Mac turns itself off randomly while using Jellyfin

[Kal-El]

So I have large external drive on which I store my digital media and host my Jellyfin server, and lately the strangest thing has been happening. My Mac (desktop, running High Sierra) random turns itself off after 30-60min, but only when I my external drive is plugged in. If I'm not doing anything with the drive and Jellyfin it won't shut itself down. I checked my settings and the computer isn't set to power off after a set time or time allotment. I thought maybe the USB port in the front of the desktop was too weak and may be the culprit so I started using one of the USB ports in the back of the desktop tower, but it didn't solve my problem.

What is causing this and what can I do to fix it? Thanks.

[october262]

So I have large external drive on which I store my digital media and host my Jellyfin server, and lately the strangest thing has been happening. My Mac (desktop, running High Sierra) random turns itself off after 30-60min, but only when I my external drive is plugged in. If I'm not doing anything with the drive and Jellyfin it won't shut itself down. I checked my settings and the computer isn't set to power off after a set time or time allotment. I thought maybe the USB port in the front of the desktop was too weak and may be the culprit so I started using one of the USB ports in the back of the desktop tower, but it didn't solve my problem.

What is causing this and what can I do to fix it? Thanks.

does your external drive have something for a external power supply ??

[Kal-El]

So I have large external drive on which I store my digital media and host my Jellyfin server, and lately the strangest thing has been happening. My Mac (desktop, running High Sierra) random turns itself off after 30-60min, but only when I my external drive is plugged in. If I'm not doing anything with the drive and Jellyfin it won't shut itself down. I checked my settings and the computer isn't set to power off after a set time or time allotment. I thought maybe the USB port in the front of the desktop was too weak and may be the culprit so I started using one of the USB ports in the back of the desktop tower, but it didn't solve my problem.

What is causing this and what can I do to fix it? Thanks.

does your external drive have something for a external power supply ??

Yes, it has a standard power cord that plugs into my battery backup.

[johns0]

Sounds like your battery backup isn't working as good as before and your system runs out of power.

[october262]

So I have large external drive on which I store my digital media and host my Jellyfin server, and lately the strangest thing has been happening. My Mac (desktop, running High Sierra) random turns itself off after 30-60min, but only when I my external drive is plugged in. If I'm not doing anything with the drive and Jellyfin it won't shut itself down. I checked my settings and the computer isn't set to power off after a set time or time allotment. I thought maybe the USB port in the front of the desktop was too weak and may be the culprit so I started using one of the USB ports in the back of the desktop tower, but it didn't solve my problem.

What is causing this and what can I do to fix it? Thanks.

does your external drive have something for a external power supply ??

Yes, it has a standard power cord that plugs into my battery backup.

is the external drive a SSD or a spinner HDD ??
is the external drive in an enclosure ?