Questions tagged [lvm]
In computer storage, Logical Volume Management or LVM provides a method of allocating space on mass-storage devices that is more flexible than conventional partitioning schemes.
112
questions
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LVM dangers and caveats
I have recently started using LVM on some servers for hard drives larger than 1 TB. They're useful, expandable and quite easy to install. However, I could not find any data about the dangers and ...
20
votes
4answers
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Is this how LVM snapshots work?
I'm trying to figure out how LVM snapshots work so I can implement it on my fileserver but I'm having difficulty finding anything on google that explains how it works, instead of how to use it for a ...
10
votes
8answers
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Ubuntu: Resize the root LVM(2?) partition
I have an Ubuntu virtual machine running in VirtualBox 2.2.4, and I created it on an 8gb virtual disk which is too small.
So, I am trying to increase the size of the disk. So far, I have done this:
...
6
votes
6answers
14k views
Is there a way to do something like LVM over NFS?
I realize that since NFS is not block-level, LVM can't be used directly.
However: is there a way to combine multiple NFS exports (from, say, 3 servers) into one mount point on a different server?
...
29
votes
3answers
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Readahead Settings for LVM, Device-Mapper, Software Raid and Block Devices - what wins?
I've been trying to find a straight answer on this one, and it has proved elusive. This question and its answer is close, but does not really give me the specifics I would like. Let's start with ...
9
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5answers
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LVM mirroring VS RAID1
Having learned a bit about LVM mirroring, I thought about replacing the current RAID-1 scheme I'm using to gain some flexibility.
Problem is that according to what I found on the Internet, LVM is:
...
23
votes
11answers
36k views
Sync LVM snapshots to backup server
I have a number of Xen virtual machines running on a number of Linux servers. These VMs store their disk images in Linux LVM volumes with device names along the lines of /dev/xenVG/SERVER001OS and so ...
17
votes
9answers
29k views
LVM snapshots as a backup strategy
How viable as a backup strategy would be periodical LVM snapshots of xen domU's? Pros, cons, any gotchas?
To me it seems like the perfect solution for a fast, brainless restore. Any investigation ...
27
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7answers
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How to resize root LVM partition in Fedora without LiveCD or Rebooting
I have a virtual machine that recently had its disk image increased from 20GB to 50GB, and fdisk -l verifies that the VM can see this new size. Now I need to resize my root LVM partition to fill the ...
20
votes
6answers
14k views
Possible to get SSD TRIM (discard) working on ext4 + LVM + software RAID in Linux?
We use RAID1+0 with md on Linux (currently 2.6.37) to create an md device, then use LVM to provide volume management on top of the device, and then use ext4 as our filesystem on the LVM volume groups.
...
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4answers
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LVM logical volume partition corrupted after lvreduce
I encounter the problem when I try to shrink one logical volume. I took the actions as following steps shows:
# unmount /home
# lvreduce --size -100G /dev/vg_dev/lv_home
# lvdisplay /dev/vg_dev/...
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3answers
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Centos Xen resizing DomU partition and volume group
I have a setup like so:
Dom0 LV
|
DomU Physical Disk
| |
XVDA1 XVDA2
(/boot) (DomU PV)
|
VolGroup00
(DomU VG)
...
6
votes
2answers
6k views
Is it possible to convert striped logical volume to linear logical volume?
I've a logical volume that is striped across three physical volumes. I had to move this logical volume to another physical volume. This worked nicely with pvmove command. However, I discovered later ...
23
votes
6answers
28k views
Does LVM need a partition table?
It appears that I am able to successfully do a pvcreate on top of a raw block device, without ever taking the step of creating a partition table. I am then able to create a volume group, logical ...
12
votes
5answers
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How to recover logical volume deleted with lvremove
I am on CentOS 5.5 and am running Xen. I have a large volume group that I create logical volumes on using lvcreate. Today I had a customer cancel her account, then change her mind about an hour ...
16
votes
7answers
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How to extend a Linux PV partition online after virtual disk growth
VMware allows to extend the size of a virtual disk online - when the VM is running.
The next expected steps for Linux system are:
extend the partition: delete and create a larger one with fdisk
...
17
votes
6answers
25k views
Commit or revert a Linux LVM snapshot?
I'm about to perform an experimental upgrade on my CentOS 5 server. If the upgrade fails, I want to be able to back out the changes to the filesystem. This scenario seems similar to the example in ...
19
votes
7answers
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Is it possible to convert a Linux box to LVM after the fact?
