DS9 allows the user to back up the application's current state so it can be restored in a later session. When a backup is invoked, DS9 will save in a backup save set all files needed to restore DS9 to that state, including geometry, data files, colormaps, catalogs, contours, and regions.
A backup save set consists of a text file, called a backup script, and an optional directory, which will contain auxiliary data files needed to restore DS9 to a previous state. The backup file and the auxiliary directory maybe moved across file systems, or even platforms, but must remain together in the same directory.
By default, all data image files are saved within the backup save set. However, the user has the option, via the Preferences, to only save only an absolute pathname to the data file, and not the data file itself. This option will dramatically reduce the size of a backup save set, but will restrict the usage to a particular file system and platform.
Currently, there is no support for masks; External Analysis menus will not be saved; Plot Tool windows will not be saved; IIS frames (IRAF) will not be saved; SAMP and XPA sessions will not be saved.
Image files that have been loaded into DS9 via XPA, SAMP, or from URL will always be saved into the save set but the following load operations are not supported in that circumstance: Open Mosaic IRAF Image, Open Mosaic IRAF Segment, Open Mosaic WCS Image, Open Mosaic WCS Segment, Open Mosaic WFPC2, Open RGB Fits Image, Open RGB Fits Cube, Open RGB Array, Open Multi Ext Data Cube, Open Multi Ext Multiple Frames.
| Command: | backup [filename] |
| Menu: | File - Backup |
| Description: | Creates a DS9 .bck file with a backup of the complete current state of DS9. |
| Command: | restore [filename] |
| Menu: | File - Restore |
| Description: | Restores the complete state of DS9 from a .bck backup file. |
| Command: | - |
| Menu: | Edit - Preferences - General - Always save files during Backup |
| Description: | Ensures that the full image data file is saved. |
| Command: | - |
| Menu: | Edit - Preferences - General - Auto Recovery |
| Description: | Sets an interval for auto backups, default 5 minutes. |
Large Files are files of size more than 4 Gbyte. DS9 is compiled with large file support and recent file systems all support these. DS9 can read files with 'mmap' memory mapping (limited by memory address space) or, slower, by allocating memory.
'ds9 foo.fits' or 'xpaset -p ds9 file foo.fits' uses mmap. 'cat foo.fits | ds9' or 'xpaset -p ds9 fits foo.fits' uses memory allocation.
| Command: | prefs threads [value] |
| Menu: | Edit - Preferences - General - Number of Threads |
| Description: | Controls the max (?) number of processing threads used by DS9. |
| Command: | threads [n] |
| Menu: | - |
| Description: | Set number of process threads to use |
| Command: | sleep [n] |
| Menu: | - |
| Description: | Delay execution for n seconds |
| Command: | update now |
| Menu: | - |
| Description: | Update the image frame. Example: xpaset -p ds9 update now.This is not normally needed unless DS9 is under unusually heavy load. |
| Command: | update [n] [x1 y1 x2 y2] |
| Menu: | - |
| Description: | Update HDU n, image subset x1:x2 y1:y2 |
| Command: | exit |
| Menu: | File - Exit |
| Description: | Closes all DS9 windows and exits. |
| Command: | quit |
| Menu: | File - Exit |
| Description: | Quit is a synonym for exit. |