Is it possible to install Nextcloud on RAID1, like we can do on TrueNAS, using 2 ssd ?
Thanx in advance.
Sure, but that depends on the operating system used and how this operating system was installed.
Nextcloud is not an appliance like TrueNAS, Nextcloud is an application, that you usually install on top of an existing operating system. If this operating system is running on disks, wich are configured to run in a RAID1 array, then you could say: “Nextcloud is running on RAID1”.