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Here is a list of gotchas or concerns that I stumbled into during this these project investigations.
- Tilde (~) does not work. Remember that LD2.0 machines have their own user databases which are not the same as the SLAC site unix user database. If you are accustomed to typing "$ ls ~lsstprod/workflows", that will no longer function. It is not clear how to implement a good, reliable work-around.
Absolute NFS file paths will be different. Using sshfs means every remote file system must have a local mount point. On central SLAC machines, "/nfs" works. However, sshfs documentation recommends that mount points be r/w by the user and, usually, /nfs is not such a candidate. So any scripts or aliases that use the "/nfs" path must be changed. [AFS/YFS is different in that if you elect to have the client installed, the absolute paths will look identical with that on a public SLAC machine.]
** WORKAROUND: On a single-user workstation in the SLAC network, the following example shows how to allow a customary absolute NFS path using a symbolic link:Code Block sudo ln -s /nfs /home/dragon/nfs mkdir -p /home/dragon/nfs/farm/g/lsst sshfs dragon@rhel6-64:/nfs/farm/g/lsst /nfs/farm/g/lsst
Access to AFS home directories can proceed either via an absolute path, e.g., `/afs/slac/u/...` or one can create a symbolic link to recover the familiar `/u/ec/dragon/...` path.
Code Block sudo ln -s /afs/slac.stanford.edu/u /u
Lots of SLAC-written and SLAC-specific commands are no longer available locally, e.g., everything in /usr/local/bin
** WORKAROUND: Create an alias in your .bashrc to prefix your favorite SLAC command(s) with "ssh rhel6-64 ", e.g.Code Block alias person='ssh rhel6-64 person '
- Printing is currently possible via the unix print server, but I've heard rumors that this service might be deprecated and replaced with a Windows-based system. Also, the current print config in use on comet2 is very rudimentary and needs further thought. It does not, for example, know about printer-specific functions & capabilities, such as faxing, duplex printing, oddball paper sizes, etc.
** FIX: The "BrightQ" print drivers for Canon printers are straight-forward to install, interface seamlessly with CUPS, and offer all the features of my printer (a Canon C5255). There is a bit of a rigamorole involved (one must "register" twice, once for download and again for installation), but in the end it worked well. Get the drivers here: https://www.codehost.com/canon/ - Many users will need a moderately-to-highly customized application repertoire to work well for them. The application list above is acceptable for my (TG) work needs. But there are items that even I need only rarely and it is not clear it is better to seek them out and install locally, or to simply log into a public login machine to use. Here I am thinking of database tools, advanced development tools, TeX (and friends), more sophisticated printing capabilities, etc.
- While for may activities it is desirable to work locally, one will still need to log onto a public SLAC login machine (think licensed software, certain computing resource management functions, dealing with PPI, etc.) There are certain files and directories that I would like synchronized between the desktop machine and my SLAC environment (such as ssh keys, personal logbook, app configurations). Possibly a trscron job would do the trick, but then which copy becomes the master? I would like a smart synchronizer that allows either environment to make changes that will then be reflected in the other environment.
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