munin-cron does not generate image for nvme plugin read/write bytes

[solsTiCe d'Hiver]

I installed the nvme plugin and configure it to run.

I got the graph for writecycles or usage generated automatically by munin-cron
But even though there is a nvme_bytes.html generated there is no nvme_bytes-day.png generated ever. Or nvme_bytes-week.png, either.

There is a broken image link in the index page of the host in question.

[Lars Kruse]

I guess, that you can find some kind of error messages in /var/log/munin/munin-cgi-graph.log?

Does munin-run nvme (or nvme_bytes?) emit reasonable output?

[solsTiCe d'Hiver]

Well, I don't have a /var/log/munin/munin-cgi-graph.log but a /var/log/munin/munin-graph.log

What is standing out is the error:

2021/01/24 00:02:02 [RRD ERROR] Unable to graph /srv/http/munin/rhea/rhea/nvme_bytes-year.png : undefined vname cXXXXXXXXXXXXXXX_r

The complete output is:

2021/01/24 00:02:02 [RRD ERROR] rrdtool 'graph' '/srv/http/munin/rhea/rhea/nvme_bytes-year.png' \
        '--title' \
        'NVME Bytes Read / Written - by year' \
        '--start' \
        '-400d' \
        '--vertical-label' \
        'bytes read (-) / written (+) per second'' \
        '--slope-mode' \
        '--height' \
        '175' \
        '--width' \
        '400' \
        '--imgformat' \
        'PNG' \
        '--lazy' \
        '--font' \
        'DEFAULT:0:DejaVuSans,DejaVu Sans,DejaVu LGC Sans,Bitstream Vera Sans' \
        '--font' \
        'LEGEND:7:DejaVuSansMono,DejaVu Sans Mono,DejaVu LGC Sans Mono,Bitstream Vera Sans Mono,monospace' \
        '--color' \
        'BACK#F0F0F0' \
        '--color' \
        'FRAME#F0F0F0' \
        '--color' \
        'CANVAS#FFFFFF' \
        '--color' \
        'FONT#666666' \
        '--color' \
        'AXIS#CFD6F8' \
        '--color' \
        'ARROW#CFD6F8' \
        '--border' \
        '0' \
        '-W' \
        'Munin 2.0.66' \
        'DEF:a6c34d9d63098c24=/var/lib/munin/rhea/rhea-nvme_bytes-_XXXXXXXXXXXXXX_w-d.rrd:42:MAX' \
        'DEF:i6c34d9d63098c24=/var/lib/munin/rhea/rhea-nvme_bytes-_XXXXXXXXXXXXXX_w-d.rrd:42:MIN' \
        'DEF:g6c34d9d63098c24=/var/lib/munin/rhea/rhea-nvme_bytes-_XXXXXXXXXXXXXX_w-d.rrd:42:AVERAGE' \
        'DEF:ad4442274191328a=/var/lib/munin/rhea/rhea-nvme_bytes-_XXXXXXXXXXXXXX_r-d.rrd:42:MAX' \
        'DEF:id4442274191328a=/var/lib/munin/rhea/rhea-nvme_bytes-_XXXXXXXXXXXXXX_r-d.rrd:42:MIN' \
        'DEF:gd4442274191328a=/var/lib/munin/rhea/rhea-nvme_bytes-_XXXXXXXXXXXXXX_r-d.rrd:42:AVERAGE' \
        'CDEF:cd4442274191328a=gd4442274191328a,POP,UNKN' \
        'CDEF:c6c34d9d63098c24=g6c34d9d63098c24,POP,UNKN' \
        'COMMENT:            ' \
        'COMMENT:Cur (-/+)' \
        'COMMENT:Min (-/+)' \
        'COMMENT:Avg (-/+)' \
        'COMMENT:Max (-/+) \j' \
        'LINE1:g6c34d9d63098c24#00CC00:/dev/nvme0n1 ' \
        'GPRINT:cXXXXXXXXXXXXXXX_r:LAST:%6.2lf%s/\g' \
        'GPRINT:c6c34d9d63098c24:LAST:%6.2lf%s' \
        'GPRINT:iXXXXXXXXXXXXXXX_r:MIN:%6.2lf%s/\g' \
        'GPRINT:i6c34d9d63098c24:MIN:%6.2lf%s' \
        'GPRINT:gXXXXXXXXXXXXXXX_r:AVERAGE:%6.2lf%s/\g' \
        'GPRINT:g6c34d9d63098c24:AVERAGE:%6.2lf%s' \
        'GPRINT:aXXXXXXXXXXXXXXX_r:MAX:%6.2lf%s/\g' \
        'GPRINT:a6c34d9d63098c24:MAX:%6.2lf%s\j' \
        'CDEF:re_zero=gXXXXXXXXXXXXXXX_r,UN,0,0,IF' \
        'CDEF:ngXXXXXXXXXXXXXXX_r=gXXXXXXXXXXXXXXX_r,-1,*' \
        'LINE1:ngXXXXXXXXXXXXXXX_r#00CC00' \
        'LINE1:re_zero#000000' \
        'VRULE:1611441306#999999' \
        'COMMENT:Last update\: Sat Jan 23 23\:35\:06 2021\r' \
        '--end' \
        '1611360000'

But munin-run nvme on the host, gives:

multigraph nvme_usage
XXXXXXXXXXXXXXX.value 61.9291370071183
multigraph nvme_bytes
XXXXXXXXXXXXXXX_r.value 853387
XXXXXXXXXXXXXXX_w.value 683796
multigraph nvme_writecycles
XXXXXXXXXXXXXXX.value 1.40007818923458

[solsTiCe d'Hiver]

ok. this works fine in munin 2.0.67

[Lars Kruse]

Thank you for verifying the fix!