So I work in a lab which has a Linux machine (22.04 LTS jammy) as the main computer to manage a file server. The Linux machine has a network interface that allows multiple computers in the lab to connect to the file server (via etc/network/interface) as hosts and another for two Synology NAS drives that act as the file servers/shared folders (these are in etc/hosts as well). These drives (DS1821+ and DS1813+) are mounted to the Linux machine (via etc/fstab).
Now, here's the problem I have, when I try to shutdown one of the drives (via Synology's DSM), PCs in the lab and even the Linux machine becomes unresponsive when running applications. Specifically file explorer, although one PC shutdown entirely. I spoke with Synology and upon checking the drives, nothing should cause this to happen. I unmounted one drive from the file explorer via mount network drive in Windows on one of the PCs to see if the problem persisted, but to no avail. I've since checked the network configurations (per the above paragraph) and the machine acts as a router and it's connected to an unmanaged switch (NetGear GS105), or the drives are. Nothing seems too uncanny, although I am new to networking and Linux administration (following the Ward's "How Linux Works" (2021), Nemeth et al's "UNIX and Linux System Administration Handbook" (2017), and the Ubuntu help and documentation site to understand the system). Below are the files I've mentioned so far. I've never modified them, they're as I came across them following the previous person I took over for.
My thinking is that, given the configuration, I have to unmount the drives before shutting them down to allow the hosts on the network to function properly. The idea seems counter-intuitive to me, but it's the only solution I can imagine for the problem given the configuration. What do you all think? If this is the proper solution, does anyone have any advice on safely unmounting the drive?
I've renamed/coded the names of files and ip addresses, but they're consistent across the files below. Also, these are snippets of the files, not the whole files.
etc/fstab
#NAS mount
Server:/volume1/share /net/sharedfolder nfs rw,intr 0 0
ip1:/volume1/share2 /net/sharedfolder2 nfs rw,intr,vers=4,addr=ip1,clientaddr=ip2 0 0
etc/network/interfaces
auto eth0
#iface eth0 inet dhcp
iface eth0 inet static
metric 0
address ip3
netmask ip2
gateway ip4
dns-nameservers 8.8.8.8
# dns-search dnsname
auto eth3
#iface eth3 inet dhcp
iface eth3 inet static
metric 1
address ip2
network ip5
netmask ip6
gateway ip7
etc/hosts
ip8 Server
ip7 hostname_switch
ip1 hostname
