Unusable LV, how to unlock it?

Hi there,

Just now one of my LVs became unusable, as in every operation done on its mounted filesystem just blocks forever.

I believe it is still mounted however that is inside a Xen domain that no longer exists so I don't know how to confirm that.

Based on previous advice I tried to run "dmsetup info -c" and "lvs -v" to compare results, but "lvs -v" also gets stuck here:

[andy@curacao andy]$ sudo lvs -v
Finding all logical volumes

I believe the "stuck" LV is /dev/mapper/mainvg-adminroot.

Anyone have any suggestions how I can get use of this LV again without rebooting? Here is the output from "dmsetup info -c":

[andy@curacao andy]$ sudo dmsetup info -c
Name Maj Min Stat Open Targ Event UUID

mainvg-snapoutpostlonthlroot 254  18 L--w    0    1      0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW43KIFDMhuc66kGoKopCggfSa4ijWQCF1B
mainvg-snapcholetroot 254  28 L--w    0    1      0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW48TFpObhJOO6dcjNdwBMNL1IxV5AvbUaK
mainvg-snaphomelv-cow 254   3 L--w    1    1      0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW4ft5n3X4Wesr501vvlHBdydbx31jkfKMV-cow
mainvg-saffronswap 254  50 L--w    1    1      0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW4zSKpfytAZ9EUG4rqIvZABneBhuWRkxht
mainvg-saffronroot 254  49 L--w    1    1      0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW40HQxP1U2QHGJ7cYPF7rtRD0sLiLYFucm
mainvg-ruminantswap 254  45 L--w    1    1      0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW4YLA67yfx2jRo4tylP31c127lFMxVKXqB
mainvg-ruminantroot 254  44 L--w    1    1      0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW4NolJn0Zj9cLM4kMcNIW1nGAE6LWbphJz

mainvg-usrlv 254 0 L--w 1 1 0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW4mT2ApHrAfpAnDCWjRGAzyrY145rJMmcD
mainvg-snapoutpostlonthlroot-cow 254 17 L--w 1 1 0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW43KIFDMhuc66kGoKopCggfSa4ijWQCF1B-cow
mainvg-snapcholetroot-cow 254 26 L--w 1 1 0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW48TFpObhJOO6dcjNdwBMNL1IxV5AvbUaK-cow
mainvg-ruminantdata 254 46 L--w 1 1 0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW4hbYSoa2T5XuNRw73bU5BOXmTBDv6ibVX
mainvg-strugglersroot-real 254 12 L--w 2 1 0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW43jwledji1nh8rtcbheq8MUU1vi937zDK-real
mainvg-blueswap 254 48 L--w 1 1 0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW4RjnFTRybYJqK8drln4HzMYWnbfk33aSu
mainvg-seinfeldswap 254 25 L--w 1 1 0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW4XScAry8eVwasTOLeIh6HfGSHim3fIuv9

mainvg-snapseinfeldroot-cow 254  22 L--w    1    1      0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW4yh6e80ZEQafHKSe4jo6ydJWe1T0A1lkj-cow
mainvg-blueroot  254  47 L--w    1    1      0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW4Xx1o20L4fpev6EU5wMB6mHhayQsnRLQg
mainvg-adminswap 254  43 L--w    0    1      0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW48Q2Z20jIewK2Vdt47Kn4IO6KBI28PIAm
mainvg-seinfeldroot 254  24 L--w    1    1      0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW43BT9T40cl5HYYg3j1QIwfp5hc0LIqUsI
mainvg-adminroot 254  38 L--w    1    1      0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW4CjHGy8QpGKoH35P5U58Di1NKeYspeIR2
mainvg-admindata 254  42 L--w    0    1      0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW4cCHdlPbllQNt50aJANhLrqbjUkK7jCsP
mainvg-tmplv     254   2 L--w    1    1      0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW4tfVsPETP9bimi535hqeX6Ch1yhYGePxS
mainvg-admindata-real 254  39 L--w    2    1      0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW4cCHdlPbllQNt50aJANhLrqbjUkK7jCsP-real

mainvg-snapstrugglersroot 254 13 L--w 0 1 0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW41yOu8xefQnL6FK69xAojAvXYqLcAlI0g
mainvg-snaphomelv 254 5 L--w 0 1 0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW4ft5n3X4Wesr501vvlHBdydbx31jkfKMV
mainvg-outpostlonthlroot-real 254 16 L--w 2 1 0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW4oTAjSEuyiaawrNF6iUbSrZqzWCHqOW1P-real
mainvg-snapstrugglersdata 254 33 L--w 0 1 0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW4gKZfk2xyEo6749X1uLWyPhxF3tP8sfvM
mainvg-choletroot-real 254 27 L--w 2 1 0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW4ZlGfn0e2THSlmotbck1bJBEPr12ngi7r-real
mainvg-seinfeldroot-real 254 21 L--w 2 1 0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW43BT9T40cl5HYYg3j1QIwfp5hc0LIqUsI-real
mainvg-strugglersswap 254 15 L--w 1 1 0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW43CcBI91LrT914eNMDyzhdYjym0rVQTsF
mainvg-outpostlonthlswap 254 20 L--w 1 1 0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW4BR8eDYVYzQJXlGPplq1YKB27p7h3HtZV
mainvg-strugglersroot 254 14 L--w 1 1 0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW43jwledji1nh8rtcbheq8MUU1vi937zDK
mainvg-outpostlonthlroot 254 19 L--w 1 1 0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW4oTAjSEuyiaawrNF6iUbSrZqzWCHqOW1P

