Bug 770970 - lvm2 man page and documentation for "normal" Allocation Policy needs to be improved
lvm2 man page and documentation for "normal" Allocation Policy needs to be im...
Product: Red Hat Enterprise Linux 5
Classification: Red Hat
Component: lvm2 (Show other bugs)
All Linux
high Severity high
: rc
: ---
Assigned To: Alasdair Kergon
Cluster QE
: Documentation, ManPageChange
Depends On:
Blocks: 743405
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Reported: 2011-12-30 11:04 EST by Luca Villa
Modified: 2013-01-08 02:11 EST (History)
13 users (show)

See Also:
Fixed In Version: lvm2-2.02.88-10.el5
Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of:
: 796977 796978 (view as bug list)
Last Closed: 2013-01-08 02:11:42 EST
Type: ---
Regression: ---
Mount Type: ---
Documentation: ---
Verified Versions:
Category: ---
oVirt Team: ---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---

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Description Luca Villa 2011-12-30 11:04:12 EST
Description of problem:
Documentation describing lvm2 "normal" allocation policy is not very comprehensive and needs to be improved in order to allow the reader to be fully aware about how the extents of a logical volume are allocated.

Version-Release number of selected component (if applicable):

How reproducible:

Steps to Reproduce:
Actual results:
This is the only description available about how normal policy works in the man page:
"The default for a volume group is normal which applies common-sense rules such as not placing parallel stripes on the same physical volume"
In the Logical Volume Manager Administration guide the description is pretty the same.

Expected results:
A more comprehensive description about how extents are allocated throughout PVs possibly with details and examples.

Additional info:
The same applies to RHEL6 as well.
Comment 1 Alasdair Kergon 2012-03-07 15:11:40 EST
Yes, we can provide more-detailed documentation.

To cover:
  - How the set of 'available' extents is generated (command line, existing space)
  - Outline of the process and how the --alloc policy affects it
  - Rules for 'parallel' extents (mirror, stripes)
    - Description of each policy

Not to cover specific implementation details (i.e. the bits that are not guaranteed and might change from release to release)
Comment 2 RHEL Product and Program Management 2012-04-02 06:46:34 EDT
This request was evaluated by Red Hat Product Management for inclusion
in a Red Hat Enterprise Linux release.  Product Management has
requested further review of this request by Red Hat Engineering, for
potential inclusion in a Red Hat Enterprise Linux release for currently
deployed products.  This request is not yet committed for inclusion in
a release.
Comment 9 Corey Marthaler 2012-09-06 15:59:42 EDT
Verified the new "ALLOCATION" section in the lvm man page.

       When an operation needs to allocate Physical Extents for one or more Logical Volumes, the tools proceed as follows:


lvm2-2.02.88-10.el5    BUILT: Tue Aug 28 01:21:59 CDT 2012
Comment 11 errata-xmlrpc 2013-01-08 02:11:42 EST
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.


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