hpr3727 :: Expanding your filesystem with LVM
Rho`n describes adding a new hard drive to his work computer and expanding its filesystem
Hosted by Rho`n on Tuesday, 2022-11-15 is flagged as Clean and is released under a CC-BY-SA license.
LVM, Linux Volume Management, hard drive, SSD.
1.
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general.
Synopis
I installed a new 1TB Crucial MX500 SSD into my work computer. While we are mostly a Windows based business, as the IT guy I do get a bit of discretion when updating my own machine (i.e. I get to solve all the problems I create). Last year, I decided to run the Pop!_OS distribution of Linux on my work computer and run Windows in a VM on it. Recently the Windows image had grown and was causing disk space notifications. This prompted the additional hard drive.
During the initial installation of Pop!_OS, I remember deciding not to bother with installing Linux Volume Management (LVM). I have used it in the past, but I am still much more comfortable with the old style device mapping and mounting disk partitions to directories. I even rationalized that if I needed to add more space, I will just add a new disk with one big partition and map it to the home directory.
Now a year later I am adding a new HD and thinking, I really hate all the space that is most likely going to be wasted once I move the Windows image to the new drive. Ok, I guess I should figure out how to install LVM, and use it to manage the space on both drives. Luckily there a number of good blogs to be found on adding LVM to an existing system. The following are the steps and commands I used to accomplish my goal.
Commands
Most of the following commands need to be run as root. I decided to change to root user instead of typing sudo before every command. The basic steps to creating a single filesystem sharing the storage space between two physical disk partitions are:
- Let LVM know about the new disk.
- In my case, create a volume group and add the new disk and its full storage space to it.
- Copy the disk partition with the root filesystem from the origin disk to the new volume group
- Expand the root filesystem on the volume group to the full size of the volume group.
- Update system configuration to boot with the root filesystem on the new volume group.
- Let LVM know about the old root disk partition.
- Add the old root partition to the volume group.
- Expand the root filesystem on the volume group to include the new space in the volume group.
root@work# pvcreate /dev/sdb
root@work# pvdisplay
"/dev/sdb" is a new physical volume of "931.51 GiB"
--- NEW Physical volume ---
PV Name /dev/sdb
VG Name
PV Size 931.51 GiB
Allocatable NO
PE Size 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID wRBz38-xxxx-xxxx-xxxx-xxxx-xxxx-xxxxxx
root@work# vgcreate workvg /dev/dsb
No device found for /dev/dsb.
root@work# vgcreate workvg /dev/sdb
Volume group "workvg" successfully created
root@work# vgdisplay
--- Volume group ---
VG Name workvg
System ID
Format lvm2
Metadata Areas 1
Metadata Sequence No 1
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 0
Open LV 0
Max PV 0
Cur PV 1
Act PV 1
VG Size 931.51 GiB
PE Size 4.00 MiB
Total PE 238467
Alloc PE / Size 0 / 0
Free PE / Size 238467 / 931.51 GiB
VG UUID 67DSwP-xxxx-xxxx-xxxx-xxxx-xxxx-xxxxxx
root@work# pvdisplay
--- Physical volume ---
PV Name /dev/sdb
VG Name workvg
PV Size 931.51 GiB / not usable 1.71 MiB
Allocatable yes
PE Size 4.00 MiB
Total PE 238467
Free PE 238467
Allocated PE 0
PV UUID wRBz38-xxxx-xxxx-xxxx-xxxx-xxxx-xxxxxx
root@work# lvcreate -n root -L 931.51 workvg
Rounding up size to full physical extent 932.00 MiB
Logical volume "root" created.
root@work# cat /dev/sda3 >/dev/mapper/workvg-root
cat: write error: No space left on deviceHmmm why can't it copy the smaller disk onto a larger one?
root@work# pvdisplay
--- Physical volume ---
PV Name /dev/sdb
VG Name workvg
PV Size 931.51 GiB / not usable 1.71 MiB
Allocatable yes
PE Size 4.00 MiB
Total PE 238467
Free PE 238234
Allocated PE 233
PV UUID wRBz38-xxxx-xxxx-xxxx-xxxx-xxxx-xxxxxx
root@work# lvdisplay
--- Logical volume ---
LV Path /dev/workvg/root
LV Name root
VG Name workvg
LV UUID srXpUd-xxxx-xxxx-xxxx-xxxx-xxxx-xxxxxx
LV Write Access read/write
LV Creation host, time work.example.com, 2022-10-18 08:46:34 -0400
LV Status available
# open 0
LV Size 932.00 MiB
Current LE 233
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:1Whoops, the default unit for the lvcreate is MB, and I forgot to add G to my size. A good reason to always include units in whatever you do :) Also, pay attention to any reports printed at the end of a successful command. When I scrolled back I realized it told me the size it created.
root@work# lvextend -l +100%FREE /dev/workvg/root
Size of logical volume workvg/root changed from 932.00 MiB (233 extents) to 931.51 GiB (238467 extents).
