New to Linux and running Mint v21.

I have created RAID1 device, using mdadm, on a 5 Bay USB Hard Drive Enclosure.
I do not want fstab to mount this RAID device at boot as the USB Hard Drive Enclosure is not always on.
I understand that the fstab "defaults" option is equivalent to rw, suid, dev, exec, auto, nouser, async, which includes auto mounting at boot. Can I use both defaults and noauto (defaults,noauto) together in the same fstab device entry in order for the RAID device not to be amounted at boot or would it better to explicitly list all of the options (rw,suid,dev,exec,noauto,nouser,async)?

I don't think you can defaults because that is auto. Just specify all the options you want and noauto.

I have often customized my fstab, but I've never tried this combination. I would think that using "defaults" and then specifying something that is not a default would not be an optimal action, because it sets up an internal contradiction in fstab.

If I'm wrong, I trust someone more knowledgeable than I will set me straight.

Typically the last option wins so with defaults,noauto the noauto should override auto. I probably would go with specifying all the defaults individually.

1 members found this post helpful.

Thanks, michaelk. I learned something new because of you.

AIUI, defaults is purely a placeholder for the options column. It's inert used in conjunction with any specific options. Only using noauto means use all the other defaults, but mounting requires an explicit mount command. Mount -a fails, and automatic mount at boot is not attempted. IIRC, none of my current fstabs include the string defaults anywhere.

The "defaults" is a filler word and does nothing.
It must be there if there is no option, otherwise the column would be empty and the format would be wrong.

Thanks for all the insight into fstab options. Very helpful and just what I needed.