<div dir="ltr">Hi there,<div><br></div><div>I noticed that there is a transient and benign (I can't discern any adverse effects) error reported by lvs after running lvchange --discards passdown. I wrote a simple script that eventually reproduces it (at the bottom of the email).</div>
<div><br>I have also been performing these tests *without* thin_check being enabled on volume activation. I don't know if it makes any difference, but with thin_check I noticed that I frequently get device busy errors or that lvchange can't change the state of an active volume (even though lvchange -a n is issued for the pool beforehand).</div>
<div><br></div><div>The error itself is: <font color="#484848" style="background-color:rgb(250,250,250)"><span style="font-size:12px">dm_report_object: report function failed for field data_percent. The output of the lvs command at that point is:</span></font><br>
<div style="background-color:rgb(250,250,250)"><font color="#484848"><span style="font-size:12px">LV VG Attr LSize Pool Origin Data% Move Log Copy% Convert</span></font></div>
<div style="background-color:rgb(250,250,250)"><font color="#484848"><span style="font-size:12px">TrollVolume TrollGroup Vwi-i-tz- 23.90g pool </span></font></div><div style="background-color:rgb(250,250,250)">
<font color="#484848"><span style="font-size:12px">pool TrollGroup twi-a-tz- 23.90g 2.60 </span></font></div><div style="background-color:rgb(250,250,250)">
<font color="#484848"><span style="font-size:12px">troll_snapshot_3_11_941fa1b380d748c5a5ee446ee5817960 TrollGroup Vwi---tz- 23.90g pool TrollVolume </span></font></div><div style="background-color:rgb(250,250,250)">
<font color="#484848"><span style="font-size:12px">troll_snapshot_3_13_e48750c4c0cc47e88a80f278cee8616d TrollGroup Vwi---tz- 23.90g pool TrollVolume </span></font></div><div style="background-color:rgb(250,250,250)">
<font color="#484848"><span style="font-size:12px">troll_snapshot_3_14_075ec8acaebb4964a1afa62c53fff7de TrollGroup Vwi---tz- 23.90g pool TrollVolume </span></font></div><div style="background-color:rgb(250,250,250)">
<font color="#484848"><span style="font-size:12px">troll_snapshot_3_17_59135a4db9c74fc8bb78346d976b6ba2 TrollGroup Vwi---tz- 23.90g pool TrollVolume </span></font></div><div style="background-color:rgb(250,250,250)">
<font color="#484848"><span style="font-size:12px">troll_snapshot_3_19_965c49f78f504e1cbe897f7de8c2e07d TrollGroup Vwi---tz- 23.90g pool TrollVolume </span></font></div><div style="background-color:rgb(250,250,250)">
<font color="#484848"><span style="font-size:12px">troll_snapshot_3_4_e77e18ec7faf4b8b987999588d3e01b7 TrollGroup Vwi---tz- 23.90g pool TrollVolume </span></font></div><div style="background-color:rgb(250,250,250)">
<font color="#484848"><span style="font-size:12px">troll_snapshot_3_5_d50e703f9cd94a1c93d77055fe4db2a8 TrollGroup Vwi---tz- 23.90g pool TrollVolume </span></font></div><div style="background-color:rgb(250,250,250)">
<font color="#484848"><span style="font-size:12px">troll_snapshot_3_7_80f0c30ae46e4bc696b650327b9923a0 TrollGroup Vwi---tz- 23.90g pool TrollVolume</span></font></div><div style="background-color:rgb(250,250,250)"><font color="#484848"><span style="font-size:12px"><br>
</span></font></div><div style="background-color:rgb(250,250,250)"><font color="#484848"><span style="font-size:12px">Note that the first volume, TrollVolume, is in the inactive table state (</span></font><span style="font-size:12px;background-color:rgb(255,255,255)"><font color="#484848">mapped device present with (i)nactive table). It looks like it's transitioning into the active state at this point and there seems to be a race?</font></span></div>
