Это всего лишь опция для mount, указывающая что делать, если обнаружены ошибки в файловой системе.
$ man mount
[...]
Mount options for ext2
[...]
errors=continue / errors=remount-ro / errors=panic
Define the behaviour when an error is encountered. (Either ignore errors and just mark the file system
erroneous and continue, or remount the file system read-only, or panic and halt the system.) The default
is set in the filesystem superblock, and can be changed using tune2fs(

.
[...]
Mount options for ext4
The `ext4' is an an advanced level of the ext3 filesystem which incorporates scalability and reliability enhance‐
ments for supporting large filesystem.
The options journal_dev, noload, data, commit, orlov, oldalloc, [no]user_xattr [no]acl, bsddf, minixdf, debug,
errors, data_err, grpid, bsdgroups, nogrpid sysvgroups, resgid, resuid, sb, quota, noquota, grpquota, usrquota and
[no]bh are backwardly compatible with ext3 or ext2.