Resize ext4 partition on CentOS 5

When trying to resize an ext4 partition on CentOS 5, I got an error:

$ resize2fs /dev/sdf
resize2fs 1.39 (29-May-2006)
resize2fs: Filesystem has unsupported feature(s) while trying to open /dev/sdf
Couldn't find valid filesystem superblock.

Google around and found out we must use resize4fs instead

$ resize4fs /dev/sdf
resize4fs 1.41.12 (17-May-2010)
Filesystem at /dev/sdf is mounted on /opt; on-line resizing required
old desc_blocks = 5, new_desc_blocks = 7
Performing an on-line resize of /dev/sdf to 26214400 (4k) blocks.

Similarly, we will use fsck.ext4, tune4fs for ext4

Cisco SPA525G2 SIP configuration over wireless connection

We bought a new Cisco SPA525G2 phone to use wireless and need to setup it with RingCentral.

It's pretty simple so we don't need provisioning via private TFTP server like old Cisco 7940/7960 phones.

Below is how I made it work.

1. Config the phone to connect the wireless router. (since I work from home so need someone in the office helping on this).

2. Remote to a PC in the same phone's network, open the browser and enter the phone's IP address.
If it asks user/password to login, enter: admin / (blank password)

3. Config the phone:
Suppose the RingCentral provides provision information:
SIP Domain sip.ringcentral.com:5060
Outbound Proxy sip10.ringcentral.com:5090
User Name 14151234567
Password aPassword
Authorization ID 0123456789

On the Cisco admin UI, click the Advance on bottom of the page.

Menu Provisioning
Provision Enable: No

Menu Voice > Ext 1
SIP Transport: TCP
Proxy: sip.ringcentral.com:5060
Outbound Proxy: sip10.ringcentral.com:5090
Use Outbound Proxy: Yes
Display Name: a name
User ID: 14151234567
Password: aPassword
Use Auth ID: Yes
Auth ID: 0123456789

Menu System
Primary NTP Server: 0.north-america.pool.ntp.org
Secondary NTP Server: 1.north-america.pool.ntp.org

Click "Submit All Changes"

Then check the phone status to see if the line 1 is Registered or not.