WTF is a scratch disk?

[Melinda]

My computer is royally screwed, it wont let me burn a CD and when I try to open photoshop it wont let me because it says all the scratch disks are full...What the heck is a scratch disk and why would my computer be doing this??? Help! I have alot riding on my computer right now!

[Dirty_SOHC]

http://www.adobe.com/support/techdocs/c1c6.htm

Error "Scratch Disk is Full" When Editing a File in Photoshop

Issue
When you edit a file in Adobe Photoshop for Windows, Photoshop returns the error, "Scratch disk is full."


Solutions

Do one or more of the following:


Solution 1
Make sure that the image has an appropriate resolution setting:
1. Determine the resolution required by the destination device (e.g., monitor, printer). For more information, see "About image size and resolution" on pages 92-95 of the Adobe Photoshop 6.0 User Guide or pages 54-57 of the Adobe Photoshop 7.0 User Guide.


Note: The Resolution setting in the Image Size or New dialog box is in pixels per inch (ppi), not dots per inch (dpi). Don't use the maximum dpi of your printer for the ppi of your image. Even a high-end imagesetter that can print at 1200 dpi or higher requires only between 200 and 300 ppi, not 600 ppi.


2. Choose Image > Image Size.
3. Change the Resolution setting to an appropriate ppi for the destination device, and click OK.


Note: If you later increase the resolution, the image may appear blurry or out of focus. For more information, see "About Resampling" on page 96 of the Adobe Photoshop 6.0 User Guide or pages 57-58 of the Adobe Photoshop 7.0 User Guide, or search for "resampling" in the online help. To avoid deterioration in image quality, always resample in a copy of the original image.


4. Choose File > Save As, and save the image with a new filename.
5. Close and reopen the new image.


Solution 2
Specify one or more hard drive partitions that have enough free space--approximately three to five times the file size of the largest image and at least ten times the size of the largest bitmap-mode image--as scratch disks. Don't specify a network drive or removable media such as a Zip or JAZ drive. Photoshop 6.x can create 200 GB of scratch disk files on up to four hard disk partitions; Photoshop 7.0 can create an unlimited number of scratch disk files, limited only by hard disk space.


To set the Scratch Disk preference:
1. Choose Edit > Preferences > Plug-Ins & Scratch Disks.
2. Choose the drive that has the most free space from the First pop-up menu.
3. Choose a second, third, or fourth drive, if available, from the Second, Third, or Fourth pop-up menus.
4. Click OK.
5. Restart Photoshop.


Solution 3
Optimize and defragment hard disks:
-- In Windows XP or 2000, use the Disk Cleanup and Disk Defragmenter utilities by choosing Start > Programs > Accessories > System Tools.
-- In Windows Me or 98, use the ScanDisk and Disk Defragmenting utilities by choosing Start > Programs > Accessories > System Tools.
-- In Windows NT 4.0, scan hard disks for errors by typing CHKDSK/f at the Command Prompt. Then, defragment hard disks by using a Windows NT 4.0-compatible third-party utility.


Solution 4
Increase the amount of virtual memory available to Windows. For instructions, see Additional Information.


Solution 5
Adjust the percentage of memory used by Photoshop:
1. Choose File > Preferences > Memory & Image Cache.
2. In the Physical Memory Usage section, change the Used By Photoshop setting to 75%, and then click OK.
3. Restart Photoshop.


Solution 6
Re-create Photoshop's general preferences file by exiting from Photoshop, renaming the file (e.g., to Filename.old), and then restarting Photoshop:


Note: If you delete the general preferences file instead of renaming it, custom preferences settings will be lost. For more information, see document 312917, "Photoshop and ImageReady Preferences Files."


First, if Windows doesn't show filename extensions, enable it to do so:
1. In Windows Explorer, choose View > Options (Windows NT), Tools > Folder Options (Windows XP or 2000), or View > Folder Options (Windows Me or 98), and then click the View tab.
2. Select Show All Files in the Hidden Files section or folder, deselect the option labeled "Hide File Extensions for Known Files" (Windows 98 or ** NT 4.0) or "Hide File Extensions for Known File Types (Windows XP, 2000, or Me), and then click OK.


Then, rename the appropriate file:


Mac OS
-- In Photoshop 7.0, the Adobe Photoshop 7.0 Prefs file is in the Users: [user profile]: Library: Preferences: Adobe Photoshop 7.0 Settings folder (OS X) or in the System Folder: Preferences: Adobe Photoshop 7.0 Settings folder (OS 9.x).


-- In Photoshop 6.x, the Adobe Photoshop 6.0 Prefs file is in the System Folder: Preferences: Adobe Photoshop 6.0 Settings folder.


Windows

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[Khyron]

Originally posted by Melinda
My computer is royally screwed, it wont let me burn a CD and when I try to open photoshop it wont let me because it says all the scratch disks are full...What the heck is a scratch disk and why would my computer be doing this??? Help! I have alot riding on my computer right now!

I'm just gonna say, your harddrive is probably full. You should NEVER be less than 80% full or you'll hurt performance. Go delete some stuff and try again.

Khyron

[Davetronz]

Yea basically what Rollie said Mel.
Look at that nice boyfriend finding ALL that information for you.

[Superesc]

set your scratch disc (if you haven't and if you have more drives/volumes, set them). Also PURGE often (PS: Edit -> PURGE -> ALL) when working. (if your scratch disc is small.)