Talk:Logical volume management

LE and other acronyms like PE, PV, and VG
What is an LE? All these acromyms should be explained, or better yet, in an encyclopedia, expanded to thier full form: LV, PE, PV, PVG. The shortened version is easy on the writer, harder on the reader. —Preceding unsigned comment added by Gbeeker (talk • contribs)


 * I disagree they should be expanded. It would be confusing when using any lvm management tools. A reference section yes, but expanding these in all cases is going to cause confusion to anyone reading and then using lvm utilities. —Preceding unsigned comment added by 199.84.5.210 (talk • contribs)


 * Also, what is the relationship between Volume Groups (VGs) and Logical Volumes (LVs). —Preceding unsigned comment added by 217.158.168.198 (talk • contribs)


 * The HOWTO link should be able to explain this in more detail now. What about migrating more info. from the HOWTO into this page? Sasank 04:09, 16 May 2006 (UTC) Is the HOWTO link too linux specific? But I think its worth having it. Sasank 04:11, 16 May 2006 (UTC)

logical extent (LE): Each logical volume is split into chunks of data, known as logical extents. The extent size is the same for all logical volumes in the volume group. —Preceding unsigned comment added by 71.106.3.140 (talk • contribs)


 * I just moved the Terminology section to the top and expanded it. --Unixguy 13:24, 26 June 2007 (UTC)


 * As of now, the article is very tiring to read with the use of many similar abbreviations. I'd highly suggest expanding the acronyms; if there's need for a short outline using the acronyms, it should be an additional section, not the main description body. From a user perspective, there seems to be little use in using the abbreviations as they map clearly from their long name to the acronym (especially for people actually working with the system, i.e. being familiar with the acronyms); in contrast, for an inexperienced person trying to understand the concept, the acronyms are quite confusing due to being very similar. Golan2781 (talk) 09:45, 27 June 2012 (UTC)

Historical notes
Part 1: I don't know why other entities developed their LVMs but as one of the co-inventors of IBM's, I do know our motivations. One of the biggest was that disk drives of the era (1986) typically were in the 40 MByte range, yet our customers wanted to operate on very large files. Boeing, in particular, needed to operate on CATIA / CADAM files that were in the GByte range, including some that were large than 2^31. Our LVM was first conceptualized to address Boeing's needs.

Part 2: The article should be corrected on some points I think. For example, the first version of AIX for the RISC System/6000, which our LVM, was 3.1, not 3.0. The article is correct that the LVM dates to 1989, although AIXv3.1 and the RISC System/6000 were not generally available until 1Q 1990. Perhaps a historical note might be added that the LVM idea, at least for UNIX systems, was first conceptualized in 1986. A U.S. patent application for it was first filed in Nov. 1987 (US 5,129,088) establishing the terminology that still is used today: logical volume manager, volume group, logical volume, physical volume, logical partition, physical partition, and so forth.

Part 3: IBM wisely chose not to enforce the patent, preferring to focus on unifying the forces of light vs. the forces of darkness. 8-) [In those days, AT&T and Sun had formed an alliance that the other UNIX vendors believed would deprive them of fair access to UNIX. They worried that AT&T was planning to use Sun to enter the computer business and that Sun was planning to use AT&T to starve the other UNIX vendors out of existence. One result of the "unholy alliance" was the formation of the "Open Software Foundation," OSF, now known as the Open Group.)

Part 4: I know whereof I speak: I was the AIX engineer responsible for the architecture and design of the LVM. Moreover, I wrote most of the patent application, drew most of the drawings, and so forth. Yet further, I helped get the OSF going. Stephen P Morgan (talk)Stephen P. MorganStephen P Morgan (talk), stephen_p_morgan@sbcglobal.net. Nov 1st, 2008. User:Stephen P Morgan

Feature differences
I think it would be neccessary to point out features like mirror policies (PVG-strict mirroring or whatever the volume manager calls it), as most people are unaware how deeply linux LVM lacks in these areas. it is not a point of flaming it, but people need to be aware to be able to plan their setups more wisely. also snapshots or ability to resync single PE / Plexes are areas with major differences between all the different volume managers.

lastly, EVMS is SO dead. —Preceding unsigned comment added by 82.135.62.109 (talk) 17:58, 14 September 2010 (UTC)

GEOM
The FreeBSD volume management framework is also worth an entry, maybe someone knows enough about it? —Preceding unsigned comment added by 82.135.62.109 (talk) 18:01, 14 September 2010 (UTC)

Core Storage Evolution
With Moutain Lion, Core storage has gain new uses : It for instance enable Fusion Drive. — Preceding unsigned comment added by 92.158.74.90 (talk) 16:28, 1 May 2013 (UTC)

Volume group merger proposal
Currently, Volume group article is a very short stub, and as such is should be merged into section. This section already contains a much better explanation of logical volumes, together with providing a much broader context. Thoughts? &mdash; Dsimic (talk | contribs) 07:33, 27 September 2014 (UTC)


 * The "Logical Volume Management" article covers a larger array of volume management than just Linux LVM. There's already an article about Linux LVM that seems to contain most of this information. I would recommend just setting up a redirect from this page to the Linux LVM page since I don't think VG's have enough to them to warrant an entire page on their own. A section maybe, but you'd be hard press to fill an entire page. 152.16.191.70 (talk) 21:34, 20 May 2015 (UTC)


 * Thanks for your input, let's see if anyone else wants to weigh in. &mdash; Dsimic (talk | contribs) 07:43, 21 May 2015 (UTC)


 * Given how long it was between when this was initially proposed and now (approx. 5 months) I don't think there's going to be much input. Given how little is in the mentioned article, would there be an issue to just going ahead and doing it now? 152.16.191.70 (talk) 14:17, 21 May 2015 (UTC)


 * There should be no issues, but please perform all steps described in WP:PROMERGE. &mdash; Dsimic (talk | contribs) 20:54, 21 May 2015 (UTC)