Caching (GWC) Imagery

Issues I've run into while caching imagery on Geoserver/GWC

• Out of Memory Errors (java.lang.OutOfMemoryError: PermGen space): Solved this (as suggested here) by adding -Xms48m -Xmx256M -XX:MaxPermSize=128m to Geoserver's startup.bat/startup.sh on the line that starts the JVM (for me it was line 120)
• also found a post suggesting adding UseCompressedOops fixed some issues with caching imagery ... from

"%RUN_JAVA%" -DGEOSERVER_DATA_DIR="%GEOSERVER_DATA_DIR%" -Djava.awt.headless=true -DSTOP.PORT=8079 -DSTOP.KEY=geoserver -jar start.jar

to

"%RUN_JAVA%" -XX:+UseConcMarkSweepGC -XX:+CMSClassUnloadingEnabled -XX:+CMSClassUnloadingEnabled -Xms48m -Xmx512M -XX:MaxPermSize=256m -XX:+UseCompressedOops -DGEOSERVER_DATA_DIR="%GEOSERVER_DATA_DIR%" -Djava.awt.headless=true -DSTOP.PORT=8079 -DSTOP.KEY=geoserver -jar start.jar

• ERROR [seed.MTSeeder] - Problem communicating with GeoServer : was getting this error because a DB parameter had recently changed (DB name)
• Error ... Could not list layers for this store, an error occurred retrieving them ... then something about null argument ... this was also fixed with these memory options
• I also found it necessary to scale down my imagery using the outsize parameter  with gdal translate

gdal_translate -of GTiff -co "TILED=YES" -outsize 50% 50% input-file.tif output-file.tif

• I think I may also have been having trouble not adding a world file (possibly prj) which I then created with ArcGIS (not sure how to do that with GDAL, since that saves the geographic info directly to the TIFF)