That is correct, and at the current mempool size, those 100 allowed transactions are completely gone in 1 or 2 minutes... So if you want to use viabtc's txaccelerator, it's imperative you use it in the fist couple of seconds after a new hour has begon.

I guess your best bet would be to use the viabtc txaccelerator link in 34 minutes... That way you'd have a very decent shot at getting into a block within the next couple of hours. If you wait it out, there's a reasonable chance your tx will be dropped from the mempool of most nodes in 2.5 days.

https://www.mocacinno.com/feecheck.php?txid=34be82a7397236eb813e38a8da6429f2498d61a4988459a11e3ae5248da277f1

The fee was 121 sat/byte, while at the time of writing, you'd need 219 sat/byte for a 95% chance of getting into one of the next 3 blocks...
The webpage i posted lists the possible sollutions... If you wait untill exactly 14:00 CET (or 15:00 or 16:00 or...) you can use viabtc's txaccelerator, and you'll probably get a confirmation in 3 to 4 hours...

Could you post the txid? This way i can have a look at what could potentially be wrong...

cpp => c plus plus (c++)
This is basically just bitcoin core's sourcecode... it's not a wallet file, it does not hold private keys or any other personal information, it's just part of the sourcecode, the only thing you can do with it is compile it...

unless your friend has renamed his wallet.dat to wallet.cpp (but that would be a rather big coincidence). If you try to open the file with a text editor, and you can read the code, it's just sourcecode... If you see a bunch of gibberish characters, it might be a renamed wallet.

You should probably edit your post, since begging for donations is not allowed on this forum.

To find out which asic to buy, visit this page:
https://en.bitcoin.it/wiki/List_of_Bitcoin_mining_ASICs

Then visit this one
http://www.coinwarz.com/calculators/bitcoin-mining-calculator/

Enter the details of the asic you're intested in in the coinwarz calculator, as well as your electricity price, price of the ASIC,... And you'll see how long you'll take to break even AT THIS DIFFICULTY LEVEL AND BTC PRICE!!!

I'm currently working on an article about new users asking how to mine: http://www.mocacinno.com/blog/is-bitcoin-mining-equal-to-free-money-printing/
It's a first version, and i'll probably edit it some more over the next couple of days, but it should already give you a basic idear...

Could you post the transaction id from when you were sending bitcoin to another wallet?

You made a small mistake, you're talking about hardware wallets, not cold wallets. Maybe you can edit your title to, that way you'll get more to-the-point answers.

To answer your question: personally, i'd initialise each hardware wallet seperately, generate a seperate seed, and put 1/3th of my BTC on each ledger... However, it should be possible to initialise one ledger wallet, create a seed, and restore the other 2 wallets using this seed. This way, each wallet has controll over the same addresses (and unspent outputs), but has a different pin code.
This scenerio would come in handy if you have a business, and each partner would like to have full controll over all funds... Or if you want to give one to your wife or something...

BTW: a ledger nano S comes with a security card on which you write down your 24 word seed. If your ledger gets destroyed, you can use this seed to restore your wallet, so i wouldn't worry to much about losing or destroying your wallet... As long as you have those 24 words, you're fine

Here tou go: quoted

Je kan de seed ook opsplitsen in verschillende delen, en elk deel bij 2 of 3 vertrouwde personen achterlaten (eventueel zelfs licht encrypteren), je kan hem volledig encrypteren, je kan hem bij de bank in een kluis bewaren, je kan hem verstoppen in een lange tekst, je kan hem steganografish beschermen,... Of een combinatie van al deze technieken...

Persoonlijk heb ik zowel een trezor gehad, en heb ik nu 2 ledgers (de HW.1 en de nano S). Persoonlijk vond ik de trezor ietwat degelijker (hoewel de ledger zeker ook degelijk genoeg is). Ben wel volledig overgeschakeld op de ledger aangezien deze op het moment van overschakelen wat meer altcoins ondersteunde (hoewel ik niet veel altcoins heb, wou ik deze toch op m'n hardware wallet bewaren)

quoted

and verified

For normal endusers, a wallet is basically a piece of software that manages your private keys, and sums up the unspent outputs that can be spent by the addresses generated by the private keys it manages. That's all there is to it.

bitaddress.org generates a private key (preferably encrypts it), calculates the public key using this private key and hashes this one to generate the address. All of this can be done 100% offline. The network doesn't need to know any of this.
You can generate transactions whose outputs can be spent by the address on your paper wallet just like that, the network doesn't need any prior knowledge of your address, nor your public key, nor your private key in order to do this.
Once the address on your paper wallet has unspent outputs in the UTXO set, you can decrypt the private key on your paper wallet ,and import it into (for example) electrum.
Electrum will calculate the addresses, and scan the UTXO to see if there are outputs that can be spent by the address it generated based on the private key. Since you imported the private key into electrum, electrum can now use these unspent outputs to generate and sign new transactions (altough it's recommanded to use electrum's "sweep"-functionality instead...).

