Logical Volume Management provides storage abstraction, a generalization of disk partitioning.
21
votes
3answers
13k views
Does LVM impact performance?
I have to migrate a few servers to Linux, and one important aspect that I need to evaluate is that my new host system must have elastic storage capacity. Naturally, doing some basic research, I came ...
12
votes
4answers
5k views
SSH to decrypt encrypted LVM during headless server boot?
When I installed Ubuntu 10.04 and, now, 10.10, I was offered the option of enabling "encrypted LVM" for my hard drive.
After choosing that option, I am prompted for my password during boot to decrypt ...
10
votes
1answer
2k views
Using a LVM partition as a Virtualbox drive
Is it possible to use a LVM partition as a Virtualbox disk?
I can't find any option to use a device as a Virtualbox disk, only disk images.
9
votes
4answers
1k views
The merits of a partitionless filesystem
I ran into something a couple of weeks ago that I'd never seen before: A filesystem (ext3 I believe) installed to a storage device without a partition. In essence /dev/sdb was the entire filesystem. I ...
9
votes
2answers
745 views
Choosing filesystem for a 16TB Raid
I'm just putting together a machine with eight 2TB disks.
I will be using Raid 6 (12TB of usable capacity) on top of them, but I'm not sure whether I should make LVM on top of the RAID, or what ...
8
votes
1answer
2k views
How to create a read-only snapshot in LVM, and then rollback to it after some work?
What are the commands to use in LVM in case I want to:
create a read-only snapshot of a volume;
(do some experiments in the volume);
and then rollback the volume to the snapshot?
8
votes
1answer
1k views
Leaking file descriptors
What does it mean if file descriptor leaking
File descriptor 6 (socket:[901758]) leaked on lvextend invocation. Parent PID 10035: /bin/zsh
File descriptor 9 (/dev/pts/1) leaked on lvextend ...
6
votes
3answers
570 views
Any reason for encrypted /?
I am a big fan of linux and like trying out new distros now and then. I usually have my home folders and roots in a lvm atop an encrypted partition, but this tends to become cumbersome with every ...
6
votes
5answers
4k views
Is it possible to put root in LVM without using initrd?
I have just set up a Gentoo base system (which means I can boot and log in and do stuff with it now). My root partition is in an LVM2 virtual group (with a separated /boot partition). In order to boot ...
6
votes
1answer
931 views
How to set keyboard layout used to enter password on an encrypted filesystem?
After my upgrade to Debian 6 (Squeeze), the keyboard layout used to enter the password of encrypted filesystem has been changed. How can I revert it back to previous one?
My understanding is that, ...
6
votes
1answer
4k views
How to configure a filesystem+LVM for effective usage of SSD?
ext4 is one of the filesystems recommended for using on SSDs (with a number of built-in techniques and advices how to tune it for better performance and wear-levelling of SSDs).
I want to install a ...
6
votes
1answer
382 views
Linux device-mapper & ext4: what happens when the COW table fills up?
Consider the following scenario:
I use Linux device mapper to create a snapshot of an ext4 file system.
The snapshot is mounted as read-only; the source volume is mounted as read-write.
I read the ...
5
votes
5answers
687 views
Consumer Level software RAID5 and LVM
Hi I am going to build a 6 drive consumer level RAID 5 (10TB) with Ubuntu10.10 and using EXT4 as filesystem, and OS on another drive.
Question: Should you use LVM on top of the RAID5 or should just ...
5
votes
2answers
7k views
lvm devices under /dev/mapper missing
I'm using Debian squeeze, and running LVM on top of software RAID 1.
I just accidentally just discovered that most of the links under /dev/mapper are missing,
though my system seems to be still ...
5
votes
2answers
267 views
Choosing the file system to use with LVM
Since I found out about LVM I have been giving more thought to the process for choosing the file system for my future installs.
Usually I'd always choose whatever default option the distro would ...
5
votes
3answers
237 views
merging LVM volume groups
Situation:
I have a server with 4 1TB drives in LVM as shown below. The server is a openvz hardware node with a dozen or so openvz containers. At this time each container uses one disk only. This ...
5
votes
1answer
445 views
Can LVM snapshots be writable? (and used for temporary experiments)
It seems that usually it is talked about snapshots as read-only. (In a scenario where one creates a snapshot, then does some experiments with the main volume, and then restores the old state by ...