My Linux server uses LVM because I replace the machine a year ago and installed from scratch. LVM has been a life saver and I love its flexibility. My Linux laptop, however, was last fully installed ...
10
votes
9answers
60k views
Logical volumes are inactive at boot time
I resized my logical volume and filesystem and all went smoothly. I installed new kernel and after reboot I can't boot neither current nor former one. I get volume group not found error after ...
17
votes
7answers
22k views
Do you lose everything when you have a hard disk failure in a multi-hard disk LVM that does NOT use RAID?
I'm debating about using LVM for a media/file server because I would like to combine multiple physical hard disks into one volume. I do not wish to use any RAID in my LVM so my question is:
If one ...
28
votes
5answers
25k views
LVM Performance overhead?
I would be thankfull if someone who understands how LVM works, could tell me a rough estimate, how much slower using LVM (with a Software RAID1) will be.
(What I do not want to know how much slower ...
14
votes
3answers
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Linux device-mapper maps LVM PV nested inside LV when taking snapshot
Which is really messing with my plan to back up this machine...
I have a server which is a KVM hypervisor to several virtual machines. One of these is running Docker. It has its Docker volumes on /...
14
votes
4answers
7k views
Improving IO with FlashCache
I have a server with 2 HDD's (2x 1 TB), running in RAID 1 (SW-RAID). I want to improve IO performance by using flashcache. There are running KVM virtual machines on it, using LVM.
Regarding this, I ...
6
votes
1answer
9k views
Advantages and disadvantages of Logical Volume Manager (LVM)? And LVM vs encrypted LVM?
In my situation, it's for a local build/staging server running ubuntu server. Things I'd like to know are:
Why I should/shouldn't use LVM?
What problems might it cause in terms of either regular ...
5
votes
2answers
5k views
Ubuntu Kickstart installation using LVM waits for input
I have a PXE Boot Setup for installing CentOS 5 and Ubuntu 10.04 via Kickstart. I use LVM and installing CentOS without any user interaction works but Ubuntu always asks to "confirm to write changes ...
2
votes
1answer
1k views
Recovering Accidentally Destroyed LVM2 Information
Ok, so I'm stupid and made a serious and grave mistake. On my linux box running Ubuntu 10.10, I have a 1.5TB RAID array that I had originally setup using the instructions located here: http://www....
7
votes
2answers
7k views
Insufficient suitable allocatable extents when extending lvm
I have a volume-group (vg) with about 127GB free space. I am trying to extend a logical volume to +50GB however i am getting
insufficient suitable allocatable extents
This is quite weird since ...
3
votes
1answer
2k views
pvcreate not working: can't open exclusively
After having added 2 disks of 1Tb to a Dell PowerEdge, I went through their initialization with the goal to add them to an existing LVM VG.
When the MegaCli background initialization went complete, I ...
1
vote
3answers
27k views
How to change Volumegroup PE size
I am trying to increase the PE size of one of my Volume groups.
I mistakenly set it as 4M to start when it should have been 32M .
When I try to change the size I get
vgchange -s 32M the_vol
New ...
5
votes
3answers
5k views
Which scheduler to change on LVM to benefit virtual machines
When you have LVM, you have an entry for a scheduler in /sys/block for your physical volumes, but also for each individual logical volume, and the raw device.
We have a Debian 6 LTS x64, kernel 2.6....
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votes
3answers
4k views
Increase Linux Partition dynamically?
Here is what I have on my Linux Box
[root@linxuph53 logs]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vg_linuxph53-lv_root
38G 11G 26G 29% /
...
0
votes
2answers
460 views
Kill a process inside an lvm snapshot
In my XEN host, I have a snapshot that cannot be removed with lvremove
$ lvremove /dev/vg0/snap-tmp-vm06.docker-disk -fdv
DEGRADED MODE. Incomplete RAID LVs will be processed.
Using logical volume(s) ...
23
votes
4answers
34k views
KVM/qemu - use LVM volumes directly without image file?
I'm not quite sure how to phrase this question (hence the poor title), so let me provide an example of what I'm trying to do.
On my (old) Xen host, I'm able to present LVM filesystems directly to ...
47
votes
6answers
53k views
What is better LVM on RAID or RAID on LVM?
I currently have LVM on software RAID, but I'd like to ask you what you think it is better solution, maybe some pros and cons?
Edit: It is about software raid on lvm or lvm on software raid. I know ...