mainvg-homelv    254   6 L--w    1    1      0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW4cd3BqQaBDxmVgo7X37SYp33yQBeOA0n0
mainvg-strugglersdata 254  34 L--w    1    1      0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW4gp5msGLmNEROJHmToKkpBxe8SC8I7xQ6
mainvg-varlv     254   1 L--w    1    1      0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW4z0sYK4fz3qSmLuXYIvjR3y0Nt22DgsCB
mainvg-snapdatalv 254   9 L--w    0    1      0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW4HAJcH84mtd6DzqhjIxPsZGM0fhFKIp9B
mainvg-adminroot-real 254  36 L--w    2    1      0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW4CjHGy8QpGKoH35P5U58Di1NKeYspeIR2-real
mainvg-choletswap 254  30 L--w    1    1      0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW47YXxUIkZdkdioRs7QxsBBJXFa0jslAWS
mainvg-choletroot 254  29 L--w    1    1      0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW4ZlGfn0e2THSlmotbck1bJBEPr12ngi7r

mainvg-homelv-real 254 4 L--w 2 1 0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW4cd3BqQaBDxmVgo7X37SYp33yQBeOA0n0-real
mainvg-snapstrugglersroot-cow 254 11 L--w 1 1 0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW41yOu8xefQnL6FK69xAojAvXYqLcAlI0g-cow
mainvg-datalv 254 10 L--w 1 1 0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW4OesUvyDaFU9O4jKDhPlChy4LpwYAMoe4
mainvg-snapadminroot 254 37 L--w 0 1 0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW46RYghmBICie3mZ3GbWDWt4L2rziM1iuc
mainvg-snapstrugglersdata-cow 254 32 L--w 1 1 0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW4gKZfk2xyEo6749X1uLWyPhxF3tP8sfvM-cow
mainvg-snapseinfeldroot 254 23 L--w 0 1 0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW4yh6e80ZEQafHKSe4jo6ydJWe1T0A1lkj
mainvg-snapadmindata 254 41 L--w 0 1 0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW4MifVzYFYKQGTZDyn3ZxjL7CLyh70DrxK
mainvg-strugglersdata-real 254 31 L--w 2 1 0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW4gp5msGLmNEROJHmToKkpBxe8SC8I7xQ6-real
mainvg-snapadminroot-cow 254 35 L--w 1 1 0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW46RYghmBICie3mZ3GbWDWt4L2rziM1iuc-cow
mainvg-datalv-real 254 7 L--w 2 1 0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW4OesUvyDaFU9O4jKDhPlChy4LpwYAMoe4-real
mainvg-snapdatalv-cow 254 8 L--w 1 1 0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW4HAJcH84mtd6DzqhjIxPsZGM0fhFKIp9B-cow
mainvg-snapadmindata-cow 254 40 L--w 1 1 0 PqzqVKCpoXCXe6QAIW4C32bS66OoLnW4MifVzYFYKQGTZDyn3ZxjL7CLyh70DrxK-cow

It seems odd to me that any of the LVs above with "snap" in their name show an open count since I don't have any of them mounted currently.

Kernel 2.6.11 with Xen patches (2.0.6).

Thanks,
Andy

OK, so after removing a lock file I can run lvs again:

$ sudo lvs -v mainvg/adminroot
    Finding all logical volumes
  LV                VG     #Seg Attr   LSize   Maj Min KMaj KMin Origin Snap%  Move Copy%  LV UUID                            
  admindata         mainvg    1 -wi-a-   5.86G  -1  -1 254  42                             cCHdlP-bllQ-Nt50-aJAN-hLrq-bjUk-K7jCsP
  adminroot         mainvg    1 -wi-ao 500.00M  -1  -1 254  38                             CjHGy8-QpGK-oH35-P5U5-8Di1-NKeY-speIR2
  adminswap         mainvg    1 -wi-a- 256.00M  -1  -1 254  43                             8Q2Z20-jIew-K2Vd-t47K-n4IO-6KBI-28PIAm

LV 'adminroot' is not mounted anywhere, yet it is marked as open. Any time I do try to mount it, the mount process gets stuck in stat D+. Neither lvs nor dmsetup info show any snapshots of this LV. lvchange gives the following:

$ sudo lvchange -v --refresh mainvg/adminroot
    Using logical volume(s) on command line
    Refreshing logical volume "adminroot" (if active)
    Found volume group "mainvg"
  device-mapper ioctl cmd 6 failed: Invalid argument
  Couldn't suspend device 'mainvg-adminroot'

I've scheduled a reboot in about 4 hours anyway.

Thanks,
Andy

Cut and paste error, the below is actually the output of:

$ sudo lvs -v | egrep '(LV|admin)'

before anyone gets even more confused.