Thin provisioning of the VMAX3 volumes is transparent for BS2000. The volumes are displayed as thin devices with the preconfigured capacity which is theoretically available.
As the volumes with storage areas are constructed from different, automatically allocated thin pools, no allocation to a thin pool, to a RAID type, or to a physical device can be determined. No information on this subject is provided by the /SHOW-SYMMETRIX-DEVICE-CONFIG command.
Data devices
Data devices are internal devices configured in VMAX3 for configuring the thin pools. They provide storage space to accommodate the contents of the thin devices. Data devices cannot be accessed by the server.
A sufficient number of adequately sized data devices must be configured and activated.
The /SHOW-SYMMETRIX-DEVICE-CONFIG TYPE=*DATA-DEVcommand selects data devices. These are labeled with DATA-DEV in the TYPE column.
The /SHOW-SYMMETRIX-DEVICE-CONFIG INFORMATION=*DATA-DEVICES command displays the specific properties of a data device with the assignment to a thin pool and the specific capacity values. See the examples on "SHOW-SYMMETRIX-DEVICE-CONFIG Displays the device configuration (Symmetrix/VMAX3)".
Thin pools
Data devices are managed in VMAX3 in so-called thin pools. Each thin pool is available to the user in its entirety for his/her thin devices.
CAUTION!
When the thin pools of a Storage Resource Pool are full (overflow), no more storage space can be provided for the assigned volumes for writes. The applications which are using it encounter an error (remount message). The functions of SHC-OSD for monitoring the thin pools should thus be used.
The /SHOW-SYMMETRIX-CONFIGURATION INFORMATION=*THIN-POOLS command displays information on the thin pools, including their current occupancy levels. See the example on "SHOW-SYMMETRIX-CONFIGURATION Displays the configuration (Symmetrix/VMAX3)".
Monitoring the thin pools
SHC-OSD offers monitoring of the occupancy levels of the monitored thin pools for VMAX3. See also the THIN-POOL-MONITORING parameter in the SHC-OSD parameter file (see the section "Configuration of SHC-OSD").
As the provision of storage areas (provisioning) takes place not at volume level but at track level, the monitoring cannot refer to volumes. The thin pool is monitored as a whole.
Messages NDE0070 and NDE0071 (which you can answer) on the console show when a particular limit value for the occupancy level of a thin pool has been exceeded. The THIN-POOL-SAT operand in the /MODIFY-SHC-PROCESSING command or the THIN-POOL-SATURATION parameter in the SHC-OSD parameter file determines the limit value (default value 80%). The current value can be inquired with /SHOW-SHC-PROCESSING.
When the limit value is reached, administrative intervention enables further capacity to be provided. When sufficient space is once more available in the thin pool, this is indicated by messages NDE0075/NDE0076 on the console. Messages NDE0070/NDE0071 are then answered automatically.