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October 2nd, 2014 10:00
Interesting symclone behavior
We have a VMAX 40K on Enginuity 5876, being managed by a Unisphere for VMAX vApp running SE 7.6.2. I have an AIX host with a dozen source TDEVs. From the vApp, I created a symclone session from the AIX source TDEVs to another batch of TDEVs, using just the source/target Symm Devs. Session ran just fine and completed with no issues.
Two weeks later, the AIX admin wants to create his own symclone session, using the same source TDEVs, but different destination TDEVs. He created a local device group on the host and attempted to activate it. He didn't get an error, but immediately saw my symclone target IDs, not his. In fact, every attempt to active his session completed successful, but only ran my session to my target TDEVs (as defined in my file), not his TDEVs (as defined by his device group).
We terminated my session, then his activation completed without any errors. I would expect either his symclone command from the host should have failed at the command line, or it should have re-established my session and updated the target devices with new data (the clone session was never activated from what I could tell).
Can someone explain this behavior?
Thanks!
seancummins
2 Intern
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226 Posts
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October 2nd, 2014 11:00
Karl,
I'd suggest giving it another try, but have your AIX administrator use the -exact flag against his device group when initially creating/activating his clone sessions. The -exact flag tells symclone to use the pairing relationships defined in the specified DG/CG/file, instead of reusing the existing clone sessions.
Thanks,
- Sean
dynamox
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October 2nd, 2014 11:00
is he experiencing the same behavior when he uses a file versus device group ?
umichklewis
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October 2nd, 2014 11:00
No, this was specific to the device group only. When using device files, each session worked without a problem. This was specifically activating his device group....
RHasleton1
73 Posts
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October 2nd, 2014 11:00
Karl,
Try setting the SYMAPI_COMMAND_SCOPE = ENABLE in the options file.
This tells the symclone command to only operate on the exact pairing specified in the device group. If you use a file, then this is not necessary, as it is being told explicitly which pairs to operate on.
Good luck,
Rick
https://support.emc.com/kb/57055
umichklewis
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October 2nd, 2014 12:00
Sure enough, Sean and RHaselton are spot on. When we call the symclone activate or recreate with the "-exact" flag, ew get the expected behavior. Without -exact, however, the activate only appears to look at the already-created session.
On another host, I tried RHaselton's suggestion and changed the daemon.options file. Sure enough, the symclone activate on the device group worked as expected.
But my admin and I want to know: why didn't the symclone just fail or report an error, instead of leading us to believe everything happened as expected? When I double-checked, it never ran his session, only mine. Had he attempted to vary on his volumes, he would have found nothing but empty disks.
Thanks for all the responses!
RHasleton1
73 Posts
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October 2nd, 2014 12:00
Here is the output from "symcli -env" and looking at the COMMAND_SCOPE explanation:
SYMCLI_COMMAND_SCOPE : Sets the scope of the device selection process.
ENABLED limits the operation to the devices within
the scope of the command. DISABLED performs the
operation on the devices within the scope of the
command plus any additional devices associated by
session and/or state. The default is DISABLED.
So by default, when trying to act upon a concurrent setup (single src, multiple tgt's), it will only report and act upon the currently associated tgt devices, since they are already associated with the source. It can be confusing if you've never used DG's with concurrent setups.
The only thing that puzzles me about your original question is usually when I try this, I get a message stating that the device(s) are already in the requested state (created or activated). It may be an order of operations thing there.
