For errors related to the Dell EMC storage units, in one of the following circumstances, take action as indicated for the relevant situation.
(1) SRDF is not used in master-to- proxy synchronization copying.
Explanation
The method handling master-to-proxy copying can be checked in the CPTYPE field that is displayed with the sdxinfo command. When the CPTYPE field displays soft without displaying SRDF, instead of SRDF, the GDS soft copy function is performing the copy operation.
The following five possible causes can create a situation where SRDF is not used.
The configuration of the master or proxy group is inappropriate.
The source (R1) and target (R2) devices as the SRDF pair must be connected with the master and proxy groups respectively. With the proxy group, the target (R2) device only must be connected.
A pair of volumes, instead of a pair of groups, was related as the master and the proxy.
When joining the master and the proxy groups, the specific was set to create proxy volumes to the proxy group with the physical slice attributes that are different from those of the master volumes.
Master data was restored using the proxy with the sdxproxy RejoinRestore command.
When the sdxproxy RejoinRestore command performs master restoration, the SRDF pair is cancelled and SRDF becomes no longer available.
With the sdxproxy Join command or the sdxproxy Rejoin command, the -e option was specified to use the soft copy function.
When the -e softcopy option is specified with the sdxproxy Join command, SRDF is not used.
When the -e softcopy option is specified with the sdxproxy Rejoin command, the SRDF pair is cancelled and SRDF becomes no longer available.
For details, see "A.2.27 Using Dell EMC TimeFinder or Dell EMC SRDF in a Proxy Configuration."
Resolution
1) Check whether the possible cause is (Cause a).
1-1) Identify the physical disk names of the disks connected with the master and the proxy groups.
# sdxinfo -D -o mg1 # sdxinfo -D -o pg1 |
In this example, the physical disks emcpower10 and emcpower11 have been connected with the master group mg1, and the physical disk emcpower20 has been connected with the proxy group pg1.
If a lower level group is, or multiple disks or lower level groups are, connected with the proxy group, the possible cause is (Cause a).
1-2) Identify the Symmetrix IDs and the Symmetrix device names of the disks connected with the master and the proxy groups using the sympd command provided by SYMCLI.
# sympd list |
In this example, as to the physical disks emcpower10c and emcpower11c, the Symmetrix ID is 000183600262 and the Symmetrix device names are 000 and 001 respectively. As for the physical disk emcpower20c, the Symmetrix ID is 000282600920 and the Symmetrix device name is 005.
See
For details on the sympd command, see the Symmetrix Manager manual.
1-3) Check the source (R1) device and the target (R2) device as the SRDF pair whether they are connected with the master and proxy groups respectively using the symrdf command provided by SYMCLI.
The SymDev field and the RDev field of the symrdf list command output display the Symmetrix device names of the source (R1) device and the corresponding target (R2) device respectively.
# symrdf list ... Symmetrix ID: 000282600920
Local Device View
-------------------------------------------------------------------------------
STATUS M O D E S RDF S T A T E S
Sym RDF --------- ------------ R1 Inv R2 Inv -----------------------
Dev RDev Typ:G SA RA LNK Mode Dom ACp Tracks Tracks Dev RDev Pair
--- ---- ----- --------- ------------ ------ ------ --- ---- --------------
...
005 000 R2:1 RW RW NR SYN DIS OFF 0 0 RW RW Synchronized
006 002 R1:2 RW RW NR SYN DIS OFF 0 0 RW RW Split
... |
In this example, the source (R1) device 000 in the Symmetrix frame 000183600262 and the target (R2) device 005 in the Symmetrix frame 000282600920 are the SRDF pair. The master and the proxy have been configured properly, and the possible cause is not (Cause e).
See
For details on the symrdf command, see the Symmetrix Manager manual.
1-4) If the possible cause is (Cause e), release the master-proxy relationship once, and re-configure properly.
For example, according to the symrdf command results in step 1-3), you will see that the source (R1) device 006 in the Symmetrix frame 000282600920 and the target (R2) device in the Symmetrix frame 000183600262 are also the SRDF pair. The sympd command results in step 1-2) are indicating that the physical disk names of the Symmetrix devices 006 and 002 are emcpower21 and emcpower12 respectively. The proxy configuration associated with SRDF can be created by registering emcpower21 and emcpower12 with a class, connecting them with respective groups, and relating the groups as the master and proxy.
In addition, the registration of the source (R1) device with a device group can be done after registering the disk with a class, but it must be carried out before joining the master and the proxy.
2) Check whether the possible cause is (Cause b).
In this example, the MASTER field of the group pg1 to which the proxy volume pv1 belongs displays the asterisk (*) and the MASTER field of pv1 displays the master volume name mv1, and the possible cause is (Cause b).
If the possible cause is (Cause b), the action as follows should be implemented.
2-1) Break the relationship between the master and proxy volumes.
# sdxproxy Break -c Class1 -p pv1 |
2-2) Join a pair of groups instead of a pair of volumes as the master and the proxy. In this example, the master group name is mg1.
# sdxproxy Join -c Class1 -m mg1 -p pg1 -a mv1=pv1:on |
3) Check whether the possible cause is (Cause c).
In this example, the attributes of the physical slices of the master volume mv1 and the proxy volume pv1 are on and off respectively, and the possible cause is (Cause c).
If the possible cause is (Cause c), the action as follows should be implemented.
3-1) Break the master-proxy relationship.
# sdxproxy Break -c Class1 -p pg1 |
3-2) Relate the master and the proxy again. With the -a option for the sdxproxy Join command, if the physical slice attribute is not specified, the physical slice attribute of a created proxy volume conforms to that of the master volume.
# sdxproxy Join -c Class1 -m mg1 -p pg1 -a mv1=pv1:on |
4) Whether the possible cause is (Cause d) or (Cause e) can be determined by checking the command action history referencing the GDS log file /var/opt/FJSVsdx/msglog/sdxservd.log.
If the possible cause is (Cause d) or (Cause e), the master and the proxy should be disjoined once and then rejoined.
(2) The joined proxy volume is in INVALID status.
Explanation
TimeFinder and SRDF may stop operating because the exclusive lock on a Symmetrix device is not released due to an event such as a node down. In this event, copying by TimeFinder or SRDF does not operate normally, and the proxy volume status may become INVALID.
The exclusive locks for Symmetrix devices are divided into two types. Whether respective exclusive locks are left not released can be checked using the symdev and symcfg commands provided by SYMCLI.
# symdev -lock list |
If an exclusive lock has remained, the lock number is displayed.
Resolution
Release the exclusive lock on the Symmetrix device with the following method.
As to an exclusive lock indicated by the symdev -lock list command, use the symdev command to release it. Substitute the lock number displayed with the symdev -lock list command for number.
# symdev -lock number release |
As to an exclusive lock indicated by the symcfg -lock list command, use the symcfg command to release it. Substitute the lock number displayed with the symcfg -lock list command for number.
# symcfg -lockn number release |
See
For details on the symdev command and the symcfg command, see the Symmetrix Manager manual.
