multiple entries in the ESM firmware download window for ESM firmware
download, you must quiesce I/O operations from the host servers before you
start the ESM firmware download process.
Note:
Even though the storage subsystem supports controller and ESM
firmware upgrade while the storage subsystem processes I/O from the host
server, schedule controller and ESM firmware upgrades to occur during time
periods of low I/O between the storage subsystems and host servers.
3.
Upgrade the controller firmware and NVSRAM. See Table 2 on page 5 and step
1 on page 6.
Note:
See the readme file in the DS Storage Manager controller firmware
package that is associated with the applicable host operating system
environment for a support statement about the concurrent controller firmware
download .
Attention:
Before you upgrade the controller firmware, see the readme file that
comes with the firmware for any special prerequisite tasks, ESM firmware, and
stepping-stone controller firmware that must be installed before the controller can
be upgraded. Failure to do so might result in loss of data availability. There are
certain minimum controller firmware level requirements that are associated with
various storage enclosures. See “Intermixing storage enclosures” on page 11,
“Intermixing storage enclosures” on page 11, and “Intermixing storage enclosures”
on page 11 for related information.
Drive migration limitations
In general, drives with existing data and logical drives configuration can be
migrated between storage subsystems that have the same level of controller
firmware installed or from a source storage subsystem that has an older version of
controller firmware installed than the one installed in the destination storage
subsystem. However, it is a best practice to limit the drive migration between
storage subsystems of the same level of controller firmware. The reason is that
different versions of controller firmware might implement different metadata
(DACstore) data structures to store the logical drive information. These metadata
(DACstore) data structures are not interchangeable. If a newer version of controller
firmware changes the metadata structure, all of the controller firmware versions
older than this controller firmware cannot decode the metadata structure to obtain
the logical drive information in the migrated drives and recreate them in the
destination storage subsystem. But, this newer version of controller firmware
normally includes the code to decode the previous metadata structure that it
changes to allow the migration of the drives in the storage subsystem with older
version of controller firmware. For more information about drive migration
limitations based on controller firmware levels, see Table 4 on page 8.
Only the logical drive and array definitions along with their data can be migrated
between storage subsystems. The Host-to-LUN mappings and the configuration
definition and data of the copy services premium features like FlashCopy,
VolumeCopy and Remote Mirroring must be removed prior to drive migration.
Depending on the version of the installed controller firmware, the LUN mappings
and the copy service configuration information can be saved in script file so that
they can be recreated in the destination storage subsystem. If the drives with data
cannot be migrated to the destination storage subsystem, one has to backup the
data in those drives to a different medium like tape and then restores the data into
the destination storage subsystem.
Chapter 1. Prerequisites to adding capacity and hard disk drive migration
7
Summary of Contents for System Storage DCS Series
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