It's important to keep on top of wallet updates when operating nixd on a VPS. Wallet updates are often mandatory, but are usually released with a grace period of several days before the operator is required to update.
Log into your VPS and use wget to download the latest version:
Unpack the file with:
tar -zxvf nix-3.0.9-x86_64-linux-gnu.tar.gz
As the root user, install the binaries with:
cp nix-3.0.9/bin/* /usr/bin/
If you used the auto-installer script from CryptoSharks, you'll need to use his auto-updater to bring your VPS up to date with the latest version. The update script itself needs to get updated so wait until it's ready.
Update the script with:
rm nix_update.sh* wget -q https://raw.githubusercontent.com/cryptosharks131/Ghostnode/master/nix_update.sh./nix_update.sh
If used for staking, unlock with:
nix-cli walletpassphrase YOURWALLETPASSPHRASE 0 true
Finally, delete your bash history to remove your passphrase from both the history file and system memory.
history -c;history -w