Shamelessly stolen from Rodney Barnhardt,
https://www.experts-exchange.com/questions/28129776/Data-Domain-DR530-Password-Recovery.html#answer391944361.Connect to the serial port with the following settings:
o 9600 baud
o 8 data bits
o none/no parity
o 1 stop bit
o none/no flow control
2.Reboot the Data Domain system
3.During RAM test hit one of the following keys (BIOS version depends on which one works)
a.Delete
b.F12
c.F2
d.ESC 2
4.Enter the password, which from what you say, yours should be: d500d
5.Select Server Management (or advanced) and then Console Redirection
6.Set Legacy OS Redirection to ON (MAKE SURE NO OTHER CHANGES ARE MADE!)
7.It will look like it is rebooting, hit the TAB key at the boot screen
8.Type “p” at the prompt and enter the following password: ddrc0s (that is a zero)
9.Select “a” to append the boot-serial option
10.Make the following change by adding this to the kernel boot line: goto-bash console=ttyS0 (this is a zero)
11.Hit ENTER to save the change and then press “b” to continue booting.
12.When the reboot halts, enter the following commands
a.mv /bin/sh x
b.ln –s /bin/bash /bin/sh
c.dd_bootmodule --reassemble-only
13.Use the following command to get the root name: cat /proc/cmdline
14.Depending on what is returned, you will use the following to mount the device:
a.If root=/dev/root-pl1, use dd_dg00p15
b.If root=/dev/root-pl2, use dd_dg00p5
c.If root=/dev/dd_dg00p15, use dd_dg00p15
15.Mount using the results from above. EXAMPLE: mount /dev/dd_dg00p5
16.Edit the shadow file in vi by typing : vi /sysroot/etc/shadow
17.Remove the encrypted password from the sysadmin account. The line will look something like this: “sysadmin:#3465@^fg/$GJITFD:13371:0:99999:7:::” After editing, it should look like the following:”sysadmin::13371:0:99999:7:::
18.Enter :wq to save and exit the editor
19.Then enter the following commands to properly exit and reboot:
a.sync; sync; sync
b.cd/
c.umount /sysroot
d.reboot
20.Once the system has rebooted, create a new password with the following command: user change password sysadmin