pvmove(8)
NAME
pvmove --- move physical extents
SYNOPSIS
pvmove [--abort] [--alloc AllocationPolicy] [--atomic]
[-b|--background] [--commandprofile ProfileName] [-d|--debug]
[-h|--help] [-i|--interval Seconds] [--noudevsync] [--reportformat
{basic|json}] [-v|--verbose] [-n|--name LogicalVolume]
[SourcePhysicalVolume[:PE[-PE]...]
[DestinationPhysicalVolume[:PE[-PE]...]...]]
DESCRIPTION
pvmove allows you to move the allocated physical extents (PEs) on SourcePhysicalVolume to one or more other physical volumes (PVs). You can optionally specify a source LogicalVolume in which case only extents used by that LV will be moved to free (or specified) extents on DestinationPhysicalVolume(s). If no DestinationPhysicalVolume is specified, the normal allocation rules for the Volume Group are used. If pvmove gets interrupted for any reason (e.g. the machine crashes) then run pvmove again without any PhysicalVolume arguments to restart any moves that were in progress from the last checkpoint. Alternatively use pvmove --abort at any time to abort. The resulting location of logical volumes after an abort is issued depends on whether the --atomic option was used when starting the pvmove process. You can run more than one pvmove at once provided they are moving data off different SourcePhysicalVolumes, but additional pvmoves will ignore any Logical Volumes already in the process of being changed, so some data might not get moved. pvmove works as follows: 1. A temporary 'pvmove' Logical Volume is created to store details of all the data movements required. 2. Every Logical Volume in the Volume Group is searched for contiguous data that need moving according to the command line arguments. For each piece of data found, a new segment is added to the end of the pvmove LV. This segment takes the form of a temporary mirror to copy the data from the original location to a newly-allocated location. The original LV is updated to use the new temporary mirror segment in the pvmove LV instead of accessing the data directly. 3. The Volume Group metadata is updated on disk. 4. The first segment of the pvmove Logical Volume is activated and starts to mirror the first part of the data. Only one segment is mirrored at once as this is usually more efficient. 5. A daemon repeatedly checks progress at the specified time interval. When it detects that the first temporary mirror is in-sync, it breaks that mirror so that only the new location for that data gets used and writes a checkpoint into the Volume Group metadata on disk. Then it activates the mirror for the next segment of the pvmove LV. 6. When there are no more segments left to be mirrored, the temporary Logical Volume is removed and the Volume Group metadata is updated so that the Logical Volumes reflect the new data locations. Note that this new process cannot support the original LVM1 type of on- disk metadata. Metadata can be converted using vgconvert(8). If the --atomic option is used, a slightly different approach is used for the move. Again, a temporary 'pvmove' logical volume is created to store the details of all the data movements required. This temporary LV contains all the segments of the various LVs that need to be moved. However this time, an identical logical volume is allocated that contains the same number of segments and a mirror is created to copy the contents from the first temporary LV to the second. When a complete copy is accomplished, the temporary logical volumes are removed, leaving behind the segments on the destination physical volume. If an abort is issued during the move, all logical volumes being moved will remain on the source physical volume.
OPTIONS
See lvm(8) for common options. --abort Abort any moves in progress. If the --atomic option was used to start the pvmove, all logical volumes will remain on the source physical volume. Otherwise, those segments that have completed the move will stay on the destination physical volume, while those that have not will remain on the source physical volume. --atomic Make the entire operation atomic. That is, ensure that all affected logical volumes are moved to the destination physical volume together; unless the move has been aborted. If the move has been aborted, all logical volumes will remain on the source physical volume. --noudevsync Disable udev synchronisation. The process will not wait for notification from udev. It will continue irrespective of any possible udev processing in the background. You should only use this if udev is not running or has rules that ignore the devices LVM2 creates. -b, --background Run the daemon in the background. -i, --interval Seconds Report progress as a percentage at regular intervals. -n, --name LogicalVolume Move only the extents belonging to LogicalVolume from SourcePhysicalVolume instead of all allocated extents to the destination physical volume(s).
Examples
To move all Physical Extents that are used by simple Logical Volumes on /dev/sdb1 to free Physical Extents elsewhere in the Volume Group use: pvmove /dev/sdb1 Additionally, a specific destination device /dev/sdc1 can be specified like this: pvmove /dev/sdb1 /dev/sdc1 To perform the action only on extents belonging to the single Logical Volume lvol1 do this: pvmove -n lvol1 /dev/sdb1 /dev/sdc1 Rather than moving the contents of the entire device, it is possible to move a range of Physical Extents - for example numbers 1000 to 1999 inclusive on /dev/sdb1 - like this: pvmove /dev/sdb1:1000-1999 A range can also be specified as start+length, so pvmove /dev/sdb1:1000+1000 also refers to 1000 Physical Extents starting from Physical Extent number 1000. (Counting starts from 0, so this refers to the 1001st to the 2000th inclusive.) To move a range of Physical Extents to a specific location (which must have sufficient free extents) use the form: pvmove /dev/sdb1:1000-1999 /dev/sdc1 or pvmove /dev/sdb1:1000-1999 /dev/sdc1:0-999 If the source and destination are on the same disk, the anywhere allocation policy would be needed, like this: pvmove --alloc anywhere /dev/sdb1:1000-1999 /dev/sdb1:0-999 The part of a specific Logical Volume present within in a range of Physical Extents can also be picked out and moved, like this: pvmove -n lvol1 /dev/sdb1:1000-1999 /dev/sdc1
SEE ALSO
lvm(8), vgconvert(8) pvs(8)
Opportunity
Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.
Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.
Free Software
Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.
Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.
Free Books
The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.
Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.
Education
Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.
Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.