22
votes
6answers
25k views
How do I easily repair a single unreadable block on a Linux disk?
My Linux system has started throwing SMART errors in the syslog. I tracked it down and believe the problem is a single block on the disk. How do I go about easily getting the disk to reallocate that ...
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votes
3answers
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Is it possible to on-line shrink a EXT4 volume with LVM?
Today I tried this on my machine with OpenSUSE 12.3 (kernel 3.7):
# resize2fs /dev/mapper/system-srv 2G
resize2fs 1.42.6 (21-Sep-2012)
Filesystem at /dev/mapper/system-srv is mounted on /srv; on-line ...
28
votes
1answer
6k views
When using software RAID and LVM on Linux, which IO scheduler and readahead settings are honored?
In the case of multiple layers (physical drives -> md -> dm -> lvm), how do the schedulers, readahead settings, and other disk settings interact?
Imagine you have several disks (/dev/sda - /dev/sdd) ...
33
votes
4answers
14k views
LVM snapshots vs. file system snapshots
As far as I know, LVM makes it possible to take snapshots of a volume. There are also a number of file systems (ZFS, Btrfs, reiserfs, ...) which supports snapshots.
However, I've never understood the ...
15
votes
1answer
13k views
Resizing a LUKS encrypted volume
I have a 500GiB ext4 filesystem on top of LUKS on top of an LVM LV. I want to resize the LV to 100GiB. I know how to resize ext4 on top of an LVM LV, but how do I deal with the LUKS volume?
mgorven@...
12
votes
3answers
8k views
LVM volume group shared between KVM/libvirt host and guests: is this a bad idea?
I have just built a shiny new KVM/libvirt-based virtual machine host, containing 4 SATA II hard drives, and running CentOS 5.5 x86_64.
I have decided to create virtual machine disks as logical ...
15
votes
5answers
25k views
Is online disk resize possible with KVM?
We're evaluting KVM for Linux virtualization on a few projects. All is going well so far. But one of our requirements is the ability to add disk space to a running guest without rebooting or taking it ...
13
votes
5answers
11k views
LVM and disaster recovery
I understand what LVM is and what it accomplishes, but I feel like I am missing some things.
Lets say we have two physical drives, sda and sdb. Both are 100 Megs. I put them into VolumeGroup1 and ...
10
votes
5answers
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Best practices for thin-provisioning Linux servers (on VMware)
I have a setup of about 20 Linux machines, each with about 30-150 gigabytes of customer data. Probably the size of data will grow significantly faster on some machines than others. These are virtual ...
8
votes
4answers
5k views
Using 4k drives with md/LVM/dm-crypt
I know that I have to align my 4k drives by a multiple of 8 sectors, but what about md-RAID / LVM / dm-crypt? How do I tell these layers that my drive is 4k? If they don't respect the 4k sector size, ...
8
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2answers
5k views
Is the fdisk partition type important when using lvm
I have inherited a few LVM volumes and I noticed that fdisk reports the disks that make up the volume group as partition type 83 (Linux) and not 8e (Linux LVM). Is this a problem and how important ...
5
votes
3answers
14k views
KVM booting off-image kernel and existing partition
I am in the process of switching from Xen to qemu-kvm. My current Xen installation has a number of LVM volumes each with a partition (rather than a full disk image). In Xen, I start each VM with a ...
8
votes
3answers
14k views
debian 6 preseeding keeps asking “Write the changes to disks and configure LVM?”
I try to use an expert recipe configuring lvm for debian 6.0.5 netinstall. I don't want to be asked any questions, but it keeps asking me "Write the changes to disks and configure LVM?"
Here is part ...
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votes
4answers
6k views
Linux Software RAID1: How to boot after (physically) removing /dev/sda? (LVM, mdadm, Grub2)
A server set up with Debian 6.0/squeeze. During the squeeze installation, I configured the two 500GB SATA disks (/dev/sda and /dev/sdb) as a RAID1 (managed with mdadm). The RAID keeps a 500 GB LVM ...
5
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6answers
4k views
JFS or XFS or anything else?
After deciding to use LVM2 as volumemanager on our servers there was also the wish for an online resizeable filesystem. After reading a few articles I decided to use JFS in favour of XFS.
Now today I ...
4
votes
2answers
7k views
repair partition table
I've just overwritten my partition table of my system's hard disk. i made a cfdisk on the wrong device (/dev/sda instead of /dev/sdd), deleted all partitions, made one new primary spanning over the ...