umichklewis
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October 3rd, 2014 07:00
Someone asked what the original issue was. Here's the device group we originally defined on the host:
U:\>symclone -g EPIC_PRD_BACKUP query -gb
Device Group (DG) Name: EPIC_PRD_BACKUP
DG's Type : REGULAR
DG's Symmetrix ID : 000195701234
Source Device Target Device State Copy
--------------------------------- ---------------------------- ------------ ----
Protected Modified Modified
Logical Sym (GB) (GB) Logical Sym (GB) CGDP SRC <=> TGT (%)
--------------------------------- ---------------------------- ------------ ----
EPIC_PRD* 03AF 0.0 0.0 EPIC_PRD* 047F 0.0 XXX. Copied 100
EPIC_PRD* 03B7 0.0 0.0 EPIC_PRD* 0487 0.0 XXX. Copied 100
EPIC_PRD* 03BF 0.0 0.0 EPIC_PRD* 048F 0.0 XXX. Copied 100
EPIC_PRD* 03C7 0.0 0.0 EPIC_PRD* 0497 0.0 XXX. Copied 100
EPIC_PRD* 03CF 0.0 0.0 EPIC_PRD* 049F 0.0 XXX. Copied 100
EPIC_PRD* 03D7 0.0 0.0 EPIC_PRD* 04A7 0.0 XXX. Copied 100
EPIC_PRD* 03DF 0.0 0.0 EPIC_PRD* 04AF 0.0 XXX. Copied 100
EPIC_PRD* 03E7 0.0 0.0 EPIC_PRD* 04B7 0.0 XXX. Copied 100
EPIC_PRD* 03EF 0.0 0.0 EPIC_PRD* 04BF 0.0 XXX. Copied 100
EPIC_PRD* 03F7 0.0 0.0 EPIC_PRD* 04C7 0.0 XXX. Copied 100
EPIC_PRD* 03FF 0.0 0.0 EPIC_PRD* 04CF 0.0 XXX. Copied 100
EPIC_PRD* 0407 0.0 0.0 EPIC_PRD* 04D7 0.0 XXX. Copied 100
EPIC_PRD* 040F 0.0 0.0 EPIC_PRD* 04DF 0.0 XXX. Copied 100
EPIC_PRD* 0417 0.0 0.0 EPIC_PRD* 04E7 0.0 XXX. Copied 100
EPIC_PRD* 041F 0.0 0.0 EPIC_PRD* 04EF 0.0 XXX. Copied 100
EPIC_PRD* 0427 0.0 0.0 EPIC_PRD* 04F7 0.0 XXX. Copied 100
EPIC_PRD* 0836 0.0 0.0 EPIC_PRD* 083E 0.0 XXX. Copied 100
EPIC_PRD* 042F 0.0 0.0 EPIC_PRD* 0507 0.0 XXX. Copied 100
EPIC_PRD* 0433 0.0 0.0 EPIC_PRD* 050B 0.0 XXX. Copied 100
EPIC_PRD* 0437 0.0 0.0 EPIC_PRD* 050F 0.0 XXX. Copied 100
EPIC_PRD* 043B 0.0 0.0 EPIC_PRD* 0513 0.0 XXX. Copied 100
EPIC_PRD* 043F 0.0 0.0 EPIC_PRD* 0517 0.0 XXX. Copied 100
EPIC_PRD* 0443 0.0 0.0 EPIC_PRD* 051B 0.0 XXX. Copied 100
EPIC_PRD* 0447 0.0 0.0 EPIC_PRD* 051F 0.0 XXX. Copied 100
Total -------- -------- --------
GB(s) 0.0 0.0 0.0
Looks okay to me. So, we set the daemon options flag SYMAPI_ALLOW_DEV_IN_MULT_GRPS = ENABLE, so that we can take the same source devices, and put them into multiple device groups. Then, we tried to establish a clone on the other device group:
U:\>symclone -g EPIC_PRD_BACKUP query -gb
Device Group (DG) Name: EPIC_PRD_BACKUP
DG's Type : REGULAR
DG's Symmetrix ID : 000195701234
Source Device Target Device State Cop
--------------------------------- ---------------------------- ------------ ---
Protected Modified Modified
Logical Sym (GB) (GB) Logical Sym (GB) CGDP SRC <=> TGT (%)
--------------------------------- ---------------------------- ------------ ---
EPIC_PRD* 03AF 149.1 0.0 N/A 0677 0.0 X.X. CopyInProg 62
EPIC_PRD* 03B7 93.0 0.0 N/A 067F 0.0 X.X. CopyInProg 76
EPIC_PRD* 03BF 237.4 0.0 N/A 0687 0.0 X.X. CopyInProg 40
EPIC_PRD* 03C7 239.4 0.0 N/A 068F 0.0 X.X. CopyInProg 40
EPIC_PRD* 03CF 148.8 0.0 N/A 0697 0.0 X.X. CopyInProg 62
EPIC_PRD* 03D7 94.3 0.0 N/A 069F 0.0 X.X. CopyInProg 76
EPIC_PRD* 03DF 239.0 0.0 N/A 06A7 0.0 X.X. CopyInProg 40
EPIC_PRD* 03E7 239.6 0.0 N/A 06AF 0.0 X.X. CopyInProg 40
EPIC_PRD* 03EF 149.8 0.0 N/A 06B7 0.0 X.X. CopyInProg 62
EPIC_PRD* 03F7 93.3 0.0 N/A 06BF 0.0 X.X. CopyInProg 76
EPIC_PRD* 03FF 239.0 0.0 N/A 06C7 0.0 X.X. CopyInProg 40
EPIC_PRD* 0407 240.6 0.0 N/A 06CF 0.0 X.X. CopyInProg 39
EPIC_PRD* 040F 148.4 0.0 N/A 06D7 0.0 X.X. CopyInProg 62
EPIC_PRD* 0417 93.8 0.0 N/A 06DF 0.0 X.X. CopyInProg 76
EPIC_PRD* 041F 239.1 0.0 N/A 06E7 0.0 X.X. CopyInProg 40
EPIC_PRD* 0427 239.9 0.0 N/A 06EF 0.0 X.X. CopyInProg 40
EPIC_PRD* 0836 240.2 0.0 N/A 0A0E 0.0 X.X. CopyInProg 39
EPIC_PRD* 042F 0.0 0.0 EPIC_PRD* 0507 0.0 XXX. Copied 100
EPIC_PRD* 0433 0.0 0.0 EPIC_PRD* 050B 0.0 XXX. Copied 100
EPIC_PRD* 0437 0.0 0.0 EPIC_PRD* 050F 0.0 XXX. Copied 100
EPIC_PRD* 043B 0.0 0.0 EPIC_PRD* 0513 0.0 XXX. Copied 100
EPIC_PRD* 043F 0.0 0.0 EPIC_PRD* 0517 0.0 XXX. Copied 100
EPIC_PRD* 0443 0.0 0.0 EPIC_PRD* 051B 0.0 XXX. Copied 100
EPIC_PRD* 0447 0.0 0.0 EPIC_PRD* 051F 0.0 XXX. Copied 100
Total -------- -------- --------
GB(s) 3124.8 0.0 0.0
What the heck? Symclone is now looking at the already-in-progress symclone session, not the devices defined in the device group.
