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What does thin provisioned settings mean?

Hi,

I have a 20GB LUN that is almost 8G busy.

In-use: Is the space already occupied
Free: It's free space, but in relation to what size? At 20GB?
Unreserved: What is it? When will it be used?

When I drag the LUN boundary margins, I realize that these numbers change. Is it merely a visual configuration or intefere in the size of the LUN?

I realize that when I change the minimum threshold margin the maximum growth size of the LUN changes as well. What is the relation of this limit with the maximum of growth?

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Re: What does thin provisioned settings mean?

Hello, 

 In-use is how much has been written to so far. 

 Free: is a preallocated buffer so that new writes don't suffer any penalty. 

 Unreserved:  Is the rest of the volume that hasn't been used yet.  That's how much you are "saving" current.  That unreserved space can be used by any volume or snapshot.  So as you write more to the volume, that unreserved space will go down in in-use space will increase. 

 The first slider allows you to increase that pre-allocated "free" space. 

The 2nd (middle) slider is a warning threshold.  Default 60%.  With thin provisioned volumes it's possible to over allocate your storage.  So this gives the admin an alert as space is used on your thin provisioned volumes.  

The 3rd (last slider) allows you to set the maximum amount of space the volume can use before sending an error to the server.  This is if you know you have over allocated your storage but plan on adding more later. 

 http://psonlinehelp.dell.com/V10.0/GUID-9FAC1640-BD0E-4BCD-9AEC-83CB03032128.html

 This link has some more info on thin provisioning as well.  

 Regards,

Don

 

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Re: What does thin provisioned settings mean?

Hello, 

 There are some videos that might also help you with Equallogic features

https://www.youtube.com/user/TechSupportDell/search?query=equallogic

 Regards, 

Don 

 

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Re: What does thin provisioned settings mean?

Okay, I understood what you said in theory. But in practice not yet.

Does the slider allow interfering with the operating system's use of the allocated tauntal LUN space? Or does it only help in "alarm" administration to know that there is a growth of the LUN?

A 650GB LUN. After enabling thin provisioning, it did.

- 314GB in use, that is, already have data written to the LUN.
- 9GB is free, that is, as you said, is available for use to avoid delays in use.
- 325GB is not reserved.

The margin controls (10%, 60% and 100%) are in the standard.

When it reaches 60% it will generate a warning on the LUN, but the data will continue to be written without any interference.

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Re: What does thin provisioned settings mean?

Hello, 

 You are correct.  The 60% is the default warning threshold. It will generate warning messages only when that threshold is exceeded.   You can change that at any time. 

It's just a tool to help the admin monitor capacity used. 

Reminder, as files are deleted the in-use space only goes down if the host OS sends the UNMAP command.  So depending on what version of Windows that may not happen automatically.  W2K12+ support it.  Windows 2K8 can if you install the Host Integration Toolkit/Microsoft Edition  (HIT/ME).   that's available on the eqlsupport.dell.com website if you have an active contract on your array. 

Regards, 

Don

 

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