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Bug 1147258 - [Docs] Add detailed documentation explaining what the Actual size and Virtual size (UI columns) refer to
[Docs] Add detailed documentation explaining what the Actual size and Virtual...
Status: CLOSED CURRENTRELEASE
Product: Red Hat Enterprise Virtualization Manager
Classification: Red Hat
Component: Documentation (Show other bugs)
3.5.0
Unspecified Unspecified
unspecified Severity high
: ---
: 3.5.1
Assigned To: Lucy Bopf
Julie
storage
:
Depends On:
Blocks: 1200186
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Reported: 2014-09-28 10:39 EDT by Ori Gofen
Modified: 2016-05-25 21:49 EDT (History)
11 users (show)

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Doc Type: Bug Fix
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Last Closed: 2015-04-29 01:33:58 EDT
Type: Bug
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RHEL 7.3 requirements from Atomic Host:
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Description Ori Gofen 2014-09-28 10:39:02 EDT
1. Proposed title of this feature request

Add detailed documentation explaining what the Actual size and Virtual size (UI columns) refer to.

2. What is the nature and description of the request?

The main idea is to clear up this 2 concepts, so that alleviate any possible misunderstanding on the part of our end users (as well as any other internal users)

For example,The documentation should provide information that will answer:
what do these concepts mean?
what objects does "Virtual size" refer to? (is it an attribute that is added to disk, or to Volumes, or both)
How are these terms implemented on Block vs. File domain?

3. Why does the customer need this? (List the business requirements here)

Because I am unclear and thus the costumer may be completely baffled

4. Is there already an existing RFE upstream or in Red Hat Bugzilla?
no
Comment 1 Yaniv Lavi 2015-02-18 06:55:10 EST
This is on 3.5.0 and it is clearly not included, since there was not movement on this BZ. What is the status of this? can you please target this?
Comment 2 Lucy Bopf 2015-02-18 23:02:18 EST
Thanks for bringing this to my attention, Yaniv. I have updated the target release for docs, and assigned this to myself. I have begun to identify where this information should be included in the documentation.

If I understand correctly, the 'Virtual Size' column refers to the total amount of space that the disk can use (and is the number that you entered in 'Size(GB) when you created the disk), and the 'Actual Size' column refers to the amount of space that the disk has used at that point. If the disk is thinly provisioned, the user may see different values in each column. If the disk is preallocated, the user should see the same value in both.

Is that correct?
Comment 5 Lucy Bopf 2015-03-19 01:51:51 EDT
Thanks, Ori. I've updated the two references below:

"The Virtual Size of a disk is the total amount of disk space that the virtual machine can use; it is the number that you enter in the Size(GB) field when a disk is created. The Actual Size of a disk is the amount of disk space that has been allocated to the virtual machine so far." (in 'Understanding Virtual Disks')

"Virtual Size - The total size of the virtual disk used by the template. This value cannot be edited, and is provided for reference only. This value corresponds with the size, in GB, that was entered when the disk was created; if the disk is thinly provisioned, this value may differ from the actual amount of disk space that has been allocated to the virtual machine on which the template is based. (in 'Explanation of Settings and Controls in the New Template Window')

Do these changes make the disk space/VM relationship clearer?
Comment 6 Ori Gofen 2015-03-19 08:48:18 EDT
Ok, the first paragraph is almost true :)

"The Virtual Size of a disk is the total amount of disk space that the virtual machine can use; it is the number that you enter in the Size(GB) field when a disk is created." -> True

"The Actual Size of a disk is the amount of disk space that has been allocated to the virtual machine so far."-> this comment is mostly true, a floating disk which is not attached to any machine can also be created. so I would have edit this part to something like:

"The Actual Size of a disk is the amount of disk space that has been allocated to the virtual machine so far, or in case the disk was created as a floating disk, the actual size is the floating disk's size"

* note for the first paragraph: the virtual disk size can be extended via edit disk window.

Regarding the second paragraph, it is totally confusing could't understand if we are describing the actual size or the virtual size.

"Virtual Size - The total size of the virtual disk used by the template." <- this sentence does not make sense to me.

should be something like -> Virtual size(regarding templates of-course) is the total amount of disk space that a potential virtual machine can use in case it will be created from this template...this value cannot be edited etc.

The second part which does not make sense is:
"if the disk is thinly provisioned, this value may differ from the actual amount of disk space that has been allocated to the virtual machine on which the template is based"
If we mention that the this value is none editable and it is the size that was entered when the disk was created, how can it differ?
I think maybe there's a confusion, because it is describing the actual size but not the virtual size.

please contact me for more reference.
Comment 8 Ori Gofen 2015-03-23 07:11:28 EDT
looking good!

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