Can I retrieve files from hard drive in case of nextcloud server crash? Is it possible to add a disc already with files so that later not to upload to the Internet
I use nextcloud with VMware
Yes you can put it on an extra drive. Hopefully the disk doesn’t crash when the server crashes, so please do make backups. If you have a full backup (data + database +config file), you can just restore your server. If you have just the data, the clients want to resync everything, they can’t compared based on the file size and checksums.