adb push not working on /system, read only I can do adb push to /sdcard/ location but not /system on my android device.

sudo adb push lib/audio.primary.gmin.so system/lib/hw/
failed to copy 'lib/audio.primary.gmin.so' to 'system/lib/hw/audio.primary.gmin.so': Read-only file system


I tried some suggestions online 

user$ adb remount
dm_verity is enabled on the system partition.
Use "adb disable-verity" to disable verity.
If you do not, remount may succeed, however, you will still not be able to write to these volumes.
remount of /system failed: Read-only file system
remount failed
user$ adb disable-verity
Verity already disabled on /system


Even after this, remount fails

user$ adb remount
dm_verity is enabled on the system partition.
Use "adb disable-verity" to disable verity.
If you do not, remount may succeed, however, you will still not be able to write to these volumes.
remount of /system failed: Read-only file system
remount failed


running below command on PC also does not work

sudo mount -o remount,rw /system
mount: can't find /system in /etc/fstab or /etc/mtab


What should I do?

EDIT.

   which mount
    /bin/mount

adb version
Android Debug Bridge version 1.0.32


The output of mount command is as below

user$ mount
/dev/sda6 on / type ext3 (rw,errors=remount-ro)
proc on /proc type proc (rw,noexec,nosuid,nodev)
sysfs on /sys type sysfs (rw,noexec,nosuid,nodev)
none on /sys/fs/fuse/connections type fusectl (rw)
none on /sys/kernel/debug type debugfs (rw)
none on /sys/kernel/security type securityfs (rw)
udev on /dev type devtmpfs (rw,mode=0755)
devpts on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=0620)
tmpfs on /run type tmpfs (rw,noexec,nosuid,size=10%,mode=0755)
none on /run/lock type tmpfs (rw,noexec,nosuid,nodev,size=5242880)
none on /run/shm type tmpfs (rw,nosuid,nodev)
binfmt_misc on /proc/sys/fs/binfmt_misc type binfmt_misc (rw,noexec,nosuid,nodev)
gvfs-fuse-daemon on /home/user/.gvfs type fuse.gvfs-fuse-daemon (rw,nosuid,nodev,user=user)
/dev/sda5 on /media/Data type fuseblk (rw,nosuid,nodev,allow_other,default_permissions,blksize=4096)
/dev/sda2 on /media/OS type fuseblk (rw,nosuid,nodev,allow_other,default_permissions,blksize=4096)
The sequence of commands that worked for me was 

adb root
adb disable-verity
adb reboot
adb root
adb remount


If I don't reboot, remount does not succeed.