on Yun Rev2 the file system expanded on SD switches to 'ro'

Hello everybody. I installed a Yun Rev2 board, I inserted an SD card and ran the file system expand sketch.
the file system I got at the end is, from the /etc/mtab file

/dev/root /rom squashfs ro,relatime 0 0
proc /proc proc rw,nosuid,nodev,noexec,noatime 0 0
sysfs /sys sysfs rw,nosuid,nodev,noexec,noatime 0 0
tmpfs /tmp tmpfs rw,nosuid,nodev,noatime 0 0
/dev/sda2 /overlay ext4 rw,sync,noatime,nodiratime,data=ordered 0 0
overlayfs:/overlay / overlay rw,noatime,lowerdir=/,upperdir=/overlay/upper,workdir=/overlay/work 0 0
tmpfs /dev tmpfs rw,nosuid,relatime,size=512k,mode=755 0 0
devpts /dev/pts devpts rw,nosuid,noexec,relatime,mode=600,ptmxmode=000 0 0
/dev/sda2 /mnt/sda2 ext4 rw,sync,relatime,data=ordered 0 0
debugfs /sys/kernel/debug debugfs rw,noatime 0 0
/dev/mtdblock5 /mnt/mtdblock5 jffs2 rw,relatime 0 0
mountd(pid1404) /tmp/run/blockd autofs rw,relatime,fd=7,pgrp=1,timeout=30,minproto=5,maxproto=5,indirect 0 0
/dev/sda1 /mnt/sda1 vfat rw,relatime,fmask=0000,dmask=0000,allow_utime=0022,codepage=437,iocharset=iso8859-1,shortname=mixed,errors=remount-ro 0 0

It can be seen that sda1 has the option errors=remount-ro (I do not know if it is set and hidden somewhere or it is a default not overwritten). As a result if I get a file system error the file system itself is remounted 'ro' and is unusable. I can recover only with a reboot.

the mtab file shows

/dev/root /rom squashfs ro,relatime 0 0
proc /proc proc rw,nosuid,nodev,noexec,noatime 0 0
sysfs /sys sysfs rw,nosuid,nodev,noexec,noatime 0 0
tmpfs /tmp tmpfs rw,nosuid,nodev,noatime 0 0
/dev/sda2 /overlay ext4 rw,sync,noatime,nodiratime,data=ordered 0 0
overlayfs:/overlay / overlay rw,noatime,lowerdir=/,upperdir=/overlay/upper,workdir=/overlay/work 0 0
tmpfs /dev tmpfs rw,nosuid,relatime,size=512k,mode=755 0 0
devpts /dev/pts devpts rw,nosuid,noexec,relatime,mode=600,ptmxmode=000 0 0
/dev/sda2 /mnt/sda2 ext4 rw,sync,relatime,data=ordered 0 0
debugfs /sys/kernel/debug debugfs rw,noatime 0 0
/dev/mtdblock5 /mnt/mtdblock5 jffs2 rw,relatime 0 0
mountd(pid1404) /tmp/run/blockd autofs rw,relatime,fd=7,pgrp=1,timeout=30,minproto=5,maxproto=5,indirect 0 0
/dev/sda1 /mnt/sda1 vfat ro,relatime,fmask=0000,dmask=0000,allow_utime=0022,codepage=437,iocharset=iso8859-1,shortname=mixed,errors=remount-ro 0 0

Is it possible to have a file system without this option ?? Also a not critical error not checked blocks the sketch. Normally on other Linux systems I was used to have an 'fstab' file where the file system parameters were set and could be edited, but I am not able to find it in OpenWrt.

Thanks for any help.