Hitachi Universal Storage Platform V Reference Manual page 62

Mode Category
503 Common
505 Virtual Partition
Manager
3-18
Hitachi Universal Storage Platform V/VM User and Reference Guide
For the Install CV, Make Volume, and Volume Initialize
functions of Virtual LVI/LUN, after LDEVs are installed, LDEV
format is suppressed, and a blocked LDEV is created.
Also, VLL operations and the UVM Add LU and Delete LU
operations are available even when an LDEV is blocked or
being formatted.
Mode 503 = ON:
1. When using VLL to perform Install CV, Volume Initialize, or
Make Volume, LDEVs can be added without performing the
LDEV format operation.
2. Even during LDEV formatting/shredding, or when an LDEV
is blocked, or when HDD copy*1 or spare HDD operation*2
is in operation, the following operations will be available for
the LDEVs in different parity groups:
Virtual LVI/LUN: Install CV, Volume To Space, Volume
Initialize, Make Volume
Universal Volume Manager: Add LU/ Delete LU,
Disconnect/ Check Path & Restore
Copy-on-Write Snapshot: New V-VOL Group/ Delete V-
VOL Group
Dynamic Provisioning: New V-VOL Group/ Delete V-VOL
Group (USP V/VM only)
3. Even if the HDD copy is in operation, LDEV formatting and
shredding are available for LDEVs in different parity
groups.
*1: HDD copy: Executing copy operation to spare HDD and
copy back.
*2: Spare HDD operation: Spare HDD is in use.
Mode 503 = OFF: After LDEV installation using VLL, LDEV
format is performed, and VLL operations cannot be performed
when an LDEV is blocked.
Note:
You can never execute any operations in #2 and #3 in
Function above on LDEVs within a parity group that has a
failed/blocked drive. However, these operations are
available if only the spare drive is failed/blocked.
When a drive failure occurs, Mode 503 = ON will allow the
operations in #2 and #3 in Function above on LDEVs within
different parity groups than the one with the failed HDD.
When mode 503 is ON, LDEV format processing is
prevented, so the High Speed Format function for VLL
operations (mode 269 ON) is not available.
In conventional VLL operations performed by users, LDEV
is not blocked unless a failure occurs. When LDEV format is
not performed, however, LDEV can be blocked even when
no failure occurs.
For details about the relationship between mode 503 and
mode 269, see Table 3-2 and Table 3-3 below.
Speed up changing CLPR cache assignment, and reduce the
processing time to a maximum of one minute per 1 GB.
Mode 505 = ON: Speed up changing CLPR cache assignment
(max 1 minute per 1 GB).
Mode 505 = OFF: Speed of changing CLPR cache assignment
is normal (max 5 minutes per 1 GB).
Functional and Operational Characteristics
Function Default MCU/RCU
OFF –
OFF –