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Re: Problem Adding Volume to Replication Group: Zero_detect Disabled?

 
Sheldon Smith
HPE Pro

Re: Problem Adding Volume to Replication Group: Zero_detect Disabled?

<grumble grumble mutter mutter>

 

This is an old recommendation from back in the T and F days.

It is not a problem with any of the StoreServ generation.

 

I have been applying boots to the head to start getting documentation updated.

 

Turn zero_detect on.


Note: While I am an HPE Employee, all of my comments (whether noted or not), are my own and are not any official representation of the company

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L1nklight
Valued Contributor

Re: Problem Adding Volume to Replication Group: Zero_detect Disabled?

Any input on that error message I recieved when trying to enable zero_detect on the tdvv?

 

3PAR7450 cli% setvv -pol zero_detect Volume_Name
Error: VV Volume_Name is a TDVV and thus cannot have zero_detect policy enabled
3PAR7450 cli%

Sheldon Smith
HPE Pro

Re: Problem Adding Volume to Replication Group: Zero_detect Disabled?

TDVVs do zero detect in a different way. All zero pages will dedup to a single page so there’s no need to have the extra zero detection of TPVVs.

If you try to set zero_detect on a TDVV you will get an error.

 

So:

TPVV, policy zero_detect yes

TDVV, policy zero_detect no

 

 

Note: While I work for HP, all of my comments (whether noted or not), are my own and are not any official representation of the company.
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Note: While I am an HPE Employee, all of my comments (whether noted or not), are my own and are not any official representation of the company

Accept or Kudo

L1nklight
Valued Contributor

Re: Problem Adding Volume to Replication Group: Zero_detect Disabled?

That makes sense! Thanks so much. It very strange though. I've tested it and if you create a TDVV volume through the GUI it will be set to zero_detect. The volumes in question that have no_zero_detect I created via a script without the zero_detect argument. I have all TDVV volumes so essentially what you see when you look at the volumes is a mix of tdvv volumes with zero_detect and no_zero_detect.

 

Thanks for your answer. I appreciate your help!

Dennis Handly
Acclaimed Contributor

Re: Problem adding VV to Replication Group: Zero_detect Disabled?

> if you create a TDVV volume through the GUI it will be set to zero_detect.

 

It might be due to the difference in checking between createvv and setvv.

Sheldon Smith
HPE Pro

Re: Problem adding VV to Replication Group: Zero_detect Disabled?

Suggest you download the latest Management Console (MC 4.6.2) as well as the new StoreServ Management Console (SSMC 2.0).

 

Both are available today at the HP Software Depot:

https://h20392.www2.hp.com/portal/swdepot/displayProductsList.do?category=3PAR

 

 


Note: While I am an HPE Employee, all of my comments (whether noted or not), are my own and are not any official representation of the company

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L1nklight
Valued Contributor

Re: Problem adding VV to Replication Group: Zero_detect Disabled?

Already done! I was on the closed release for the GA. The create volume operation went perfectly and there were no issues. So far I really like the SSMC and it seems to bring HP more in line with its competitors as far as look and feel (Pure and Xtreme I/O).

 

The volume has been created and no_zero_detect was the default on the tdvv volume. It must be something with the way the volume is created in the GUI or in the GUI for 3.2.1 MU1 vs. changing an attribute on the policy after creation.

 

All of the tdvv volumes I created using the java based GUI on version 3.2.1 MU1 seemed to have been created with zero_detect enabled. All the volumes I created using the CLI for version 3.2.1 MU1 seemed to have been created wtih no_zero_detect enabled which appears to be a CLI default setting. Under version 3.2.1 MU2 the volume I created using the SSMC v2.0 was created with no_zero_detect.

 

As a test I went ahead and ran setvv to change the policy on one of my tdvvs from zero_detect to no_zero_detect and then tried to move it back to zero_detect. As expected, the system wouldn't let me change it back to zero_detect. This was as discussed on this thread.

 

Thanks for your help.

NicholasSullo
Occasional Contributor

Re: Problem adding VV to Replication Group: Zero_detect Disabled?

I'm a little confused.  All my TDVVs are no_zero_detect and this is normal right?  If so, why did it sometimes put yours as zero_detect with a different client if it's something that's not needed?  Is this something I should be worried about because I'm doing some VMWARE vMotions of some of my disks and they seem to be taking quite long as if they aren't detecting zeros?

Dennis Handly
Acclaimed Contributor

Re: Problem adding VV to Replication Group: Zero_detect Disabled?

>if it's something that's not needed?

 

I wouldn't worry.  Both the zero-detect and de-dup code use the ASIC hardware, so de-dup is a superset of zero-detect.