I do just that. But calibre doesn't support networked filesystems. But it might work, depending on what networked filesystem you use. Test carefully, have good backups and don't complain if/when your library becomes corrupt.
I use Ubuntu Linux and a Synology NAS, shared using NFS. I think SMB and CIFS is more trouble, that's why I use NFS... Also case sensitivity differences between operating systems and file systems may cause problems. For instance if you have a Windows computer and a Linux NAS. Test carefully...
I have / mounted on the SSD, and /home on a mechanical hard drive. And /home/adoby/nas is the NAS, of course.
I have metadata.db in /opt/speedup/adoby and on the NAS I have the calibre library. I replaced the original metadata.db with a symlink to the real metadata.db on the SSD.
I also have various disk caches in /opt/speedup/adoby, instead of in /home/adoby. Also using symlinks. And use part of the RAM as /temp.
Works fine.
There also is an environment variable you can use for this purpose.
CALIBRE_OVERRIDE_DATABASE_PATH
http://manual.calibre-ebook.com/cust...ment-variables
I have two calibre libraries, fiction and nonfiction, so the symbolic link works best for me. Makes it easy to switch libraries.
See also:
https://www.mobileread.com/forums/sho....php?p=2244745