11-15-2002
With physical partitions, a disk is subdivided into partitions. And somehow the disk driver knows about the subdivision scheme. The driver may read a table off the first sector of the disk. Or the driver may just get the model number of the drive and pick a built-in table. The special files are named to indicate the section. c0t0d0s2 would be section "2" of the disk (which was always the whole thing).
With logical volumes, a disk like c0t0d0s2 (or maybe just c0t0d0 theses days) is just a physical volume which gets tossed into a pool called a volume group. Then you have very great flexibility in creating logical volumes. A logical volume may be a very small slice of a disk. Or it may be so large that it is several disk drives.
10 More Discussions You Might Find Interesting
1. UNIX for Dummies Questions & Answers
Hi Everyone,
Can someone tell me the effect of the pp size of the volume group created for Oracle data.
It would seem that creating small pp's will cause more overhead. What if you make the pp to large? What should I base this size on?
Thanks, (4 Replies)
Discussion started by: kburrows
4 Replies
2. AIX
hello
I have a volume group of 737 Go (EMC)
To add 250 Go, i split the 250 Go to 2*125
No problem to add in the volum group, but when i want to increase the size of the logical volume, i have the message :
0516-787 extendlv: Maximum allocation for logical volume simdatabaselv
is... (3 Replies)
Discussion started by: pascalbout
3 Replies
3. UNIX for Dummies Questions & Answers
Dear Members,
I am using SCO-Unix 5.0.5. I have created 2 logical drives but some of the blocks are overlapped and are now giving warning during startup. I have used fsck to settle the problems but to no avail. Kindly help me to sort out the problem.
Thanks (3 Replies)
Discussion started by: nagendrajaiswal
3 Replies
4. UNIX for Dummies Questions & Answers
I've created a partition with GNU Parted, how do I mount the partition?
The manual information at http://www.gnu.org/software/parted/manual/parted.html is good, but I am sure about how I mount the partition afterwards.
Thanks,
--Todd (1 Reply)
Discussion started by: jtp51
1 Replies
5. AIX
I would like to know how to identify which file a logical partition relates too.
Operating System = AIX
oslevel -s = 5300-04-CSP
I've identified a logical volume that continually runs at 100% tm_acct from iostat.
I've run lvmstat -l and identified the logical partition 590, being the... (1 Reply)
Discussion started by: garry
1 Replies
6. Solaris
Hi All,
I have managed to install and configure a Solaris x86 server, the problem I have now is that whilst setting it up, I left a 30GB logical partition for the Oracle database server that I will later have on the system, the problem now is that I have not formatted the drive during... (18 Replies)
Discussion started by: platforminc
18 Replies
7. AIX
Hi all,
I am trying to replace an old 9gb hard disk for a 36gb hard drive on an AIX 4.3.2 system (can't update)
I was thinking of doing this by doing a dd from the 9gb to the 36gb hard drive and then resize the Logical Volumes. However, lspv <36gb hard disk> gives me the folowing:
#lrnt>... (4 Replies)
Discussion started by: eRJe
4 Replies
8. UNIX for Dummies Questions & Answers
Hi,
I am new to unix. I am working on Red Hat Linux and side by side on AIX also. After reading the concepts of Storage, I am now really confused regarding the terminologies
1)Physical Volume
2)Volume Group
3)Logical Volume
4)Physical Partition
Please help me to understand these concepts. (6 Replies)
Discussion started by: kashifsd17
6 Replies
9. Solaris
hi all
while formatting hard disk i am getting following error.
Partition 1 ends at 266338338
It must be between 34 and 143374704.
label error: EFI Labels do not support overlapping partitions
Partition 8 overlaps partition 1.
Warning: error writing EFI.
Label failed.
I have formatted the... (2 Replies)
Discussion started by: nikhil kasar
2 Replies
10. Red Hat
Hello All,
I have a Red Hat Linux 5.9 Server installed with one hard disk & 2 Partitions created on it as follows,
/boot - Linux Partition & another is
LVM - One VG & under that 5-6 Logical volumes(var,opt,home etc).
Here my requirement is to take out 1GB of space from LVM ( Any logical... (5 Replies)
Discussion started by: gr8_usk
5 Replies
vgchgid(1M) vgchgid(1M)
NAME
vgchgid - modify the Volume Group ID (VGID) on a given set of physical devices
SYNOPSIS
PhysicalVolumePath [PhysicalVolumePath] ...
DESCRIPTION
The command is designed to change the LVM Volume Group ID (VGID) on a supplied set of disks. will work with any type of storage, but it is
primarily targeted at disk arrays that are able to create "snapshots" or "clones" of mirrored LUNs. accepts a set of raw physical devices
and ensures that they all belong to the same volume group, before altering the VGID (see section).
The same VGID is set on all the disks and it should be noted that in cases of multi-PV volume groups, all the physical volumes should be
supplied in a single invocation of the command.
Options
recognizes the following options and arguments:
PhysicalVolumePath The raw devices path name of a physical volume.
Background
Some storage subsystems have a feature which allows a user to split off a set of mirror copies of physical storage (termed or just as LVM
splits off logical volumes with the command. As the result of the "split," the split-off devices will have the same VGID as the original
disks. is needed to modify the VGID on the BCV devices. Once the VGID has been altered, the BCV disks can be imported into a new volume
group by using
WARNINGS
Once the VGID has been changed, the original VGID is lost until a disk device is re-mirrored with the original devices. If is used on a
subset of disk devices (for example, two out of four disk devices), the two groups of disk devices would not be able to be imported into
the same volume group since they have different VGIDs on them. The solution is to re-mirror all four of the disk devices and re-run on all
four BCV devices at the same time, and then use to import them into the same new volume group.
If a disk is newly added to an existing volume group and no subsequent LVM operations has been performed to alter the structures (in other
words, operations which perform an automated vgcfgbackup(1M)); then it is possible a subsequent will fail. It will report that the disk
does not belong to the volume group. This may be overcome by performing a structure changing operation on the volume group (for example,
using
It is the system administrator's responsibility to make sure that the devices provided in the command line are all Business Copy volumes of
the existing standard physical volumes and are in the ready state and writable. Mixing the standard and BC volumes in the same volume
group can cause data corruption.
RETURN VALUE
returns the following values:
0 VGID was modified with no error
1 VGID was not modified
EXAMPLES
An example showing how might be used:
1. The system administrator uses the following commands to create the Business Continuity (BCV or BC) copy:
1) For EMC Symmetrix disks, the commands are and
2) For XP disk array, the commands are and
Three BCV disks are created.
2. Change the VGID on the BCV disks.
3. Make a new volume group using the BCV disks.
This step can be skipped as the group file will be created automatically. If the file is manually created it will have different major
and minor numbers (see lvm(7)).
4. Import the BCV disks into the new volume group.
5. Activate the new volume group.
6. Backup the new volume group's LVM data structure.
7. Mount the associated logical volumes.
SEE ALSO
vgimport(1M), vgscan(1M), vgcfgbackup(1M).
vgchgid(1M)