Logical volume workvg/root successfully resized.
root@work# lvdisplay
--- Logical volume ---
LV Path /dev/workvg/root
LV Name root
VG Name workvg
LV UUID srXpUd-xxxx-xxxx-xxxx-xxxx-xxxx-xxxxxx
LV Write Access read/write
LV Creation host, time work.example.com, 2022-10-18 08:46:34 -0400
LV Status available
# open 0
LV Size 931.51 GiB
Current LE 238467
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:1
root@work# cat /dev/sda3 >/dev/mapper/workvg-root
root@work# mkdir /media/new-root
root@work# mount /dev/mapper/workvg-root /media/new-root
root@work# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 450G 421G 5.6G 99% /
/dev/sda1 497M 373M 125M 76% /boot/efi
/dev/sda2 4.0G 3.4G 692M 84% /recovery
/dev/mapper/workvg-root 450G 421G 5.7G 99% /media/new-rootOk, the LV volume is resized but the filesystem now needs to expanded to use the new disk space
root@work# umount /media/new-root/
root@work# resize2fs /dev/mapper/workvg-root
resize2fs 1.46.5 (30-Dec-2021)
Please run 'e2fsck -f /dev/mapper/workvg-root' first.
root@work# e2fsck -f /dev/mapper/workvg-root
e2fsck 1.46.5 (30-Dec-2021)
Pass 1: Checking inodes, blocks, and sizes
Inode 7210086 extent tree (at level 2) could be narrower. Optimize<y>? yes
Pass 1E: Optimizing extent trees
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
/dev/mapper/workvg-root: ***** FILE SYSTEM WAS MODIFIED *****
/dev/mapper/workvg-root: 827287/29974528 files (1.2% non-contiguous), 112395524/119870981 blocks
root@work# resize2fs /dev/mapper/workvg-root
resize2fs 1.46.5 (30-Dec-2021)
Resizing the filesystem on /dev/mapper/workvg-root to 244190208 (4k) blocks.
The filesystem on /dev/mapper/workvg-root is now 244190208 (4k) blocks long.
root@work# mount /dev/mapper/workvg-root /media/new-root
root@work# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 450G 421G 5.5G 99% /
/dev/mapper/workvg-root 916G 421G 449G 49% /media/new-rootMuch better. Now we need to get the computer to boot using LVM and
the new drive. Need to make sure /etc/fstab is updated to
point to the new root filesystem.
Make some in-memory filesystems available under the new root:
root@work# mount --rbind /dev /media/new-root/dev
root@work# mount --bind /proc /media/new-root/proc
root@work# mount --bind /sys /media/new-root/sys
root@work# mount --bind /run /media/new-root/run
root@work# chroot /media/new-root
root@work# cat /etc/fstab
# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point> <type> <options> <dump> <pass>
PARTUUID=949a09f0-xxxx-xxxx-xxxx-xxxxxxxxxxxx /boot/efi vfat umask=0077 0 0
PARTUUID=bbcc2068-xxxx-xxxx-xxxx-xxxxxxxxxxxx /recovery vfat umask=0077 0 0
UUID=9f1f68bb-xxxx-xxxx-xxxx-xxxxxxxxxxxx / ext4 noatime,errors=remount-ro 0 0
/dev/mapper/cryptswap none swap defaults 0 0
root@work# vi /etc/fstab
root@work# cat /etc/fstab
# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point> <type> <options> <dump> <pass>
PARTUUID=949a09f0-xxxx-xxxx-xxxx-xxxxxxxxxxxx /boot/efi vfat umask=0077 0 0
PARTUUID=bbcc2068-xxxx-xxxx-xxxx-xxxxxxxxxxxx /recovery vfat umask=0077 0 0
/dev/mapper/workvg-root / ext4 noatime,errors=remount-ro 0 0
/dev/mapper/cryptswap none swap defaults 0 0
root@it05:/media/new-root/etc/initramfs-tools# lsinitramfs /boot/initrd.img-$(uname -r) | grep lvm
etc/lvm
etc/lvm/lvm.conf
etc/lvm/lvmlocal.conf
etc/lvm/profile
etc/lvm/profile/cache-mq.profile
etc/lvm/profile/cache-smq.profile
etc/lvm/profile/command_profile_template.profile
etc/lvm/profile/lvmdbusd.profile
etc/lvm/profile/metadata_profile_template.profile
etc/lvm/profile/thin-generic.profile
etc/lvm/profile/thin-performance.profile
etc/lvm/profile/vdo-small.profile
scripts/init-bottom/lvm2
scripts/local-block/lvm2
scripts/local-top/lvm-workaround
scripts/local-top/lvm2
usr/lib/udev/rules.d/56-lvm.rules
usr/lib/udev/rules.d/69-lvm-metad.rules
usr/sbin/lvm
root@it05:/# update-initramfs -u
update-initramfs: Generating /boot/initrd.img-5.19.0-76051900-generic
cryptsetup: WARNING: Resume target cryptswap uses a key file
kernelstub.Config : INFO Looking for configuration...
