Das klappt nicht:
blkid /dev/sda1
/dev/sda1: UUID="647c07e2-0500-49b7-8b1d-f297422a21b9" TYPE="ext4" PARTUUID="cce9cd82-01"
UUID=647c07e2-0500-49b7-8b1d-f297422a21b9 /mnt/sda1 ext4 defaults 0 0
UUID=647c07e2-0500-49b7-8b1d-f297422a21b9 /data mergerfs defaults,category.create=mfs,direct_io,use_ino 0 0
MLD-ClientSP> mount
/dev/mmcblk0p2 on / type btrfs (rw,relatime,ssd,noacl,space_cache,subvolid=259,subvol=/@root)
proc on /proc type proc (rw,relatime)
sys on /sys type sysfs (rw,relatime)
tmp on /tmp type tmpfs (rw,relatime)
run on /run type tmpfs (rw,relatime)
dev on /dev type devtmpfs (rw,relatime,size=374004k,nr_inodes=93501,mode=755)
devpts on /dev/pts type devpts (rw,relatime,gid=5,mode=620,ptmxmode=000)
/dev/mmcblk0p3 on /mnt/mmcblk0p3 type xfs (rw,relatime,attr2,inode64,noquota)
/dev/mmcblk0p3 on /var/cache type xfs (rw,relatime,attr2,inode64,noquota)
/dev/mmcblk0p1 on /boot type vfat (rw,relatime,fmask=0002,dmask=0002,allow_utime=0020,codepage=437,iocharset=ascii,shortname=mixed,errors=remount-ro)
USB-Platte ist nicht da. Komisches Ding das...