Tectia Server for IBM z/OS can transfer files to and from cataloged, online DASD (direct access storage device) datasets. The following dataset types are supported:
uncataloged DASD datasets
migrated DASD datasets
offline DASD datasets
cataloged tape datasets
uncataloged tape datasets
offline tape datasets
Tectia relies on the system security product for access control to
datasets. Because of this, tape datasets must have identifying tape labels.
Tectia will not allow the use of NL
(No Label) or
BLP
(Bypass Label Processing). Tectia does not read labels
and does not have any label exits.
Using an offline tape dataset requires that a tape drive is available and that the tape cassette is mounted on the drive. The operator must mount the drive or cancel the mount request. Outstanding mount requests can cause shortages, locking and deadlocks in resource handling in the system.
Using datasets on offline DASD volumes requires that the operator varies the volume device online. This requires the operator to decide whether the device can be varied online (it is probably offline for a good reason) and to enter the vary command or cancel the request.
Using a migrated dataset requires the system to recall the dataset to a user-accessible (level 0) volume before it can be read or overwritten. If the dataset is on a migration level 1 (DASD) or migration level 2 (tape) volume, it is first copied to level 0.
The z/OS system operators must monitor mount requests to make sure they do not go unanswered or cause problems. They must also monitor the system for Tectia SFT Server processes and Tectia file transfer clients that are hanging on allocation requests for offline datasets.
In Tectia Server for IBM z/OS, mounting an offline dataset is by default not allowed and recalling a migrated dataset is by default allowed.
The Tectia end user controls mounting and recalling with the extended
file attributes automount
and autorecall
.
The user must set automount
to
yes
or immed
for Tectia
to attempt to mount offline datasets. The user can set
autorecall
to no
to avoid
recalling a dataset by mistake.
In addition, the administrator must set up access rights to the RACF
facility SSZ.MOUNT
for the users who will be mounting
offline datasets with Tectia client tools for z/OS. For more information, see
Tectia Server for IBM z/OS Administrator Manual.
Existing datasets that do not have entries in the catalog can be
accessed by specifying a volume serial number and unit. For example, to read a tape
dataset that has the data set name SRVACC1.SPECS.PDF
and is the third dataset on volume 456123
:
sftp> site unit=TAPE,volumes=456123,dataset_sequence_number=3 sftp> sget //'SRVACC1.SPECS.PDF' /home/clusr1/tmp/specs.pdf
To create a dataset without cataloging it use the
normdisp
attribute:
sftp> site unit=tape,normdisp=keep sftp> sput /home/clusr1/tmp/specs-v2.pdf //'SRVACC1.SPECS.V2.PDF'
The dataclass
, storclass
, and
mgmtclass
attributes are also available.
For Tectia to request the system to mount an offline volume, you must
use the automount=yes
attribute. You must also have
READ
access to SSZ.MOUNT
. For example,
to read a dataset on a tape volume, assuming that the dataset has a catalog
entry, use the following commands:
sftp> site automount=yes sftp> sget //'SRVACC1.SPECS.PDF' /home/clusr1/tmp/specs.pdf
When automount=yes
, Tectia first attempts to allocate
the dataset without allowing the system to mount the dataset if it is
offline. If this allocation fails, Tectia retries the allocation with the
mount request. The user can make Tectia omit the first attempt by specifying
automount=immed
.
Tectia has a facility for low-level access to dynamic file allocation because of the large number of attributes that can be specified when allocating tape datasets.
Tectia allocates datasets by calling the SVC 99 interface. This interface has a table of text units. Each text unit consists of key, parameter count, and parameters. The parameters have a length field and data. The interface is documented in the Authorized Assembler Services Guide.
Tectia allocates files at the start of a file transfer (except if the
file is already allocated and is represented by a DD name). Tectia sets text
units based on the extended attributes. The
svc99_text_units
SITE attribute, allows
the user to add and change text units in the table. The value of
svc99_text_units
is a sequence of text units delimited by
underscores ('_
'). Each text unit has the format
xxxx
F
values
,
where xxxx
is the key in hexadecimal,
F
is a format character and
values
is a character string. The
values
part is empty or consists of one string or
of several strings delimited by plus signs ('+
'). No value
may contain spaces, tabs, newlines or any of the characters
'_+,/\
'. The values
part must
not exceed 80 characters in length.
The format character indicates how the value(s) are encoded. The possible values are:
S
: character string
X
: hexadecimal
F
: decimal number with length 4 in the text unit
H
: decimal number with length 2 in the text unit
C
: decimal number with length 1 in the text unit
-
: no text unit
When the format character is '-
', Tectia removes the
text unit with the given key if it is in the table. For the other
characters, Tectia replaces the value in the text unit with the given key or
adds a new text unit.
The following attributes show how to encode some of the examples in the Authorized Assembler Services Guide. The attributes are not intended to be practical cases.
To specify an accessibility code of Z for an ANSI tape data set:
sftp> site svc99_text_units=8001XE9
To specify a RACF profile that was defined generically and request unallocation when a DCB is closed:
sftp> site svc99_text_units=800EXD9D7D9D6C6+80_001CX
To enter a Key Encode Specification and a Key Label:
sftp> site svc99_text_units=8026SH_8024SLABELQ1.LABELQ2.LABELQ3