Performing CCI Operations
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Hitachi AMS 2000 Family Command Control Interface (CCI) Reference Guide
• Port#, targ#, lun#: Shows the port number, target ID, and LU
number as described in the configuration definition file.
• LDEV#: Shows the logical device number. LDEV indicates LU.
• P/S: Shows the volume attribute.
• Status: Shows the status of the paired volume.
• Fence: Shows the fence level.
• To be...: Evaluating the mirror consistency of S-VOL shows the
currency of the volume.
Performing takeover operations (horctakeover)
•
The horctakeover command is a scripted command for executing several
HORC operations. The horctakeover command checks the specified
volume’s or group’s attributes (paircurchk), decides the takeover function
based on the attributes, executes the chosen takeover function, and returns
the result. The four TrueCopy takeover functions designed for HA software
operation are: takeover-switch, swap-takeover, PVOL-takeover, and SVOL-
takeover. TCE takeover function designed for HA software operation is
SVOL-takeover only. A paired volume or a group can be specified as the
target of the TrueCopy or TCE horctakeover command. If TrueCopy or TCE
SVOL-takeover is specified for a group, the data consistency check is
Note 1: When the array to be used is changed to the remote one by the
horctakeover command, the local array is placed in the PSUE status
depending on the time when the change is made because of a collision with
an I/O instruction issued by a host to the local array. This status transition
occurs because the change is untimely. However, even if this occurs,
reading to and writing from an S-VOL of the remote array can be done
because the horctakeover command keeps the S-VOL in the PSUS status
(SSWS).
Note 2: In the case of TrueCopy, when the horctakeover command is
issued to the remote array, there may be a rare case where the SWAP-
Takeover fails and terminates in the SVOL-Takeover status because of a
load of the other CCI command on the local array added to a load of the
horctakeover command. However, even if this occurs, the S-VOL is kept in
the PSUS status (SSWS) and reading to it and writing from it can be done.
Besides, a swap between a primary and secondary volume can be done
when it is possible after statuses of the local and remote arrays are checked
and the pairresync –swaps command is executed for the remote array.
Note 3: When the –d option is specified in the case of TCE, only an S-VOL
of the target pair is placed in the SSWS status. Besides, at this time, all the
other pairs in the same CTG are not kept paired. When a P-VOL was in the
PAIR status before the command was accepted, it is placed in the PSUE
status because the pair created of it and an S-VOL is split forcibly. On the
other hand, statuses of the other S-VOLs in the CTG are not changed and
kept as PAIR because the communication from the primary array is cut off
Summary of Contents for AMS 2000 Series
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