Unfortunatly I can answer only your first question, since I don't know any "DMX concept guide"
The VCMDB is a "database" that the Symmetrix uses when an host "knocks" on its doors... Given the WWN of the host, the Symmetrix will lookup in the VCMDB a lot of usefull informations like the Masking, the lun-offset, the hba_flags and so on .. It's mainly used to answer the question "Which host can see which device?" (masking). Since DMX3 VCMDB sits into SFS (a reserved area on the disks) while before it was on a specific device (the VCMDB device). In both cases it's on the disks inside the storage. You can query and modify this special database with the "symmask" and "symmaskdb" commands.
The SYMAPI database is a repository that our Solution Enabler (the base software that includes also "symmask" and "symmaskdb") creates on every host where the software is installed. It holds informations about the storages a host can see. Informations like the number of drives in the backend, the layout of the slices on the disks, the number of ports and their configuration and so on .. It's in a directory of the host (/var/symapi/config or c:\progra files\emc\symapi\config) and you use "symcfg discover" to rebuild this database. Almost every other Symcli (Solution Enabler) command will use this database.
Thanks for the answer Stefano, that is a helpful answer. As a symmetrix newbie I was getting ready to ask the same question.
Jason, The following documents have helped answer a lot of my questions about the DMX platform. They are all at: Support > Technical Documentation and Advisories > Software ~ S ~ Documentation > Solutions Enabler > General Reference "EMC Symmetrix DMX-4 Product Guide" "EMC Solutions Enabler Symmetrix Array Management CLI Product Guide" "EMC Solutions Enabler Symmetrix Array Controls CLI Product Guide"
The last one has a section on device masking that mentions the VCMDB, but it was not as concise and to the point as Stefano's answer
I have one question here. If I issue Symmaskdb, which database, the command will be routed to. It will routed to the Symapi database or VCMDB database.
Explanation you gave is very clear and good.
I appreciate your great involvement in answering the customer queries.
Naren, as Dynamox said (ipse dixit! ) symmask and symmaskdb commands work mainly on the VCMDB .. But they read some informations even from symapi_db.bin since they (the commands) needs to find the size of the devices (just to make an example).
xe2sdc
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October 2nd, 2007 16:00
The VCMDB is a "database" that the Symmetrix uses when an host "knocks" on its doors... Given the WWN of the host, the Symmetrix will lookup in the VCMDB a lot of usefull informations like the Masking, the lun-offset, the hba_flags and so on .. It's mainly used to answer the question "Which host can see which device?" (masking). Since DMX3 VCMDB sits into SFS (a reserved area on the disks) while before it was on a specific device (the VCMDB device). In both cases it's on the disks inside the storage. You can query and modify this special database with the "symmask" and "symmaskdb" commands.
The SYMAPI database is a repository that our Solution Enabler (the base software that includes also "symmask" and "symmaskdb") creates on every host where the software is installed. It holds informations about the storages a host can see. Informations like the number of drives in the backend, the layout of the slices on the disks, the number of ports and their configuration and so on .. It's in a directory of the host (/var/symapi/config or c:\progra files\emc\symapi\config) and you use "symcfg discover" to rebuild this database. Almost every other Symcli (Solution Enabler) command will use this database.
AranH1
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October 3rd, 2007 07:00
Jason,
The following documents have helped answer a lot of my questions about the DMX platform. They are all at:
Support > Technical Documentation and Advisories > Software ~ S ~ Documentation > Solutions Enabler > General Reference
"EMC Symmetrix DMX-4 Product Guide"
"EMC Solutions Enabler Symmetrix Array Management CLI Product Guide"
"EMC Solutions Enabler Symmetrix Array Controls CLI Product Guide"
The last one has a section on device masking that mentions the VCMDB, but it was not as concise and to the point as Stefano's answer
-Aran
naren23-3_uew
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October 3rd, 2007 11:00
I have one question here. If I issue Symmaskdb, which database, the command will be routed to. It will routed to the Symapi database or VCMDB database.
Explanation you gave is very clear and good.
I appreciate your great involvement in answering the customer queries.
dynamox
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October 3rd, 2007 13:00
naren23-3_uew
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October 3rd, 2007 16:00
xe2sdc
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October 4th, 2007 01:00
jasonj1
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October 4th, 2007 06:00
xe2sdc
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October 4th, 2007 06:00
answer. As a symmetrix newbie I was getting ready to
ask the same question.
We'll be glad to try to answer almost every question
8<--8<--8<
mentions the VCMDB, but it was not as concise and to
the point as Stefano's answer
When you have good questions, you can give good answers .. when you have poor questions sometime it's almost impossible even to answer
-s-
Message was edited by:
Stefano Del Corno