drive from winding the tape forward and backward every time a write to the tape finish. I therefore tried to update all my paths to "no rewind devices" but when I do this the path is automatically changed back to the rewind device type again. Like this:

12/17/2015 15:22:29 ANR2017I Administrator COMBATO issued command: UPDATE
PATH filer.domain.com tape01 srct=datamover destt=drive
libr=tsmlibrary01 devi=nrst2a (SESSION: 7545)
12/17/2015 15:22:30 ANR8871I The device name nrst2a specified has been changed
to rst2a. (SESSION: 7545)

Why?

 

[Trident]

Device is dependant upon operating system. For unix sysems, it is typically /dev/nst0. Windows has its own standard, and so does the other OS vendors too.

 

[combato]

Thanks 'Trident', but my devices are named as I described above. Here is output how I looks in my netapp filer (sysconfig -t):
Tape drive (fcswitch01:1.17) IBM LTO-6 ULT3580
rst2l - rewind device, format is: LTO-4/5 Native Density
nrst2l - no rewind device, format is: LTO-4/5 Native Density
urst2l - unload/reload device, format is: LTO-4/5 Native Density
rst2m - rewind device, format is: LTO-4/5 Compressed
nrst2m - no rewind device, format is: LTO-4/5 Compressed
urst2m - unload/reload device, format is: LTO-4/5 Compressed
rst2h - rewind device, format is: LTO-6 2.5TB
nrst2h - no rewind device, format is: LTO-6 2.5TB
urst2h - unload/reload device, format is: LTO-6 2.5TB
rst2a - rewind device, format is: LTO-6 6.25TB Compressed
nrst2a - no rewind device, format is: LTO-6 6.25TB Compressed
urst2a - unload/reload device, format is: LTO-6 6.25TB Compressed

I have been running my backup on "rst2a" for some years, but I now want to change this to "nrst2a".
The drives are connect with fibrechannel from the netapp to my tape devices and TSM has datamovers configured and paths to find the correct device when running backups.

 

[Trident]

Hi,

Ok. I am not going to explain that. If TSM wnats the device to be rst2a, leave it at that.
H.

 

[combato]

Ok, but don't you think it's better to use "nrst" to save drives and tapes from rewinding? I'm just curious...
Thanks, /C