Data Backup using SCP or FTP
Data transfers using either scp, sftp, and ftp is available to observers. SCP and SFTP are the prefered methods for transfering data because they are more secure. The following rules apply when transfering data:
  • Transfer data during daylight hours. Never transfer data while someone else is observering. Running FTP while you (or someone else) are observing can slow down the network, disk access, cpu speeds, etc. Please be considerate of other observers' needs.
  • Transfer data from the summit. Transfers are faster from the summit. Observers should transfer data while logged into the instrument host computer using the assigned instrument observing account.
  • Remain at Keck until your transfer is complete. If there are problems with the data transfer, staff are not required to address the problem. Observers are encouraged to remain at Keck until the data transfer is complete. Note that there is no incoming FTP access to Keck computers. If you plan to transfer data to an external site via FTP, then you must do so before you leave.
  • Transfer data from Keck to an observer's home institution. Although scp and ftp are supported, most machine's firewall protections do not permit you to copy data when the commands are executed from a host outside of the Keck network. To transfer data, it is recomended that you log into a summit machine and then execute scp or ftp to transfer your data.
  • Your session could be terminated at any time. Staff and the next night's observers require use of the comuters during the day. If for some reason, someone needs to use the computer that is transfering your data, the data transfer could be terminated. In addition, if the data transfer is determined to be causing problems at the summit or at HQ, staff and observers are permitted to terminate your data transfer.

SCP Procedure

Please follow these steps to transfer data using scp:
  1. Use the rlogin command to start a shell on a summit instrument computer. Note that running your scp session from a computer at HQ in Waimea will drastically reduce the transfer efficiency!
  2. cd to your data directory. Use the "cd" command to move to your data directory. "cdata" is an alias to your data directory on an instrument machine. Note that data disks can be accessed using the syntax "/s/sdataXXX".
  3. scp the data (ex: scp *.fits staypuftmarshmellowman@gu.edu:myData/)
  4. Exit the rlogin session by typing "exit" at the command prompt.

SFTP Procedure

Please follow these steps to transfer data using sftp:
  1. Use the rlogin command to start a shell on a summit instrument computer. Note that running your sftp session from a computer at HQ in Waimea will drastically reduce the transfer efficiency!
  2. cd to your data directory. Use the "cd" command to move to your data directory. "cdata" is an alias to your data directory on an instrument machine. Note that data disks can be accessed using the syntax "/s/sdataXXX".
  3. Use the cd to move to the directory where you would like your data stored.
  4. Type
    put *.fits
    to transfer all of the FITS images in the directory.
  5. When the transfer has completed, you may use the command
    lcd directory
    to move to another directory on the Keck machine, and use put again to copy the data.
  6. When done transferring all files, type quit to end your FTP session.
  7. scp the data (ex: scp *.fits staypuftmarshmellowman@gu.edu:myData/)
  8. Exit the rlogin session by typing "exit" at the command prompt.

FTP Procedure

  1. Use the rlogin command to start a shell on a summit computer. Running your FTP session from a computer at HQ in Waimea will drastically reduce the transfer efficiency!
  2. cd to your data directory. Use the cd command to move to your data directory. "cdata" is an alias to your data directory on an instrument machine. Note that data disks can be accessed using the syntax /s/sdataXXX.
  3. Run the ftp command to start an FTP session.
  4. Use the command
    open my_home_site
    to open an FTP connection to your home site. Provide the proper account name and password to log in.
  5. Use the cd to move to the directory where you would like your data stored.
  6. Issue the command binary to set binary transfer mode.
  7. Issue the command prompt to turn off verification of each file transfer.
  8. Type
    put *.fits
    to transfer all of the FITS images in the directory.
  9. When the transfer has completed, you may use the command
    lcd directory
    to move to another directory on the Keck machine, and use put again to copy the data.
  10. When done transferring all files, type quit to end your FTP session.

Using FTP to transfer to a laptop with no FTP server

  • As above, if you are using ftp or sftp to transfer to a host with an ftp server, initiate your transfer from the instrument host and use 'put.' However, if you are transferring to a laptop with no ftp server, then you can use the laptop's ftp client and connect to a summit ftp server and use 'get'. However, note the following:
    With the advent of MaxOS 10.5, a compatibility issue has surfaced between that system's ftp client and the (much older) ftp server running on most of our summit instrument computers. So, for example, using a 10.5 Mac to make an ftp connection directly to the NIRSPEC host, waimea, to transfer data from /sdata603, will result in the first file transferring very slowly and then the transfer stops altogether. To work around this problem, make an ftp connection to svncserver2 (svncserver1 for a K1 instrument like LRIS) and then use the "/s" method to access the data disk (e.g., for the NIRSPEC example, cd /s/sdata603).

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SCP procedure
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