Hi,
I think there is no notification mechanism available for the
"tape loaded" event. Probably the only way to wait for this
event would be to poll for the medium state with a shell
script.
Something like the following:
#/bin/bash
tape_devno=a54
tape_devnode=ntibm0
state=$(lstape | grep $tape_devno | awk '{print $8}')
while [ "$state" != "LOADED" ]; do
# Needed for 34xx drives:
# Do IO in order to update the medium state
mt -f /dev/$tape_devnode rewind 2> /dev/null
state=$(lstape | grep $tape_devno | awk '{print $8}')
sleep 2
echo "Wait for tape: $tape_devno"
done
echo "Tape loaded..: $tape_devno"
Michael
On Thu, 2010-09-02 at 17:23 +0100, Vlacil, Radek wrote:
> Hi,
>
> Thanks once more, udev works like a charm for what I asked at the first
> time. However, I have found one more much trickier problem.
>
> When a tape drive is attached to the system (just the drive, without any
> tape) uevent is generated as it should be, I can easily attach "chccwdev
> -e" to that. This generates another uevent and udev creates
> /dev/[bnr]tibmN nodes. When I issue:
>
> linux:~ # cat /dev/ntibm0
> cat: /dev/ntibm0: No medium found
>
> it says that there is no medium, what a surprise :).
>
> Now I would like to wait until a tape is actually inserted. There is no
> uevent generated for that. But in the system log:
>
> kernel: TAPE_CORE: (0.0.0181): Tape has been mounted
>
> message is displayed. Is there a way to track that?
>
> Radek Vlacil
>
>
> -----Original Message-----
> From: Linux on 390 Port [mailto:[email protected]] On Behalf Of
> Sebastian Ott
> Sent: Wednesday, September 01, 2010 18:44
> To: [email protected]
> Subject: Re: Tapes 34xx detection
>
> Hi,
>
> On Wed, 1 Sep 2010, Vlacil, Radek wrote:
> > Is there any way how to detect in an application that 34xx tape was
> > attached through ccw. In other words, detect that new directory for
> that
> > tape appeared in /sys/bus/ccw/devices/ and that it is ready for
> > "chccwdev -e". I would like to have a program that tracks whether any
> > tape was attached or detached and I was wondering whether there is
> > another option than "try-to-open and wait" loop.
>
> when a device is added/removed to/from linux the kernel will create
> "uevents" to inform userspace about these events. a daemon called
> udevd receives these events and triggers some actions. the actions
> can be specified by udev scripts.
>
> so it should be possible to extend your distributors udev scripts
> (or write your own) to e.g. write a logfile if a tape device is
> attached.
>
> if i monitor uevents i get:
> # udevmonitor --env
> ...
> UEVENT[1283357379.294644] add /devices/css0/0.0.0014/0.0.1001 (ccw)
> ACTION=add
> DEVPATH=/devices/css0/0.0.0014/0.0.1001
> SUBSYSTEM=ccw
> CU_TYPE=3990
> CU_MODEL=E9
> DEV_TYPE=3390
> DEV_MODEL=0A
> MODALIAS=ccw:t3990mE9dt3390dm0A
> SEQNUM=1643
> ...
> UEVENT[1283357406.102060] remove /devices/css0/0.0.0014/0.0.1001 (ccw)
> ACTION=remove
> DEVPATH=/devices/css0/0.0.0014/0.0.1001
> SUBSYSTEM=ccw
> CU_TYPE=3990
> CU_MODEL=E9
> DEV_TYPE=3390
> DEV_MODEL=0A
> MODALIAS=ccw:t3990mE9dt3390dm0A
> SEQNUM=1644
>
> for attaching/detaching devices (no tape, but you should get
> the idea...)
>
> regards
> sebastian
> >
> > These are messages in the system log which describes events I'd like
> to
> > trap:
> >
> >
> >
> > kernel: crw_info : CRW reports slct=0, oflw=0, chn=0, rsc=3, anc=1,
> > erc=4, rsid=5
> >
> > kernel: TAPE_CORE: tape device 0.0.0186 found
> >
> > kernel: TAPE_CORE: (0.0.0186): Tape has been mounted
> >
> > kernel: TAPE_BLOCK: Detecting media size...
> >
> > kernel: TAPE_BLOCK: Found 2 blocks on media
> >
> > kernel: TAPE_CORE: (0.0.0186): Tape is unloaded
> >
> > kernel: crw_info : CRW reports slct=0, oflw=0, chn=0, rsc=3, anc=1,
> > erc=4, rsid=5
> >
> >
> >
> > Radek Vlacil
> >
> >
> >
> >
> > ----------------------------------------------------------------------
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> > http://wiki.linuxvm.org/
> >
>
> ----------------------------------------------------------------------
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> send email to [email protected] with the message: INFO LINUX-390 or
> visit
> http://www.marist.edu/htbin/wlvindex?LINUX-390
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>
> ----------------------------------------------------------------------
> For LINUX-390 subscribe / signoff / archive access instructions,
> send email to [email protected] with the message: INFO LINUX-390 or visit
> http://www.marist.edu/htbin/wlvindex?LINUX-390
> ----------------------------------------------------------------------
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> http://wiki.linuxvm.org/
----------------------------------------------------------------------
For LINUX-390 subscribe / signoff / archive access instructions,
send email to [email protected] with the message: INFO LINUX-390 or visit
http://www.marist.edu/htbin/wlvindex?LINUX-390
----------------------------------------------------------------------
For more information on Linux on System z, visit
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