Category Archives: How to

Turn on Wi-Fi on Netgear Nighthawk D7000 using telnet

This procedure works even if the physical button on the device has been pressed to shut down Wi-Fi.

Enable telnet

Assuming your device’s IP is 192.168.1.1:

$ wget --quiet --user=admin --password='password' -O- http://192.168.1.1/setup.cgi?todo=debug; echo

Enter the device

$ telnet 192.168.1.1
Trying 192.168.1.1...
Connected to 192.168.1.1.
Escape character is '^]'.
D7000 login: admin
Password: 
# 

Set physical button on

# nvram set wifi_btn_on=1

Restart WLAN

# /usr/sbin/rc_app/rc_wlan start

Install UBCD on a bootable USB stick

Ultimate Boot CD was a really good tool when I worked as a sysadmin and I thought it was a good thing to keep a USB stick around.

Download UBCD

There are several options to download a copy of UBCD iso, all listed on the dedicated page. A good way is to use torrent (here’s the magnet link).

Indetify your USB device

Please be careful here, if you are wrong, you are going to delete the wrong disk.
I’m not responsible of any data you loose.

There are few ways to detect the right USB device, I usually take a look do dmesg output

$ dmesg | grep -A8 'Direct-Access'
[  844.712601] scsi 6:0:0:0: Direct-Access     Generic  Flash Disk       8.07 PQ: 0 ANSI: 2
[  844.713050] sd 6:0:0:0: Attached scsi generic sg2 type 0
[  844.716347] sd 6:0:0:0: [sdc] 15663104 512-byte logical blocks: (8.01 GB/7.46 GiB)
[  844.716774] sd 6:0:0:0: [sdc] Write Protect is off
[  844.716780] sd 6:0:0:0: [sdc] Mode Sense: 03 00 00 00
[  844.716969] sd 6:0:0:0: [sdc] No Caching mode page found
[  844.716972] sd 6:0:0:0: [sdc] Assuming drive cache: write through
[  844.719175]  sdc: sdc1
[  844.720364] sd 6:0:0:0: [sdc] Attached SCSI removable disk

In this case I’m sure that the device is sdc because I’ve only one disk with 8GB of storage.

I’ll use sdc in this document, you should use your device name, it’s really important.

Format the USB stick

Be sure that the OS you are running have not automatically mounted any previous partition on the stick:

$ sudo umount /dev/sdc*

Then you could use GParted or do it manually as I like.

$ sudo parted -s /dev/sdc mklabel msdos
$ sudo parted -s /dev/sdc mkpart primary fat32 0 700
$ sudo parted -s /dev/sdc set 1 boot on
$ sudo mkfs.vfat -F32 /dev/sdc1
$ sudo parted -s /dev/sdc print
Model: Generic Flash Disk (scsi)
Disk /dev/sdc: 8020MB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags:

Number  Start  End    Size   Type     File system  Flags
 1      512B   700MB  700MB  primary               boot, lba

Extract ISO data on a folder

$ mkdir ubcd534
$ sudo mount -o loop,ro ubcd534.iso /mnt/misc/
$ rsync -avr /mnt/misc/ ubcd534/
$ sudo umount /mnt/misc

Copy ISO data to USB

$ sudo mount /dev/sdc1 /mnt/misc/
$ sudo rsync -rtv ubcd534/ /mnt/misc/
$ sudo umount /dev/sdc1

Make the USB device bootable

$ cd ubcd534/ubcd/tools/linux/ubcd2usb
$ chmod +x syslinux
$ sudo ./syslinux -s -d /boot/syslinux -i /dev/sdc1

Statically compile redis 3.0.2 on CentOS 5 (RHEL 5)

How to statically compile redis 3.0.2 on CentOS 5 (RHEL 5)

wget http://download.redis.io/releases/redis-3.0.2.tar.gz
wget http://prdownloads.sourceforge.net/tcl/tcl8.5.18-src.tar.gz

Install tcl8.5

tar xfz tcl8.5.18-src.tar.gz
cd tcl8.5.18/unix
./configure
make
make test
make install

Compile redis

Statically linked binaries

make CFLAGS="-static" EXEEXT="-static" LDFLAGS="-I/usr/local/include/"

Dynamically linked binaries

make LDFLAGS="-I/usr/local/include/"

How to manually install redis

cd src/
cp redis-{server,cli} /usr/local/bin/
chown root: /usr/local/bin/redis-{server,cli}
chmod 755 /usr/local/bin/redis-{server,cli}
mkdir /{var,etc}/redis /var/redis/6379
chmod 775 /{var,etc}/redis
cp redis.conf /etc/redis/6379.conf
sed -i 's/daemonize no/daemonize yes/' /etc/redis/6379.conf
sed -i 's,pidfile /var/run/redis.pid,pidfile /var/run/redis_6379.pid,' /etc/redis/6379.conf
sed -i 's/^# bind 127.0.0.1/bind 127.0.0.1/' /etc/redis/6379.conf
sed -i 's,logfile "",logfile "/var/log/redis_6379.log",' /etc/redis/6379.conf
sed -i 's,dir ./,dir /var/redis/6379,' /etc/redis/6379.conf