The important attributes and behavior of SM pubsets and volume sets that are required in order to gain an understanding of SMPGEN are described below. The concept of
SM pubsets is discussed in detail in the “System-Managed Storage” manual [8 (Related publications)] or in the “Introduction to System Administration” [5 (Related publications)].
Pubset attributes
SM and SF pubsets have the following attributes in common:
they are generally put into and taken out of operation in their entirety
they form a name space for files, job variables and guards
the storage location of a file within a pubset is determined by the system (except for “physical” allocation, for which the user requires special rights)
they can be created as “large pubsets” or be converted to these. Large pubsets support files and volumes which are over 32 GB.
there are user-related storage, file and job-variable quotas (limits) valid throughout the pubset
there are user-related rights valid throughout the pubset (right to high-performance file processing, PUBLIC-SPACE-EXCESS, right to physical allocation)
However, unlike SF pubsets, SM pubsets are not unstructured (except for the distinction between Pubres and other disks. Within an SM pubset, there are usually several sets of associated disks with similar VSNs; these are referred to as the volume set.
An SM pubset can consist of a maximum of 255 volume sets.
If one of these volume sets fails, it can be removed from the SM pubset configuration and the SM pubset operated without it. The files that were present in this volume set can be retrieved selectively from existing backups.
Exception: If the control volume set fails, the SM pubset can no longer be operated.
Volume set attributes
Some attributes that apply to the whole of an SF pubset apply in an SM pubset only to the individual volume sets. Such attributes include the following:
the volume set identifier forms part of the VSN of the associated disks, completely analogous to the SF pubset ID
the allocation unit is the same on all disks
the disk format (K, NK2, NK4) matches
the DRV attribute corresponds as generation attribute
the DRV/SRV mode is not set for single public disks but for an entire volume set
the cache configuration is volume-set-related
all extents of a file lie within a volume set
On account of the division into several volume sets, an SM pubset, and so too a file name space, can support serval different services and may therefore be used as a suitable mass storage option for different files.
Since the volume sets for storage on a particular file are not equally suitable, they are assigned logical volume set attributes:
AVAILABILITY, PERFORMANCE, WRITE-CONSISTENCY. These are used by the system along with the logical file attributes to determine the most suitable storage location for a file.
A volume set of the SM pubset, the control volume set, is used to store the most important metadata (e.g. volume set configuration, user entries, file catalog references, protection profiles). It must therefore not be removed from the SM pubset in the event of an error. If enhanced security is required, it is useful to used DRV disk pairs or a disk pair operated with DUALCOPY for this volume set, or to make a DRV (SF) pubset the control volume set.
The volume sets that form an SM pubset are distinguished according to their use as: USAGE=*STD, USAGE=*WORK and USAGE=*HSMS-CONTROLLED volume sets. USAGE=*STD volume sets are used for normal file storage, USAGE=*WORK volume sets for storing work files, and USAGE=*HSMS-CONTROLLED volume sets are used by HSMS in the background in SM pubsets supported in HSMS.
SMPGEN supports USAGE=*STD and USAGE=*HSMS-CONTROLLED volume sets. Volume sets with USAGE=*WORK must be added using reconfiguration commands.
Storage space quotas
The quotas described below refer to a user ID and an SM pubset: they are not broken down over individual volume sets.
The storage space quotas on an SM pubset are more complex than on an SF pubset. The following three quota structures coexist:
Quota for permanent files
(these are all files that are not work files and are not temporary files)Quota for temporary files
Quota for work files
“Quota structure” means that there is one storage space quota for these three types of files which defines the entire storage space that can be allocated by these files. In addition, there are so-called subquotas which can be used to further restrict the allocation of especially valuable resources.
For permanent files, the quota structure is as follows:
where the quota names have the following meaning:
TOTAL-SPACE(PERM)
is the space for all permanent files on the pubset, including those on background levels. If the file lies on a background level, what is allocated is not the real storage space; but the space that it would take up on the S0 level for a recall.S0-LEVEL-SPACE(PERM)
is the space which permanent files take up on the S0 level of the pubset. This corresponds to the quota PUBLIC-SPACE-LIMIT on SF pubsets.HIGH-PERF-SPACE(PERM)
is the space which permanent files with an enhanced-performance attribute (PERFORMANCE=*HIGH or *VERY-HIGH) take up on the S0 level of the pubset.VERY-HIGH-PERF-SPACE(PERM)
is the space which permanent files with the attribute PERFORMANCE=*VERY-HIGH take up on the S0 level of the pubset.HIGH-AVAILABILITY-SPACE(PERM)
is the space which permanent files with the high-availability attribute
(AVAILABILITY=*HIGH) take up on the SO level of the pubset.
For temporary files and work files, the quota structure is as follows:
The significance of quotas corresponds to that of permanent files.
The suffix <quota name>(TEMP) or <quota name>(WORK) indicates that the quota applies to temporary files or work files respectively.
The quota for S0-LEVEL-SPACE and HIGH-AVAIL-SPACE is not necessary since only permanent files can be migrated or assigned the attribute AVAILABILITY=*HIGH.
The quota TOTAL-SPACE(TEMP) corresponds to the quota TEMP-SPACE-LIMIT on
SF pubsets.
The storage space allocation counter in the user entries corresponds to the quota structure.
The quota structure is more simple on the group level:
Only the values TEMP-SPACE-LIMIT and PUBLIC-SPACE-LIMIT familiar from SM pubsets, as well as the new limit WORK-SPACE-LIMIT are present.
(The above-mentioned limits form restrictions for the group administrator in how he or she can assign quotas to a member of the group; they should not be understood as quotas for the set of all group members).