kernelstub.Drive : ERROR Could not find a block device for the a partition. This is a critical error and we cannot continue.
Traceback (most recent call last):
File "/usr/lib/python3/dist-packages/kernelstub/drive.py", line 56, in __init__
self.esp_fs = self.get_part_dev(self.esp_path)
File "/usr/lib/python3/dist-packages/kernelstub/drive.py", line 94, in get_part_dev
raise NoBlockDevError('Couldn\'t find the block device for %s' % path)
kernelstub.drive.NoBlockDevError: Couldn't find the block device for /boot/efi
run-parts: /etc/initramfs/post-update.d//zz-kernelstub exited with return code 174
root@it05:/# lsblk -f
NAME FSTYPE FSVER LABEL UUID FSAVAIL FSUSE% MOUNTPOINTS
sda
├─sda1
│ vfat FAT32 D499-28CF
├─sda2
│ vfat FAT32 D499-2B97
├─sda3
│ ext4 1.0 9f1f68bb-xxxx-xxxx-xxxx-xxxxxxxxxxxx
└─sda4
swap 1 1758e7a0-xxxx-xxxx-xxxx-xxxxxxxxxxxx
└─cryptswap
swap 1 cryptswap
e874c9cc-xxxx-xxxx-xxxx-xxxxxxxxxxxx [SWAP]
sdb LVM2_m LVM2 wRBz38-xxxx-xxxx-xxxx-xxxx-xxxx-xxxxxx
└─workvg-root
ext4 1.0 9f1f68bb-xxxx-xxxx-xxxx-xxxxxxxxxxxx 448.6G 46% /
root@it05:/# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/workvg-root 916G 421G 449G 49% /
tmpfs 7.8G 0 7.8G 0% /dev/shm
tmpfs 1.6G 2.4M 1.6G 1% /run
root@it05:/# mount /dev/sda1 /boot/efi
root@it05:/# update-initramfs -u
update-initramfs: Generating /boot/initrd.img-5.19.0-76051900-generic
cryptsetup: WARNING: Resume target cryptswap uses a key file
kernelstub.Config : INFO Looking for configuration...
kernelstub : INFO System information:
OS:..................Pop!_OS 22.04
Root partition:....../dev/dm-1
Root FS UUID:........9f1f68bb-xxxx-xxxx-xxxx-xxxxxxxxxxxx
ESP Path:............/boot/efi
ESP Partition:......./dev/sda1
ESP Partition #:.....1
NVRAM entry #:.......-1
Boot Variable #:.....0000
Kernel Boot Options:.quiet loglevel=0 systemd.show_status=false splash
Kernel Image Path:.../boot/vmlinuz-5.19.0-76051900-generic
Initrd Image Path:.../boot/initrd.img-5.19.0-76051900-generic
Force-overwrite:.....False
kernelstub.Installer : INFO Copying Kernel into ESP
kernelstub.Installer : INFO Copying initrd.img into ESP
kernelstub.Installer : INFO Setting up loader.conf configuration
kernelstub.Installer : INFO Making entry file for Pop!_OS
kernelstub.Installer : INFO Backing up old kernel
kernelstub.Installer : INFO Making entry file for Pop!_OSok, moment of truth, can i reboot into the new root filesystem
root@it05:/# shutdown -r now
Running in chroot, ignoring request.
root@it05:/# exit
root@work# shutdown -r nowWhoot! Success. Booted right back up, and can verify running from new LV
rhorning@icon-n.com@it05:~$ df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/workvg-root 916G 421G 449G 49% /
/dev/sda1 497M 373M 125M 76% /boot/efiNext step, add the original root partition (/dev/sda3) to the volume group so there is 1.5Gb available to the filesystem
root@work# pvcreate /dev/sda3
WARNING: ext4 signature detected on /dev/sda3 at offset 1080. Wipe it? [y/n]: y
Wiping ext4 signature on /dev/sda3.
