iraf.net

>From afdhm@vela.phys.uaa.alaska.edu Mon Dec 5 17:39:56 2005
From: "Dr. Donald H. Martins" <afdhm@vela.phys.uaa.alaska.edu>
Organization: University of Alaska Anchorage
To: fitz@tucana.tuc.noao.edu
Subject: question
Date: Mon, 5 Dec 2005 15:37:44 -0900Hi, Mike.I can access the tape drive with tar and dump correctly outside
of IRAF from a normal user account. I have set all the permissions
to 666, and the /dev/st0* and /dev/nst0* are all owned by root
and in the root group. By the way, a system reboot causes the  
permissions to reset to 660.allocate works OK, but any attempt to access the drive via rewind,
rfits, wfits generates (for simple 'mta' access)Warning: Cannot open device (nst0)Any suggestions?Cheers,
DonOn Monday 05 December 2005 11:30 am, you wrote:
> Hi Don,
>  "Cannot open device" messages are usually permissions problems on
> the device, i.e. the /dev/nst0 (and aliases) must all have mode 666 (i.e.
> -rw-rw-rw-) and be owned by root.  Your tapecap entry looks fine, I'm
> assuming there are no problems accessing the drive outside of IRAF?  Hope
> this helps, let me know if the permissions change doesn't solve things.
>
> Cheers,
> Mike Fitzpatrick>From afdhm@vela.phys.uaa.alaska.edu Mon Dec 5 19:33:05 2005
To: Mike Fitzpatrick <fitz@tucana.tuc.noao.edu>
Subject: Re: question
Date: Mon, 5 Dec 2005 17:30:55 -0900Mike,A follow-up on my last message. I have experimented some more and
found out that when IRAF releases the tape devices the group is reset
to 'root' whereas the normal group is 'disk'. I need to do some more tests
but as of now I know that if I set the group to disk for st0* and nst0*
and start IRAF, I can allocate mta (simple 6200 mode), rewind, and
execute rfits without the "cannot open" message. However, rfits
does not work correctly because my data tapes are high density. Using
mta nothing displays on xtapemon. I can allocate mtb or mtbhi and the
rewind command causes information to display in xtapemon, but the
"cannot open" message appears. I presume from this that the Redhat
Linux tape driver can only handle one density??? After trying to use
mtb or mtbhi then mta no longer works at all--gives the same "cannot
open" message.thanks.
Don
>From afdhm@vela.phys.uaa.alaska.edu Wed Dec 7 16:31:46 2005
To: Mike Fitzpatrick <fitz@tucana.tuc.noao.edu>
Subject: Re: question
Date: Wed, 7 Dec 2005 14:29:28 -0900Mike,Some additional information: First, it appears that only /dev/st0
and /dev/nst0 are functional under RHEL 4ES. Both tar and dump
can only access st0 or nst0. For exampleafdhm@vela ~]$ tar -cvf /dev/st0l login.cl
login.cl
tar: /dev/st0l: Cannot write: No such device or address
tar: Error is not recoverable: exiting noweven though afdhm@vela ~]$ ls -l /dev/st0*
crw------- 1 afdhm afdhm 9, 0 Dec 5 06:30 /dev/st0
crw-rw-rw- 1 root disk 9, 96 Dec 5 06:30 /dev/st0a
crw-rw-rw- 1 root disk 9, 32 Dec 5 06:30 /dev/st0l
crw-rw-rw- 1 root disk 9, 64 Dec 5 06:30 /dev/st0mHere I listed the devices while /dev/st0 was allocated under IRAF.Using the default tapecap which comes with the distribution I get the
following output from accessing the drivecl> set tapecap = ":so=/dev/tty"
cl> allocate mtf
cl> rewind mtf
open device nst0\n
devtype = Exabyte EXB-8200 8mm tape drive
tapetype = P6-120MP
tapesize = 2347794
density = na
blksize = 0
acmode = read
file = -1
record = -1
nfiles = 0
tapeused = 0
device nst0 opened on descriptor 4\n
rewinding...
done\n
position to file 1\n
file = 1
record = 1
reading...\n
close device\n
tapeused = 0cl> wfits image.short mtf[1] ma+
open device nst0\n
devtype = Exabyte EXB-8200 8mm tape drive
tapetype = P6-120MP
tapesize = 2347794
density = na
blksize = 0
acmode = write
file = 1
record = 1
nfiles = 0
tapeused = 0
position to file 1\n
device nst0 opened on descriptor 4\n
file = 1
record = 1
writing...\n
Image 1: image.short -> mtf[1] m51 B 600s Size = 512 x 512
pixtype=short bitpix=16 blkfac=10 scaling=none
recsize = 28800
write error, status=-1, errno=22\n
2 Header File incomplete: 8 logical data (2880 byte) records written
Warning: WRT_RECORD: Error writing data record.
close device\n
tapeused = 0
Error writing file: mtf[1]
Warning: WRT_RECORD: Error writing data record.
cl> Trying to use rfits produces similar results.I am stymied on this one.To repeat, the tape drive is an Exabyte Eliant (I have two drives, one each in
two different machines with IRAF on each--identical problems). I really need
to access some old data so this is important for my work. I hope we can
figure out the problem and make it work.Thanks,
Don
>From afdhm@vela.phys.uaa.alaska.edu Wed Dec 14 16:16:30 2005
To: Mike Fitzpatrick <fitz@tucana.tuc.noao.edu>
Subject: Re: question
Date: Wed, 14 Dec 2005 13:43:59 -0900Mike,One further piece of information: wtar and rtar work fine in IRAF
with the Eliant 820 accessed as /dev/st0. The only problem is
with rfits and wfits.Cheers
Don
>From fitz@tucana.tuc.noao.edu Sat Dec 17 21:41:18 2005
Date: Sat, 17 Dec 2005 21:41:17 -0700 (MST)
From: Mike Fitzpatrick <fitz@tucana.tuc.noao.edu>
To: Mike Fitzpatrick <fitz@tucana.tuc.noao.edu>,
"Dr. Donald H. Martins" <afdhm@vela.phys.uaa.alaska.edu>
Subject: Re: question
In-Reply-To: <200512141343.59570.afdhm@vela.phys.uaa.alaska.edu>Hi Don, Sorry for the slow reply, I've been successful at ignoring
my mail these last few weeks. The tape density problem is something
that should have occurred to me earlier, we don't get many tape questions
any more. There used to be a way to configure this and the mode
automatically if you built your own kernel, or you can simply set the
variable block mode in the /etc/rc.local file as part of the boot process.
The IRAF alloc/dealloc isn't strictly required to access the tape but
should take care of the permission/ownership automatically (if you
don't see an error about the ownership of the alloc.e process then this
should be working correctly). Once you've reset the density it should
remain that way until it is changed again, I'm not aware of any behavior
that will reset it automatically.
Hope this helps.Cheers,
-Mike