Table 30 Tpp Thresholds; Table 31 Tpv Thresholds; Figure - Fujitsu ETERNUS DX S5 Series Design Manual

2. Basic Functions
Operations Optimization (Virtualization/Automated Storage Tiering)
●
Threshold Monitoring of Used Capacity
When the used capacity of a TPP reaches the threshold, a notification is sent to the notification destination,
(SNMP Trap, e-mail, or Syslog) specified using the [Setup Event Notification] function. There are two types of
thresholds: "Attention" and "Warning". A different value can be specified for each threshold type.
Also, ETERNUS SF Storage Cruiser can be used to monitor the used capacity.
• TPP Thresholds
There are two TPP usage thresholds: Attention and Warning.
Table 30
Threshold
Attention
Warning
TPV Thresholds
•
There is only one TPV usage threshold: Attention. When the physically allocated capacity of a TPV reaches
the threshold, a response is sent to a host via a sense. The threshold is determined by the ratio of free
space in the TPP and the unallocated TPV capacity.
Table 31
Threshold
Attention
Caution
• Use of Thin Provisioning is also not recommended when the OS writes meta information to the
whole LUN during file system creation.
• TPVs should be backed up by file. While backing up a whole TPV is not difficult, unallocated areas
will also be backed up as dummy data. If the TPV then needs to be restored from the backup, the
dummy data is also "restored". This requires allocation of the physical drive area for the entire TPV
capacity, which negates the effects of thin provisioning.
• For advanced performance tuning, use standard RAID groups instead of TPPs.
• Refer to the applicable OS and file system documentation before dynamically expanding the volume
capacity because expanded volumes may not be recognized by some types and versions of server-
side platforms (OSs).
• If a TPP includes one or more RAID groups that are configured with Advanced Format drives, all TPVs
created in the relevant TPP are treated as Advanced Format volumes. In this case, the write
performance may be reduced when accessing the relevant TPV from an OS or an application that
does not support Advanced Format.
TPP Thresholds
Selectable range
5 (%) – 80 (%)
5 (%) – 99 (%)
TPV Thresholds
Selectable range
1 (%) – 100 (%)
Default Setting conditions
Attention threshold £ Warning threshold
75 (%)
The "Attention" threshold can be omitted.
90 (%)
61
Default
80 (%)
Design Guide