Physical volume "/dev/sda3" successfully created.
root@work# vgextend workvg /dev/sda3
Volume group "workvg" successfully extended
root@work# vgdisplay
--- Volume group ---
VG Name workvg
System ID
Format lvm2
Metadata Areas 2
Metadata Sequence No 4
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 1
Open LV 1
Max PV 0
Cur PV 2
Act PV 2
VG Size <1.36 TiB
PE Size 4.00 MiB
Total PE 355528
Alloc PE / Size 238467 / 931.51 GiB
Free PE / Size 117061 / <457.27 GiB
VG UUID 67DSwP-xxxx-xxxx-xxxx-xxxx-xxxx-xxxxxx
root@work# lvdisplay
--- Logical volume ---
LV Path /dev/workvg/root
LV Name root
VG Name workvg
LV UUID srXpUd-xxxx-xxxx-xxxx-xxxx-xxxx-xxxxxx
LV Write Access read/write
LV Creation host, time work.example.com, 2022-10-18 08:46:34 -0400
LV Status available
# open 1
LV Size 931.51 GiB
Current LE 238467
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:0
root@work# lvextend -l +100%FREE /dev/workvg/root
Size of logical volume workvg/root changed from 931.51 GiB (238467 extents) to <1.36 TiB (355528 extents).
Logical volume workvg/root successfully resized.
root@work# lvdisplay
--- Logical volume ---
LV Path /dev/workvg/root
LV Name root
VG Name workvg
LV UUID srXpUd-xxxx-xxxx-xxxx-xxxx-xxxx-xxxxxx
LV Write Access read/write
LV Creation host, time work.example.com, 2022-10-18 08:46:34 -0400
LV Status available
# open 1
LV Size <1.36 TiB
Current LE 355528
Segments 2
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:0
root@work# df -h
Filesystem Size Used Avail Use% Mounted on
tmpfs 1.6G 2.4M 1.6G 1% /run
/dev/mapper/workvg-root 916G 421G 449G 49% /
tmpfs 7.8G 0 7.8G 0% /dev/shm
tmpfs 5.0M 0 5.0M 0% /run/lock
/dev/sda1 497M 373M 125M 76% /boot/efi
/dev/sda2 4.0G 3.4G 692M 84% /recovery
tmpfs 7.8G 0 7.8G 0% /run/qemu
tmpfs 1.6G 1.7M 1.6G 1% /run/user/1202401106
root@work# resize2fs /dev/mapper/workvg-root
resize2fs 1.46.5 (30-Dec-2021)
Filesystem at /dev/mapper/workvg-root is mounted on /; on-line resizing required
old_desc_blocks = 117, new_desc_blocks = 174
The filesystem on /dev/mapper/workvg-root is now 364060672 (4k) blocks long.
root@work# df -h
Filesystem Size Used Avail Use% Mounted on
tmpfs 1.6G 2.4M 1.6G 1% /run
/dev/mapper/workvg-root 1.4T 421G 881G 33% /
tmpfs 7.8G 0 7.8G 0% /dev/shm
tmpfs 5.0M 0 5.0M 0% /run/lock
/dev/sda1 497M 373M 125M 76% /boot/efi
/dev/sda2 4.0G 3.4G 692M 84% /recovery
tmpfs 7.8G 0 7.8G 0% /run/qemu
tmpfs 1.6G 1.7M 1.6G 1% /run/user/1202401106
References
- Move data from regular partition to lvm; Viewed on 2022-10-18
- How to Create LVM Partition in Linux – LVM Tutorial; Viewed on 2022-10-18
- 'lvextend -l 100%FREE' resizing to the number of free extents rather than adding them to the current size in RHEL; Viewed on 2022-10-18
- Best Practice for Mounting an LVM Logical Volume with /etc/fstab; Viewed on 2022-10-18
- Can't update kernel and initramfs; Viewed on 2022-1018
- Crucial MX500 1TB 3D NAND SATA 2.5-inch; Viewed on 2022-10-18
- Corsair Dual SSD Mounting Bracket (3.5” Internal Drive Bay to 2.5", Easy Installation) ; Viewed on 2022-10-18