mount: unknown filesystem type ‘LVM2_member’

Categories: Linux, OS

i foobar’d a fedora 4 machine a couple of days ago and when i went to mount the disk into another machine i get this beautiful error:

mount: unknown filesystem type 'LVM2_member'

here was the syntax used:

termcb:~ # mount /dev/hda2 /mnt/old/
mount: unknown filesystem type 'LVM2_member'

and here was the drive :

termcb:~ # fdisk -l

Disk /dev/hda: 30.0 GB, 30005821440 bytes
255 heads, 63 sectors/track, 3648 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System
/dev/hda1 * 1 13 104391 83 Linux
/dev/hda2 14 3648 29198137+ 8e Linux LVM

so using lvm2 tools, we do a disk scan:

termcb:~ # lvmdiskscan
/dev/ram0 [ 62.50 MB]
/dev/ram1 [ 62.50 MB]
/dev/hda1 [ 101.94 MB]
/dev/sda1 [ 39.19 MB]
/dev/ram2 [ 62.50 MB]
/dev/hda2 [ 27.85 GB] LVM physical volume
/dev/sda2 [ 2.01 GB]
/dev/ram3 [ 62.50 MB]
/dev/sda3 [ 60.00 GB]
/dev/ram4 [ 62.50 MB]
/dev/sda4 [ 86.96 GB]
/dev/ram5 [ 62.50 MB]
/dev/ram6 [ 62.50 MB]
/dev/ram7 [ 62.50 MB]
/dev/ram8 [ 62.50 MB]
/dev/ram9 [ 62.50 MB]
/dev/ram10 [ 62.50 MB]
/dev/ram11 [ 62.50 MB]
/dev/ram12 [ 62.50 MB]
/dev/ram13 [ 62.50 MB]
/dev/ram14 [ 62.50 MB]
/dev/ram15 [ 62.50 MB]
0 disks
21 partitions
0 LVM physical volume whole disks
1 LVM physical volume

then we do a lvdisplay so we can get the LV Name and VG Name:

termcb:~ # lvdisplay
--- Logical volume ---
LV Name /dev/VolGroup00/LogVol00
VG Name VolGroup00
LV UUID WBjpH6-Jezl-aI1z-XVSp-WzvW-qTDi-c1jkUv
LV Write Access read/write
LV Status NOT available
LV Size 26.06 GB
Current LE 834
Segments 1
Allocation inherit
Read ahead sectors 0

--- Logical volume ---
LV Name /dev/VolGroup00/LogVol01
VG Name VolGroup00
LV UUID Zykaw3-WBHU-oink-38W9-KylN-7u5j-PKx8qT
LV Write Access read/write
LV Status NOT available
LV Size 1.75 GB
Current LE 56
Segments 1
Allocation inherit
Read ahead sectors 0

and also a vgdisplay to make sure it was the right drive:

termcb:~ # vgdisplay
--- Volume group ---
VG Name VolGroup00
System ID
Format lvm2
Metadata Areas 1
Metadata Sequence No 3
VG Access read/write
VG Status resizable
Cur LV 2
Open LV 0
Max PV 0
Cur PV 1
Act PV 1
VG Size 27.84 GB
PE Size 32.00 MB
Total PE 891
Alloc PE / Size 890 / 27.81 GB
Free PE / Size 1 / 32.00 MB
VG UUID ryYRi4-mXOd-XFaW-4xnR-h1cl-hphh-5QQnlM

so at this point i re-tried to mount but using the VG Name:

termcb:~ # mount /dev/VolGroup00/LogVol00 /mnt/old/
mount: special device /dev/VolGroup00/LogVol00 does not exist

still failure

so i did an lvscan next to see what the status of the lv drive is:

termcb:~ # lvscan
inactive '/dev/VolGroup00/LogVol00' [26.06 GB] inherit
inactive '/dev/VolGroup00/LogVol01' [1.75 GB] inherit

fuck…. still inactive
thats when i stumbled across this post : … 64964.html

now the rest was pretty self explanatory:

modprobe dm-mod

vgchange -ay

termcb:~ # lvscan
ACTIVE '/dev/VolGroup00/LogVol00' [26.06 GB] inherit
ACTIVE '/dev/VolGroup00/LogVol01' [1.75 GB] inherit

mount /dev/VolGroup00/LogVol00 /mount/point


this was done on a suse 10.1 box trying to mount a fedora 4 drive.

if this was gentoo it probably would have been much easier.

  • Hi!

    Actually, this article helped me a lot in creating a backup from my Fedora installation using SysRescCd.


    • I was getting the mount: unknown filesystem type ‘LVM2_member’ as well. Turns out I was trying to map the physical device’s partition (ie, /dev/sdc1) instead of the LVM’s logical? one (ie, /dev/mapper/data-home or /dev/dm-1). Chances are good that the device names are different on your system than on mine just for the heads up. I’m Ubuntu 10.10. In the process of switching to Gentoo. Best of luck.

  • Hi this is helpful but when I mount a root partition like “/dev/system/root_lv” it won’t work.. no display error but not working.. any ideas?

  • Well done, this helped us recover a snapshot from EBS after the recent AWS EU black out. Many thanks!

  • I thought I had lost all my data, but thanks to your blog and some common sense I managed to recover the complete (Debian!) LVM partition.
    Thanks !!!

  • You are an Internet BOSS for this article. Some hardware became unstable and would not allow me to rsync the data to another host. Ran into this error when I moved the drive to a stable host. I really need to work on my volume management skills. Thanks!

