GISAXS @ D-line: Data
Q: Where
are my data ?
Each D-line user gets a user directory assigned on /home/specuser/USER, where USER corresponds to the name
of the PI of the experiment. USER has the following default
subdirectories:
The data directory
contains the SPEC output
files. These are all line-up and reflectivity scans, all appended to
one file FILENAME, the
name of which is declared in the newfile
command. This file contains other important information, such as
all motor positions at the beginning of each scan or CCD exposure
(which corresponds to a tseries scan
in SPEC) and the count
rates of all monitor detectors along the beamline. The contents, i.e.
the important header lines, of such a log file can be listed using the
D1 scan command. At the
LINUX prompt, type:
scan
FILENAME
which generates a list of information on the screen, or
scan
FILENAME > FILENAME.LOG
which writes the file information to a file FILENAME.LOG which can
complement your logbook notes. scan
is a awk script that will
run on UNIX and LINUX computers.
The corr and dark directories contain all
your images, the automatically corrected ones in corr, the dark images in dark.
The /home/specuser/images
directory contains all raw data files that
the CCD
collects. At the end of a user experiment
~/images should be copied
to USER/raw, if users
would like to keep the raw images:
- cd ~/images
- mv *.tif ~/[user]/raw
Otherwise, raw images will be removed to make space for the next user
group.
Q: How do I
take my data home ?
After several years of struggling with this problem, the following
procedure has proven to be solid:
- go to the CHESS User Computer Room and copy your file to one of
the computers there (Windows XP, Mac OS-X, Linux) using ftp or ssh.
- the most suitable storage device I have seen is a hard disk.
- You can either copy to the hard disk of you Lap Top (there are
plenty of high-speed ethernet connections in the Computer Room)
- or use an external hard disk. External USB and Firewire ports are provided
for each of the User Computers, and data can be copied directly to the
external drive (i.e. without buffering them on the User Computer).
- because of the large amount of data produced by the area
detector, I discourage the use of the CD or DVD burners.
- DO NOT try to hook up
external storage devices to the beamline computer - it is too easy to
crash LINUX this way and
make a huge mess.
Q: How do I
set up a lap top at D-line ?
The easiest and most reliable way is to connect the lap top to an
ethernet connector (there are 2 user ports at the desk top and 1 at the
prep table) and choose
"find address automatically". No special password is required. Please
do not hook up lap tops to the switch connecting the beaamline computer
and the CCD computer.
The Wilson Lab wireless network requires a password. Please contact the
CHESS Computing Group for assistance. There may be interference with
the metal hutch walls, so the beamline control area is not ideal for
wireless networks.
for
internal use: beamline computer hard disk back-up
The present 120GB hard disk at D-line is relatively limited in its
capacity for high-throuput GISAXS.
Hence when the user partition of the disk reaches 95%, I have to move
files to the back-up server.
In the following a set of the relevant commands.
- start differential back-up:
- > cd /usr/local/backup/
- > ./backup-script &
- the "&" let's backup-script run in the background
- always use "&" when logged in via modem
- > cat rsync.log
- this allows to watch the backup as it progresses
- note: computer performance will slow down during back-up
- check log and error log to verify successful transfer, and
create a copy of the log
- > cat rsync.log
- > cat rsync_error.log
- > cp rsync.log May12-05.log
- list files and directories on back-up server
- > rsync
rsync://offsite.chess.cornell.edu/CHESS/specuser/d1/chess/cornell.edu/specuser/
- > rsync
rsync://offsite.chess.cornell.edu/CHESS/specuser/d1/chess/cornell.edu/specuser/[subdirectory]/
- note: the final slash "/" is important, so that the content of
the directory will be listed!
- copy files and directories from back-up server
- copy file:
- > rsync
rsync://offsite.chess.cornell.edu/CHESS/specuser/d1/chess/cornell.edu/specuser/[sub]/[file]
[sub]/.
- note: wildcards are allowed, but may produce strange
behaviour,
if directory name is part of the set
- copy directory:
- > rsync
rsync://offsite.chess.cornell.edu/CHESS/specuser/d1/chess/cornell.edu/specuser/[sub]/
[sub]/
- note: copies the contents of the subdirectory to the target
subdirectory
- > rsync
rsync://offsite.chess.cornell.edu/CHESS/specuser/d1/chess/cornell.edu/specuser/[sub]
[sub]
- note: copies the subdirectory