Hot answers tagged mount
You probably just want to use XFS. It's quite capable of what you're asking for, and does the job. There's no reason to complicate this with lesser-used filesystems, which can come with other tradeoffs. Please see: How does the number of subdirectories impact drive read / write performance on Linux? and The impact of a high directory-to-file ratio on XFS ...
What you want do do can be achieved precisely with overlayfs. With it you can take your /full dir and another /notfull dir and mount them at /third-dir. Reads will seek through the /notfull into the /full and writes will go to a third dir. Have a look at the docs, remount the full dir away from the target name and then use overlayfs to recreate the ...
You won't be able to expand the space by mounting them both on /folder if that's what you want. If you want to create another directory like /folder/newshare like you said, you should be able to mount another NFS share there to make it seem like there's more space under /folder. I just confirmed that I could create a mount point for a NFS share inside ...
If it is read-only, why to not use a ISO file? You can use genisoimage or mkisofs. If you want to compress the whole thing, you can also use squashfs, another read-only filesystem with very high compression ratio.
Seeing the number of small files, I would consider using SquashFS. Especially if you have powerful enough CPU (meaning no Pentium III, or 1GHz ARM). Depending on the type of data stored, SquashFS can greatly reduce its size and thus the I/O when reading it. Only downside is CPU usage on read. On the other hand, any modern CPU can decompress at speeds far ...
I am not sure if this fits your purpose, but have you considered tar to combine multiple files? That might decrease the pressure and space requirements on the filesystem, and your database application can read data for a specific file with one of the many tar libraries around. Depending on your access pattern this might even increase the performance.
Only top voted, non community-wiki answers of a minimum length are eligible