<div style="background-color:rgb(250,250,250)"><span style="font-size:12px;background-color:rgb(255,255,255)"><font color="#484848"><br></font></span></div><div><font color="#484848"><span style="font-size:12px;background-color:rgb(255,255,255)">I'm doing all of this with kernel 3.8.0-32-generic on Ubuntu 12.04 LTS (lvm tools were backported to the 12.04 release).</span></font></div>
<div style="background-color:rgb(250,250,250)"><span style="font-size:12px;background-color:rgb(255,255,255)"><font color="#484848"><br></font></span></div><div style="background-color:rgb(250,250,250)"><span style="font-size:12px;background-color:rgb(255,255,255)"><font color="#484848">Does anyone know if this is a known issue and whether an upgrade to a newer version of lvm tools (or kernel) would fix this?</font></span></div>
<div style="background-color:rgb(250,250,250)"><span style="font-size:12px;background-color:rgb(255,255,255)"><font color="#484848"><br></font></span></div><div style="background-color:rgb(250,250,250)"><span style="font-size:12px;background-color:rgb(255,255,255)"><font color="#484848">One more question: I observe that lvchange --discards passdown activates the pool and all volumes in it. It seems that one does not have to explicitly do lvchange -a y after disabling the volumes and issuing lvchange --discards. Does that seem right? I couldn't find any documentation about this, however.</font></span></div>
<div style="background-color:rgb(250,250,250)"><span style="font-size:12px;background-color:rgb(255,255,255)"><font color="#484848"><br></font></span></div><div style="background-color:rgb(250,250,250)"><span style="font-size:12px;background-color:rgb(255,255,255)"><font color="#484848">Thank you,</font></span></div>
<div style="background-color:rgb(250,250,250)"><span style="font-size:12px;background-color:rgb(255,255,255)"><font color="#484848">Timur</font></span></div><div style="background-color:rgb(250,250,250)"><span style="font-size:12px;background-color:rgb(255,255,255)"><font color="#484848"><br>
</font></span></div><div style="background-color:rgb(250,250,250)"><span style="font-size:12px;background-color:rgb(255,255,255)"><font color="#484848">The script:</font></span></div><div style="background-color:rgb(250,250,250)">
<span style="font-size:12px;background-color:rgb(255,255,255)"><font color="#484848"><br></font></span></div><div style="background-color:rgb(250,250,250)"><span style="font-size:12px;background-color:rgb(255,255,255)"><font color="#484848"><div style="background-color:rgb(250,250,250)">
#!/bin/bash</div><div style="background-color:rgb(250,250,250)"><br></div><div style="background-color:rgb(250,250,250)">set -e</div><div style="background-color:rgb(250,250,250)"><br></div><div style="background-color:rgb(250,250,250)">
while true; do</div><div style="background-color:rgb(250,250,250)"> echo 'deactivate'</div><div style="background-color:rgb(250,250,250)"> # /tmp/volumes is populated with the output of ls /dev/test_group</div>
<div style="background-color:rgb(250,250,250)"> for i in `cat /tmp/volumes`; do sudo lvchange -a n test_group/$i; done</div><div style="background-color:rgb(250,250,250)"> echo 'ignore'<br></div><div style="background-color:rgb(250,250,250)">
sudo lvchange --discards ignore test_group/pool</div><div style="background-color:rgb(250,250,250)"> echo 'passdown'</div><div style="background-color:rgb(250,250,250)"> sudo lvchange --discards passdown test_group/pool</div>
<div style="background-color:rgb(250,250,250)"> echo 'lvs'</div><div style="background-color:rgb(250,250,250)"> sudo lvs</div><div style="background-color:rgb(250,250,250)"> echo 'activate'</div>
<div style="background-color:rgb(250,250,250)"> for i in `cat /tmp/volumes`; do sudo lvchange -a y test_group/$i; done</div><div style="background-color:rgb(250,250,250)">done</div></font></span></div></div></div>