问题
I am trying to create a patch using two large size folders (~7GB).
Here is how I'm doing it :
$ diff -Naurbw . ../other-folder > file.patch
But maybe due to file sizes, patch is not getting created and giving an error:
diff: memory exhausted
I tried making space more than 15 GB but still the issue persists. Could someone help me out with the flags that I should use?
回答1:
Recently I came across this too when I needed to diff two large files (>5Gb each).
I tried to use 'diff' with different options, but even the --speed-large-files had no effect. Other methods like splitting the files into smaller ones, using xdelta or sorting the files as per this suggestion didn't help either. I even got my hands around a very powerful VM (> 72Gb RAM), but still got this memory exhausted error.
I finally got to work by adding the following parameter to sysctl.conf (sudo vim /etc/sysctl.conf):
vm.overcommit_memory=1
vm.overcommit_memory has three values (0,1,2) and sets the kernel virtual memory accounting mode. From the proc(5) man page:
0: heuristic overcommit (this is the default)
1: always overcommit, never check
2: always check, never overcommit
To make sure that the parameter is indeed applied you can run
sudo sysctl -p
Don't forget to change this parameter back when you finish!
回答2:
bsdiff is slow & requires large memory, xdelta is create large delta for large files.
Try HDiffPatch for large files: https://github.com/sisong/HDiffPatch
- support diff between large binary files or directories;
- can run on: Windows, macos, Linux, Android
- diff & patch both support run with limit memory;
Usage example:
- Creating a patch:
hdiffz -s-256 [-c-lzma2] old_path new_path out_delta_file - Applying a patch:
hpatchz old_path delta_file out_new_path
回答3:
Try sdiff It's pre-built tool in linux Distributions.
sdiff a.txt b.txt --output=c.txt
will show the files to be Modified.
This worked perfectely for me .............
来源：https://stackoverflow.com/questions/15264062/memory-exhausted-for-large-files-using-diff