RHasleton has the exact solution to this problem: SYMAPI_COMMAND_SCOPE = ENABLE
Enabling this flag, causes the SYMCLI commands to only look at my device group:
U:\>symclone -g EPIC_PRD_BACKUP query -gb
Device Group (DG) Name: EPIC_PRD_BACKUP
DG's Type : REGULAR
DG's Symmetrix ID : 000195701234
Source Device Target Device State Copy
--------------------------------- ---------------------------- ------------ ----
Protected Modified Modified
Logical Sym (GB) (GB) Logical Sym (GB) CGDP SRC <=> TGT (%)
--------------------------------- ---------------------------- ------------ ----
EPIC_PRD* 03AF 0.0 0.0 EPIC_PRD* 047F 0.0 XXX. Copied 100
EPIC_PRD* 03B7 0.0 0.0 EPIC_PRD* 0487 0.0 XXX. Copied 100
EPIC_PRD* 03BF 0.0 0.0 EPIC_PRD* 048F 0.0 XXX. Copied 100
EPIC_PRD* 03C7 0.0 0.0 EPIC_PRD* 0497 0.0 XXX. Copied 100
EPIC_PRD* 03CF 0.0 0.0 EPIC_PRD* 049F 0.0 XXX. Copied 100
EPIC_PRD* 03D7 0.0 0.0 EPIC_PRD* 04A7 0.0 XXX. Copied 100
EPIC_PRD* 03DF 0.0 0.0 EPIC_PRD* 04AF 0.0 XXX. Copied 100
EPIC_PRD* 03E7 0.0 0.0 EPIC_PRD* 04B7 0.0 XXX. Copied 100
EPIC_PRD* 03EF 0.0 0.0 EPIC_PRD* 04BF 0.0 XXX. Copied 100
EPIC_PRD* 03F7 0.0 0.0 EPIC_PRD* 04C7 0.0 XXX. Copied 100
EPIC_PRD* 03FF 0.0 0.0 EPIC_PRD* 04CF 0.0 XXX. Copied 100
EPIC_PRD* 0407 0.0 0.0 EPIC_PRD* 04D7 0.0 XXX. Copied 100
EPIC_PRD* 040F 0.0 0.0 EPIC_PRD* 04DF 0.0 XXX. Copied 100
EPIC_PRD* 0417 0.0 0.0 EPIC_PRD* 04E7 0.0 XXX. Copied 100
EPIC_PRD* 041F 0.0 0.0 EPIC_PRD* 04EF 0.0 XXX. Copied 100
EPIC_PRD* 0427 0.0 0.0 EPIC_PRD* 04F7 0.0 XXX. Copied 100
EPIC_PRD* 0836 0.0 0.0 EPIC_PRD* 083E 0.0 XXX. Copied 100
EPIC_PRD* 042F 0.0 0.0 EPIC_PRD* 0507 0.0 XXX. Copied 100
EPIC_PRD* 0433 0.0 0.0 EPIC_PRD* 050B 0.0 XXX. Copied 100
EPIC_PRD* 0437 0.0 0.0 EPIC_PRD* 050F 0.0 XXX. Copied 100
EPIC_PRD* 043B 0.0 0.0 EPIC_PRD* 0513 0.0 XXX. Copied 100
EPIC_PRD* 043F 0.0 0.0 EPIC_PRD* 0517 0.0 XXX. Copied 100
EPIC_PRD* 0443 0.0 0.0 EPIC_PRD* 051B 0.0 XXX. Copied 100
EPIC_PRD* 0447 0.0 0.0 EPIC_PRD* 051F 0.0 XXX. Copied 100
Total -------- -------- --------
GB(s) 0.0 0.0 0.0
This was pretty unnerving, since we thought we just lost weeks worth of data!
Hopefully, this will be useful to someone else who runs into this issue. Thanks for all the suggestions and help from everyone!
Karl