5
votes
1answer
773 views
Defragmentation of LVM2 logical volumes
Question: Is there a tool supporting de-fragmentation of LVM2 logical volumes ? (Making their extents into consistent sequences)
Preferably by defining desired order of extents (something like ...
5
votes
1answer
1k views
Logical volume missing after reboot
Centos- 6, LVM2
after a system hang and hard reboot.
lvdisplay and lvscan return no volumes. It had volumes earlier...how to recover?
there is data on LV (logical volume) - shared as NFS export..
...
5
votes
2answers
714 views
/dev/md127 refuses to stop. No open files
So I'm trying to stop /dev/md127 on my Ubuntu 12.10 box. It was set up as RAID1, but I'm trying to move everything (well, rename) to md0. I read that renaming isn't possible, so I'm trying to remove ...
5
votes
1answer
1k views
LVM + LUKS + SSD + Gentoo — making it all work together
I'm finding a lot of conflicting information out there, and as of yet haven't found anyone trying to pull together all of the components that I'm trying to do, so I'm hoping someone who understands ...
5
votes
1answer
66 views
Why do some of my lvm partitions have “-real” appended to their names?
In the /dev/mapper directory I can see my lvm partitions, but then I'll see some other ones with the same names, but with "-real" appended to them.
What's that about?
5
votes
3answers
566 views
How to resize an LVM partition at the beginning
I have resized lvm partitions in the past, but after the resize there is space at the end of the partition. What I want to achive is to have the space at the beginning of the partition instead.
The ...
4
votes
4answers
2k views
Any good LVM tutorial?
I'm planning to user LVM in my next linux installation, any links to good LVM tutorials/guides/FAQs would be welcomed.
Thanks in advance.
4
votes
3answers
101 views
What is the best practice for adding disks in LVM
According to the Linux manpages you can add raw disks as well as partitions to a volume group.
In other documentation (RedHat, CentOS or openSUSE), all examples refer to adding partitions to the VG ...
4
votes
6answers
3k views
Should LVM partitions be used in virtual machine images?
Should LVM be used for the partitions when creating VM images (e.g., KVM images)? It seems like it adds complexity if you want to, say, mount a qcow2 image in the host if the image has LVM partitions. ...
4
votes
1answer
81 views
Determining LVM Extent numbers for given file
I'm currently engaged in a non-work related homework exercise. I have an ext4 filesystem sitting on a logical volume. I'm testing different performance tuning strategies and this idea occurred to me. ...
4
votes
2answers
1k views
Mapping between logical and physical block device names
I cannot figure out the mapping between different logical and physical block device names.
The output of "cat /proc/diskstats" is :
104 0 cciss/c0d0 ...
104 1 cciss/c0d0p1 ...
104 2 ...
4
votes
4answers
1k views
Partitioning a 2tb drive
Im new to linux
Im planning to install Squeeze on a 2tb hard drive a follows:
/ - 10gb
swap
remaining space will contain /home, around 1.9tb i hope, i will try
to use as lvm to add my old 1tb drive ...
4
votes
1answer
961 views
Does LVM increase the risk of data loss?
Let's say I have two identical disks, and I set one LVM logical volume on them (no mirroring). Question: What will happen when one of the disks fails?
I will lose all the data from all the disks
I ...
4
votes
2answers
737 views
RHEL6 LUKS with TPM support?
I'm surprised that this question is not asked more frequently, but (in RHEL) does LUKS support TPM's the way that Windows BitLocker does? If so, how is this feature implemented, and does it provide ...
4
votes
1answer
565 views
How can I resize my root partition in Debian?
I am trying to add space to my root partition and am really not sure the safest way to go about it. I have read this thread, Can I resize the root partition without uninstalling and reinstalling ...
4
votes
1answer
228 views
Alternatives to LVM
I was thinking about alternatives to combine several HDDs together.
The only options I know so far are using LVM and/or RAID.
The thing is, using LVM, I will most probably lose all data, if one ...
4
votes
4answers
833 views
Recovering overwritten LVM metadata
Yesterday I was trying using the Debian install in rescue mode in order to fix my Grub (The menu-item for Debian was suddenly gone).