    Send me a bitcoin address and I’ll give you a little something.

  • Kewl now please tell me why I cant mount as /opt folder … To add Extra space. Iff i mount it mount /dev/VolGroup00/LogVol01 /opt then i have my extendex /opt drive messed up with / folders.


  • [root@lnx /]# mount /dev/VolGroup00/LogVol01 /opt/
    /dev/VolGroup00/LogVol01 looks like swapspace – not mounted
    mount: you must specify the filesystem type

  • 🙂
    saved me as well.
    Now I know why my old system always behaved so strangely when mounting this disk. I never did it by hand and now had to. Additionally it was in a cryptfs container but that I knew how to deal with.

  • Thanks a ton, I needed one of the drives off an old raid and wanted to mirror the contents before formating this helped a ton!! I will no longer be using logic volumes in my installs.

  • Beautiful!

    I followed the solution by mounting 127 GB Fedora 15 partition on a 300 GB
    SATA drive that also has a 163 GB Windows partition. Somehow the Windows
    partition was being seen but not the Fedora one.

    This came in handy and all were done on an Ubuntu 11.10 OS which
    is a partition on a Mac OS X McBookPro1,1 running Snow Leopard!


  • Thanks a lot!!!
    You also rescued my HDD and info. God bless you!
    I mounted my ex hdd installed Linux which sees it LVM2_member. Fortunately recognized it as home swap and root.

  • thanks…
    I have mount lvm volume on ubuntu 10.10 that way… mounted successfully.. but due to older volume user is different than current user where i have mounted this volume… so it is giving permission denied even for “sudo” ….. how can I solve without affecting any permission structure on older volume…

  • You truly are a hero, Ive spent the last 2 days trying to mount that stupid encrypted LV, and it was that simple!!!

  • Hi and thanks for your post.
    I’ve followed the instructions, using a Knoppix live CD to recover my 1 To HDD. It went well, I could read the files, but knoppix gets very slow, and I wasn’t able
    I then reboot Knoppix, to try and copy one file on a usb drive, but now I CAN’T SEE my disk even using “fdisk -l”.

    More Details:
    In deed, my HDD is a 1 To HDD from a NAS iomega ix2 Storcenter, configure in RAID 1 with another 1 To HDD. One of the disk went down and we were not able to access the files over the network interface.
    1-I took the working HDD and connected it to a laptop using SATA-to USB
    2-I first tried to acces the HDD in degraded RAID 1, but it keeps telling “unkown file system linux_RAID_member”
    3-The “file -s” command allow me to notice that it was a Linux LVM device.
    4- I then change the device ID from Linux (ID 83) to Linux LVM (ID 8e)
    5- Then I follow your instruction to restore the metadata and VG configuration

    It all works fine till the problem mentionned above.

    ANY SUGGESTIONS? Thoughts?

  • man you saved my life….
    struggled 1 day, already thought all my data is gone…was not able to mount my readynas disks until i read this post.


  • On Ubuntu 10.10. Everything seems to work great, until the final mount, which STILL wants me to specify the filesystem type. Any thoughts?

  • Many thanks, I can now access the RAW file!
    I tried to replicate my dynamic VDI UBUNTU SERVER 64 BIT hard disk via my linux live usb stick.
    Ι get this :
    ACTIVE ‘/dev/ubuntu/root’ [23.65 GiB] inherit
    ACTIVE ‘/dev/ubuntu/swap_1′ [1.65 GiB] inherit

    I managed to mount the root partition (not the swap) but the command
    dd if=/dev/ubuntu/root of=/dev/sdc2 bs=1M
    as proposed by many sites does not work.
    The empty ext4 partitions dc2 needs to be formatted then , it becomes junk after the whole dd procedure.
    Which method should I use so as to replicate the system
    on a new partition?
    dd? What a terrible tool! any ideas for parameters? What I tried so far was rubbish .
    Some other utility?
    Please help! THANKS

    • I got the answer for the correct dd parameters here:

      But still, I cannot successfully boot from the new resulting partition which includes the entire system from the partition of the LVM ( I also rendered the new partition as the boot partition via gparted).
      maybe the ACTIVE ‘/dev/ubuntu/swap_1′ [1.65 GiB]
      is also needed??????

      here are the instructions for dd in order to correctly replicate a single partition:
      ( I successfully followed these instructions)

      From physical disk /dev/sda, partition 1, to physical disk /dev/sdb, partition 1.

      dd if=/dev/sda1 of=/dev/sdb1 bs=4096 conv=notrunc,noerror

      If output file of (sdb1 in the example) does not exist, dd will start at the beginning of the disk and create it.
      Cloning an entire hard disk

      From physical disk /dev/sda to physical disk /dev/sdb

      dd if=/dev/sda of=/dev/sdb bs=4096 conv=notrunc,noerror

      This will clone the entire drive, including MBR (and therefore bootloader), all partitions and data.

      notrunc or ‘do not truncate’ maintains data integrity by instructing dd not to truncate any data.
      noerror instructs dd to continue operation, ignoring all input errors. Default behavior for dd is to halt at any error.
      bs=4096 sets the block size to 4k, an optimal size for hard disk read/write efficiency and therefore, cloning speed.

  • Dood you are a rock star. During unemployment my hd crashed, but fortunately I had good partitioning. I could see this when I tried to reload Linux, apparently the / partition was toasted. So I bought a new drive, put the old one in this iMicro case and tried to read it. The LVM2 error.

    Now I still have my unemployment records in case I get audited! Thanks so much for all the help!

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