[CentOS] logical volume is unreadable

[Robert Nichols]

On 07/06/2017 04:43 AM, Volker wrote:
> Hi all,
> 
> one of my lv has become completely unaccessible. Every read access
> results in a buffer io error:
> 
> Buffer I/O error on dev dm-13, logical block 0, async page read
> 
> this goes for every block in the lv. A ddrescue failed on every single
> block.
> 
> 
> $ lvdisplay
>    --- Logical volume ---
>    LV Path                /dev/vg0/lv-vm-tviewer
>    LV Name                lv-vm-tviewer
>    VG Name                vg0
>    LV UUID                XdgHFs-RHVZ-9BAH-1ZSK-yiBX-qqf0-273CtT
>    LV Write Access        read/write
>    LV Creation host, time host1, 2016-02-06 14:58:19 +0100
>    LV snapshot status     INACTIVE destination for lv-vm-tviewer_vorigin
>    LV Status              available
>    # open                 0
>    LV Size                58.59 GiB
>    Current LE             15000
>    COW-table size         5.86 GiB
>    COW-table LE           1500
>    Snapshot chunk size    4.00 KiB
>    Segments               1
>    Allocation             inherit
>    Read ahead sectors     auto
>    - currently set to     8192
>    Block device           253:13

That looks like a snapshot volume that became invalid because it was filled to capacity. Such a snapshot is lost forever. It si your responsibility to monitor snapshot usage to make sure it does not run out of space. The base volume, lv-vm-tviewer_vorigin, should still have its original content.

-- 
Bob Nichols     "NOSPAM" is really part of my email address.
                 Do NOT delete it.