Avago Technologies 3ware 9650SE-12ML (Channel) - Manual (Page 138)

Configuring Units
126 3ware SAS/SATA RAID Software User Guide, Version 9.5.1
5 Press Enter to display the choices, use the arrow keys to select the
setting you want, and press Enter again to choose it.
6 Tab to the OK button and press Enter to select it.
You return to the main 3BM screen.
7 When you are finished making changes, press F8 to save them and exit
3BM.
Rapid RAID Recovery
The Rapid Raid Recovery feature increases the speed with which a redundant
unit can be made redundant again when a rebuild is required. It can also
increase the speed of verification or initialization that may occur in the event
of an unclean shutdown.
Rapid RAID Recovery is possible because the firmware maps the unit, and
tracks the areas of the unit where write activity occurs. Then, if a rebuild,
initialization, or verify is required, the controller only has to address the active
areas. The fewer active areas, the faster the rebuild, initialize or verify.
Since the units are mapped out and tracked from the creation of the unit, this
feature can only be enabled during unit creation. Also, once disabled, it
cannot be re-enabled.
If all of a unit’s capacity is being used, there is no real advantage to Rapid
RAID Recovery, but the more your unit’s capacity is under-utilized, the less
time a rebuild, initialization or verify will take if you enable Rapid RAID
Recovery.
Possible settings are All (labeled Fast Rebuild/Shutdown in 3BM) , Rebuild or
Disable . All will apply the policy to both rebuilds and unclean shutdowns.
Rebuild will apply only to rebuilds. Disable means that rebuilds,
initializations and verifies will take place on the entire unit, not just the active
sections. The default setting is
All .
There is some system overhead from setting rapid recovery to All . If you have
a BBU, you can set rapid recovery to Rebuild , as a BBU provides protection
against data loss in the event of an unclean shutdown.
Some limitations of Rapid RAID Recovery:
• Currently Rapid RAID Recovery only works with FAT, FAT32 and NTFS
file systems. Linux or FreeBSD file systems such as Ext3 are not yet
supported.