EMC Symmetrix DMX-3

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EMC Symmetrix DMX-3 Product Guide
Power Sequences
Vaulting
Vaulting allows the Symmetrix system to preserve the contents of
cache during a powerdown procedure. When a DMX-3 system is
powered down, transitioned to offline, or environmental conditions
trigger a vault situation, a vaulting procedure is initiated. This
procedure writes all information in cache above a certain point or
vault line to the first hypers of designated drives. These are called
vault drives. When a system is brought back online, the vault hypers
write the stored information back into global memory.
A vault save is initiated under the following circumstances:
◆ System VTOC
◆ When the system is taken offline (DAs taken offline)
◆ Power loss
◆ Whenever the environment monitor determines:
• A loss of vault drives that indicate a “Need to Vault”
• A loss of battery holdup time will indicate a "Need to Vault"
• A loss of BBU battery holdup time will prevent the system
from powering up due to a lack of battery power to complete
the vault (minimum 300 sec needed)