In the I/O Response Time Assurance Function, memory is used in each volume. For details, check the amount of memory required described in the installation guide.
When mirroring the internal disk, mirror the different disks of the path.
When mirroring the internal disk of the same path, the failure of the single disk may also affect other disks and delay the I/O.
When mirroring the system disk on a server such as SPARC M10 that has only one internal SAS controller, mirror the external disk as a system disk.
When using the storage device, connect the storage device to the server in order to satisfy the following conditions:
Connects using FC card or FCoE card.
Duplicates the path using ETERNUS Multipath Driver or MPxIO.
Duplicates the path using different controller module in storage.
Access paths for each storage LUN is configured as double paths.
When using FC swtich, use 2 FC swtiches.
When mirroring the disk of storage device, connect the 2 storage devices to the server to mirror (mirroring between units) the disk of the different unit.
When using multipath software, either use ETERNUS Multipath Driver or MPxIO. Using both for this configuration is not supported.
When using the ETERNUS disk, it is recommended to set the I/O response time value to 33 seconds or more.
If a value smaller than 33 seconds is set, the I/O may terminate by I/O Response Time Assurance Function before the path switches when an error of a single path of the multi-path occurs.
When using I/O Response Time Assurance Function with the environment that satisfies all of the following conditions, it is recommended to set the I/O response time to 36 seconds or more.
Use Emulex FC card.
Use ETERNUS Multipath Driver. Or, use MPxIO with the Solaris 10 environment.
If the time is set below 36 seconds with the above enviroment, the I/O may terminate by I/O Response Time Assurance Function when error occurs to only one of the FC paths.
In the system with mirror volume, it is recommended to set the system panic mode to disable for all the class with single volume.
When the system panic mode of I/O Response Time Assurance Function is set to enable for a class with single volume, the redundancy by mirroring has no effect, because the system will panic with just an occurrence of I/O error or I/O delay in only one storage unit.
In the ZFS mirror mode configuration, set the following to let the system panic when I/O error occurs on all of the volumes that configure ZFS storage pool and when the class is closed.
Set the failmode property of ZFS storage pool to panic.
Set the system panic mode of I/O Response Time Assurance Function to off.
When the system panic mode is set to on in a ZFS mirror mode configuration, since the system panics if an I/O error occurs on even one of the volumes making up the ZFS storage pool, the effect of the ZFS mirroring is lost.
Perform system operation test with the maximum load assumed in the system that uses this function, and depending on the system load check if I/O time out does not occur.
If using the following functions that affect I/O load during operation, use the following functions also to perform system operation test with the maximum load:
Synchronization copying of GDS
Advance Copy function of ETERNUS
