The original plan for ROSA data transfer was to use LTO3 tapes, but that was made obsolete by the rapid advance in hard drive capacities, so the default now is to use hard drives connected via the fast eSATA interface. At the moment there are eSATA facilities on das1 and das2 only. This is because the normal mode of operations for ROSA has das1 and das2 running at the highest frame rates, typically generating 10x the amount of data that das3-das6 do. We therefore suggest that observers bring a number of drives with eSATA capabilities, plug these into das1/2 and then perform all data copies from those machines. Note that due to the vintage of the hardware only disks up to 2TB capacity are supported.
All drives being used with ROSA should be configured with a single partition, formatted as Linux ext2 or ext3 - this can be done on any Linux system, or on the ROSA machines if needed. Instructions are available below.
Given the number of variables involved - which cameras are in use, and at what cadence, etc - it is impossible to give a definitive guide on how to transfer data, or indeed script it in any meaningful manner. Different observers will have different needs and are likely the best judges of their own interests. So below we provide a general guide on what to do - this should be trivial for anyone with a basic knowledge of using Unix on the command line. The notes assume that you are logged onto das1 or das2 using the credentials given in the User Guide, and that your drive is partitioned and formatted as outlined below.
You may wish to use the du and df commands to check how much disk space is needed and free respectively:
The ROSA computers run RedHat Enterprise Linux 4, and only understand the Linux ext2 or ext3 formats. Third party software is available to permit such disks to be read under Mac OS X and Windows, or you can mount them using a virtual machine. In case you need to format disks while at the telescope, here is how you can do so from the ROSA computers. This is a standard Linux partition and format routine and can be done on any modern Linux system - ask your systems manager if in doubt. Note once more that ROSA only supports disks of up to 2TB.
You should now be able to mount the formatted disk and check the available capacity by typing:
Finally you may unmount the drive (if needed) by typing umount /mnt at which point the drive may be unplugged.