File Compress
 

I've a file which is of size 25GB,but the free space in that mount point is 11GB,can i compress that file without any problem,by just having free space of 11GB?The platform is AIX.

Please someone give me the answer as soon as possible.

It depends. If the file will compress to less than 11 GB the answer is yes. However 11 GB for a 25 GB requires better than 2 to 1 compression (2 to 1 would require 12.5 GB). If the files has a lot of blank space and is flat ascii then it will give you very high compression. If however it is densely packed data you may not even get 2 to 1 compression. In some odd cases files get larger when compressed (for example a tar file that itself contained several compressed files would grow if you tried to compress it).

Trying the compression shouldn't hurt anything (except filling the filesystem) as it doesn't impact the original file until after the compression is complete. I'd open two windows. Start the compress in one and watch the space utilization in the other. If it gets to 99% without completing the compression kill the compress job to prevent it going to 100%. At the kill it will remove what it has done so far and return you to the 11 GB free and leaving your original 25 GB file as is.

If you have another filesystem with more space you can try moving the file there. Then do the compress. The move the compressed file back to the original filesystem (which should have 36 GB free after your original move).

If you were to get the 25gigs to fit to 11, then once the compression is done, good luck finding the space to uncompress in a month or so when you've started eating up the 25 gigs.