Hi, Well this is not a great news, but thanks anyway.
Wouldn't it be possible to implement an enhancement that would generate an uevent with ACTION="change" for this "tape loaded" kind of events? If there is a massage for that generated in the system log, it shouldn't be that hard :-). Radek Vlacil -----Original Message----- From: Linux on 390 Port [mailto:[email protected]] On Behalf Of Michael Holzheu Sent: Friday, September 03, 2010 10:30 To: [email protected] Subject: Re: Tapes 34xx detection 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 > > > > > > > > > > ---------------------------------------------------------------------- > > 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 > > 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 > 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 > 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 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 http://wiki.linuxvm.org/
