How to install the Virtualbox SDK

Download and extract the SDK package. The target directory will be sdk.

If we try to execute directly the installer we will get:

python sdk/installer/ install
Traceback (most recent call last):
  File "sdk/installer/", line 88, in <module>
  File "sdk/installer/", line 61, in main
    raise Exception("No VBOX_INSTALL_PATH defined, exiting")
Exception: No VBOX_INSTALL_PATH defined, exiting

To install correctly we have to launch locally the install script.

cd sdk/installer
export VBOX_INSTALL_PATH=$(which virtualbox)
sudo -E python install

ASUS WL-500GP v2: flash firmware using CFE

I had a bricked router Asus WL500GP v2, luckily the CFE bootloader was still reachable through serial port. After setup a TFTP server and downloaded the appropriate upgraded firmware from OpenWrt, the CFE command was:

flash -noheader flash1.trx


  • flash1.trx is the destination flash (and not flash0.trx as I saw in some tutorials)
  • is the TFTP server IP
  • openwrt.trx is the firmware image
  • -no header is that option to override header verification

Synology DSM: how to renew Let’s Encrypt certificates with just one command

This method has been tested on DS214+ running DSM 6.0.2-8451 Update 9.

Connect to your Synology NAS through SSH as root user

ssh root@ds214


/usr/syno/sbin/syno-letsencrypt renew-all -vv

All expired certificates will be immediately renovated

Synology running Owncloud : fix “No memory cache has been configured” error

I have ownCloud running on my Synology DSM6 DS214+.

In the admin configuration page the Security & setup warnings section reports:

No memory cache has been configured. To enhance your performance please configure a memcache if available.
Further information can be found in our documentation.
Please double check the installation guides ↗, and check for any errors or warnings in the log.

How to fix:

Be sure the PHP cache option on Synology is set (Web Station => PHP Settings => Enable PHP Cache).

Edit the configuration file <owncloud_root_dir>/config/config.php adding the following line:

'memcache.local' => '\OC\Memcache\APCu',

Cache feature will start to work immediately

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