Updating FabricOS using scp - The server is inaccessible or firmware path is invalid.

If you're getting something like this during updating brocade san switch firmware:
 
Failed to access scp://oracle:**********@hostname//vol200/temp/hp_hba/brocade/fos_721b/v7.2.1b/release.plist
The server is inaccessible or firmware path is invalid. Please make sure the server name/IP address and the firmware path are valid, the protocol and authentication are supported. It is also possible that the RSA host key could have been changed and please contact the System Administrator for adding the correct host key.

than you have two options :

1. Use ftp server to download firmware (I tried with vsftpd, but having trouble with binary/ascii mode having completely disabling ascii in the config I've left it).

2. Modify sshd_config, because firmwaredownload over scp/sftp require plain ssh password authentication

PasswordAuthentication yes

Reboot ssh server and have a lot of fun.
P.S.  Avoid ssh passwords with spaces for firmwaredownload.

How to free up space, "used" by deleted file which is held by running application

1. Just kill your application

2. If you can't kill the application, you can :

a) figure out the pid of the app;
b) figure out deteled filename (lsof | grep deleted | grep pid)
c) run

# : > /proc/$app_pid/fd/$decrpiptor_corresponding_to_deleted_file