Can't mount /system please help devs

while flashing my phone restarted and was stuck in booting image
when i went to cwm recovery it showed
E: Can't mount /cache/recovery/command
E: Can't mount /cache/recovery/log
E: Can't open /cache/recovery/log
E: Can't mount /cache/recovery/last_log
E: Can't open /cache/recovery/last_log

when i try to restore mt backup
It shows an error after "Checking MD5 sums...
Erasing boot before restore
Restoring boot image
Restoring system
Can't mount /system

i have tried to repair phone via sony pc companion
nd tried perfect brush from WM brush tool but it fails after 10%