I encounter a performance problem with two HDDs. One is fast but mounted remotely through NFS, the other is local (ext4) but slow.
No, exchanging the two drives is not an option, because it would make the installation on the other system suffer from it.
I have the subjective impression that most of the performance loss is happening during the writing of cached data (in both cases: local and remote).
An other empirical evidence is that
sync takes always less that a second, even after lots of writing. Again, for me it means: the write cache is too small, or is used too little, or similar.
The question is: can I improve performance with some mount options?
I have found in mount's man page some option which might have to do with performance:
delalloc. But I can't guess what's the default, what they do, ...
Additional question: Is there a chance of improving performance by reformatting an ext4 partition with different options?