Now I wasn't able to fix it and didn't have a lot of time, so I ...
4
votes
1answer
269 views
What filesystem has best support for shrinking?
Most mainstream filesystems can be grown fairly reliably, but what if I think I would like to shrink in future?
XFS is a non runner. Reiser seems to have good support but gives scary BETA warnings , ...
4
votes
1answer
245 views
Resizing logical volume with no free extents but with free disk space
I have a 7.9 TB logical volume formatted with XFS filesystem. I have 8 1 TB RAID devices as physical volumes, and 1 volume group that contains all of these devices. I have 2.5 TB free space on my ...
4
votes
1answer
1k views
LVM Mirrored Logical Volume Performance
I read that when mirroring a logical volume a log of some sort is used to keep the files in sync. You can either set it so this log is in a separate physical volume or in memory. I also read that if ...
4
votes
1answer
81 views
Do LVM snapshots ultimately cause fragmentation?
I'm planning on using LVM in order to be able to take atomic snapshots of large files and rsync them to a remote site.
What I'd like to know is whether there is any long-term impact on the main ...
4
votes
1answer
173 views
Why does activation of LVM partition with large snapshot takes long time?
After creating large snapshot (I assume it drifted about 30GB from the original) I noticed that vgchange -ay took noticeable longer (to the point I thought computer hanged).
What does the activation ...
4
votes
1answer
373 views
NFS server causes high load even when idle
I have an Ubuntu (12.04) NFS server that has a high load (larger than 10) even when nothing is running.
In detail, the storage is provided by an iSCSI device, on which I have 5 logical volumes (LVM) ...
3
votes
1answer
37 views
Not able to extend the size of an LVM logical volume
During RedHat installation, I created one volume group with two logical volumes in it.
Volume Group Name = VolGroup00
LVMs = LogVol00 and LogVol01
LogVol00 size = 48G
LogVol01 size = ...
3
votes
3answers
450 views
Copying an HDD to a larger one by dd
I'm trying to copy an entire HDD which has IBM PC-style partition table to a larger one by dd on GNU/Linux. The questions are:
Can I use the additional space on the larger disk by changing the ...
3
votes
3answers
899 views
Temporary restore LVM snapshot of root
I have a snapshot of the root filesystem that I want to boot with - bring the machine into a state it was a few days ago, run some tests and then go back to where I am right now.
I tried editing ...
3
votes
4answers
3k views
Partition manager that can handle LVM?
I have been looking but neither Gparted nor KDE Partition Manager can handle LVM. Working with the command line is probably fine but it would be clearer to have a GUI tool here. Does such thing exist?
...
3
votes
1answer
763 views
Why is there a mismatch between size reported by LVM and the size reported by df -h?
I'm new to LVM and have been very confused by this:
I am transfering a large file to a partition that I thought had about 1.5 terabytes of space on it. Near the end of the transfer, rsync exits with ...
3
votes
2answers
160 views
Can lvm2 volumes based on device names like sda, sdb etc be mounted if their names change?
Lets say I would like to make a large volume from external usb drives. I create the lvm volume on drives that have been given certain device names sdf sdg or whatever and at some point they are ...
3
votes
1answer
78 views
What's the easiest way to decrypt a disk partition?
I made a mistake of encrypting the entire LVM physical volume (contains both home, root, and swap) when installing a CentOS 6.4 (2.6.32-358.6.1.el6.x86_64) box. I soon came to realize that moving ...
3
votes
1answer
426 views
dual booting centos5.5 and fedora
I already have centos5.5 on my system whose hard disk is ~500GB. I have tried to dual boot with fedora 16. while installing fedora 16 I have created a ~250GB and ~4GB partitions for "/" and swap. The ...
3
votes
2answers
145 views
Is there any performance penalty to having multiple segments for one volume in LVM?
We have a big drive that we've split up using LVM. We allocated one segment to the root filesystem and several other segments to other filesystems. Then we wanted to add more space to the root ...
3
votes
1answer
6k views
gparted live CD can't resize a partition?
I recently ran out of space on a VirtualBox VM (CentOS guest) managed by Vagrant. It was using a .vmdk image, so I couldn't dynamically resize it. Following these instructions, I cloned the old image ...
