Hitachi VSP G200 System Administration Manual page 354

Mode Category
144 Common
354
System Administrator Guide for VSP Gx00 models and VSP Fx00 models
Description
the threshold, which mitigates the occurrence possibility of
the host time-out.
Mode 142 = ON (default*): The threshold value of
blocking a drive port due to command time-out is changed to
the half of the normal threshold.
Mode 142 = OFF: The threshold value of blocking a drive
port due to command time-out does not change.
*The default setting for this SOM depends on the microcode
level:
• Default = ON: , 83-03-28 and later (within 83-03-2x
range), 83-04-03 and later
• Default = OFF: , earlier than 83-03-28, earlier than
83-04-03 (within 83-04-0x range)
Notes:
1. This SOM should always be set to ON. This SOM can be
set to OFF only when the customer does not allow to
set this SOM to ON for a storage system already in
production.
2. This SOM is effective for the entire storage system.
The drive whose command response time is permanently
delayed is blocked. At the same time, SSB=AE4A (total
response time exceeds threshold) is reported. In this case,
cache can become overloaded so that the storage system
performance is degraded.
Mode 144 = ON (default*): Check if there is a
permanently delayed drive for each port, and block the
corresponding port at the first time when all of the following
conditions are met:
1. The total time for the drive to respond to 200
commands is 20 seconds or more.
2. The response time of the drive is two times or more
longer than the average response time of the parity
group (excluding the slow drive).
3. The drive is in one of the following statuses:
- Normal
- A source drive or a target drive (spare drive) during
drive copy.
- A target drive (not spare drive) during copy back.
- A target drive (spare drive) during correction copy.
Mode 144 = OFF: Checking for delayed drives is not
performed.
*The default setting for this SOM depends on the microcode
level:
• Default = ON: 80-04-27 and later (within 80-04-xx
range), 80-05-05 and later, 83-03-28 and later (within
83-03-2x range), 83-04-03 and later
• Default = OFF: earlier than 80-04-27 (within 80-04-xx
range), earlier than 80-05-05 (within 80-05-0x range),
earlier than 83-03-28, earlier than 83-04-03 (within
83-04-0x range)
System option modes
Default MCU/RCU
ON -