STE3

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Accessing data taken on the imag40 machine

  • To access data taken on the imag40 machine open up a terminal on the thin client in the 1.0m and go to (assuming today was 2015 Oct 8):
/data/40in/imag40/2015/1008
  • Alternatively you can connect via a remote machine (your Linux laptop for instance) using:
ssh ccd40@ltsp.suth.saao.ac.za
cd /data/40in/imag40/2015/1008

NOTE: This assumes the data transfer is happening properly.

Changes 2015-10-08 to data flow of STE3

imag40.suth.saao.ac.za

  • One line was changed in this script /usr/local/IMAGE/RunImage:
export IM_DIR=/data/ccd/symlink_imagedir
  • A script runs from /etc/crontab every day at noon; /usr/local/bin/update_imag40_symlink.sh . This redirects the symlink /data/ccd/symlink_imagedir to /data/ccd/image/YYYY/MMDD using the current days date.

This allows data to be written to different directories each day following the standard of other instruments at SAAO.

astro.suth.saao.ac.za

  • A script /usr/local/saao/bin/saaodatagrabv2.sh runs from /etc/crontab every 15 seconds and grabs data from imag40.suth.saao.ac.za using rsync. It then places the data in /data/telescopedata/40in/imag40/YYYY/MMDD .

ltsp.suth.saao.ac.za

This server can access the same data copied by astro.suth.saao.ac.za immediately at a similar location:

/data/40in/imag40/YYYY/MMDD

Troubleshooting

If the observer reports the files are coming through very slowly, there are two things you can do.

1. Reboot image40 if the uptime is great than 30 days. Seems to have a memory leak of some sort - it was nearly unresponsive when I logged on and after a reboot it was fine.

2. Logon to astro.suth.saao.ac.za and check for multiple processes of saaodatagrabv2.sh running. there should only be one which should look something like this:

root     27486  0.0  0.0   1752   520 ?        Ss   19:59   0:00 /bin/sh -c sleep 45 ; for instr in imag40 ; do /usr/local/saao/bin/saaodatagrabv2.sh -i $instr -d today ; done

Kill all of them if there is more than one.