[CentOS] logical volume is unreadable

[Volker]

On 06.07.2017 15:35, Robert Nichols wrote:
> 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.
> 

That's it. Thanks for the information.

How would I remove the only the snapshot but not the base volume? Will

$ lvremove /dev/vg0/lv-vm-tviewer

leave the base volume untouched?