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 Other lv on the same volume group are healthy. In fact the whole host runs on the same vg and does not show any problems. Physical volume is a md raid1 device which is also healthy, as well as its hard disks. The faulty lv is used as the storage device for a qemu vm, which suddenly stalled when the io-errors appeared on the host. Is the any way to diagnose this problem? (centos 7) Regards .....Volker
On 2017-07-06 5:43 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 > > > Other lv on the same volume group are healthy. In fact the whole host > runs on the same vg and does not show any problems. Physical volume is > a > md raid1 device which is also healthy, as well as its hard disks. > > The faulty lv is used as the storage device for a qemu vm, which > suddenly stalled when the io-errors appeared on the host. > > > Is the any way to diagnose this problem? (centos 7) > > > Regards > .....VolkerHello, Volker. Assuming that, at this point, everything that would have been running from this LV/FS is down, have you considered unmounting the filesystem and running a filesystem check against it? If it's EXT2/3/4, you can run fsck against it, if it's XFS, you can run xfs_repair against it. -- Mike Burger http://www.bubbanfriends.org "It's always suicide-mission this, save-the-planet that. No one ever just stops by to say 'hi' anymore." --Colonel Jack O'Neill, SG1
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 253:13That 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.
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?