When you sweep a paper wallet, exactly the same happens: electrum fetches (and possibly decrypts) the private key, calculates the corresponding addres, scans the UTXO to find outputs, then derives a new address from your existing wallet and generates a transaction to use all unspent outputs that belong to your paper wallet as an input and uses the address it got from electrum as an output.

IF you are uncertain about what happens, i'd recommand you to generate a testnet paper wallet first: https://www.bitaddress.org/?testnet=true
you can fund this testnet paper wallet by using testnet faucets: https://www.google.com/search?q=bitcoin+testnet+faucet&oq=bitcoin+testnet+faucet
Then you can use a testnet wallet to sweep the testnet paper wallet: https://en.bitcoin.it/wiki/Testnet#Wallets (i'd probably recommand the testnet android wallet, or to install bitcoin core and start it with the -testnet argument)

When the exchange creates a transaction, he uses an unspent output that can be spend by one of their exchange addresses as an input to generate your withdrawal transaction.

Your withdrawal transaction uses this input to generate two outputs: one that can be spent by you, and one that can be spent by one of their change addresses.

A miner needs to include this withdrawal transaction into the block he/she is currently working on. To make it worth their wile, you have to pay a miners fee. The higher the miner's fee, the better the chance he'll add your transaction to a block.

The difference between (sum of inputs) and (sum of outputs) = fee.

BTW: the fee is calculated based on the size of the transaction, the size depends on the number of inputs and outputs (just for your future reference).

In your case, https://blockchain.info/tx/defe548b8af9098953053d8107c7763ede3b379144306642014b999745b8c0a4 said following:

Input = 0.390023 that can be spent by C91S6871QRTTTMdhVsQEv9LbdU684eamg (an exchange address)
Output 1 = 0.36701145 that can be spent by 1BK8SiGnb51ZNcGoUgLQqEnsxVvYrsDJpU (blockchain thinks this is the exchange's change address)
Output 2 = 0.02251155 that can be spent by 1C1crrhX2A3QeS4P7QMExRayVUr4c9Asej (blockchain thinks this is your address)

0.390023 - (0.36701145 + 0.02251155) = 0.0005 (this is the miner's fee)

The size of your transaction with 1 input and 2 outputs is 225 bytes. This makes the fee 50000 satoshi's/255 bytes =~ 200 sat/byte

Here's an image out of the bitcoin.org developer guide that will show the basis of transactions graphically (it can get a lot more complex than this tough):

source: https://bitcoin.org/en/developer-guide#block-chain-overview

If you don't care about your privacy, just an ordinary bip38 encrypted paper wallet should work fine to store your funds safely for a longer time.
You don't need the 12 words backup.... A paper wallet contains the bip38 encrypted private key, there are loads of wallets that can import the private key directly, including core and electrum.
If you would make a paper wallet from your 12 seed words, you'd more or less be bound to one or two wallet providers, since you'd need to restore the wallet using software that uses the same mechanism (both the mnemonic and the derivation path), while a bip38 encrypted private key can be imported by far more wallets.

If you worry about your privacy, generate 4 or 5 seperate paper wallets.

A hardware wallet costs a bit of money, but AFAIK, allmost all recent hardware wallets are HD wallets, which improves your privacy, plus you have the added advantage of being able to use the hardware wallet like a desktop wallet (a paper wallet should be discarded once you sweep it... so it's fine to keep depositing funds to your paper wallet, but once you want to withdraw, you should withdraw everything and never use that same paper wallet again)

Only one of those... Why would you want to use a HD paper wallet? each of those recomandations has it's own pro/cons depending on your usecase.

You're asking a difficult question here... AFAIK, there is no paper wallet generator that generates HD wallets, since this would be very complex to generate AND to use. Creating a deposit address when you only have the seed is a complex procedure. Also, printing the seed or xprv on a piece of paper seems unsecure to me... You'd have to encrypt your seed using a strong encryption algorithm yourself.
Why do you want this?

If you really want a HD paper wallet, i guess the only real option you'd have is to generate one yourself.
What you *could* do, is run electrum offline, generate a new wallet, export the xprv or the seed words... Encrypt either the xprv or the seed words.. Then export the QR code of the xpub, and export a list of x addresses (set the gap limit).

Create a piece of paper containing the encrypted xprv or the encrypted seed words, together with a list of the first 100 derived addresses from the xpub... Maybe paste the QR of the xpub somewhere on the piece of paper to, so you could derive some more addresses if needed...
After you're done, move the selfmade paper wallet using a usbstick to a printer and print it out.

Your paper wallet's security will only be as strong as the encryption scheme you used to encrypt your xprv or seed tough... And you'd always have to use wallet software that uses the same derivation path...

IMHO, it would be easyer AND SAFER to:
- use a cold wallet setup
- just generate a couple hundred addresses using https://www.bitaddress.org/
- just buy a cheap ledger or trezor

It's certainly doable. Since you're going to use python, why don't you just derive new addresses from an xpub?
Start electrum on an offline machine, generate a new seed, export the xpub to an usb drive, use python to derive new addresses...

Here is some code i wrote a long time ago to accomplish this:
https://bitcointalk.org/index.php?topic=1682523.msg17027986#msg17027986

Cut out the middle man (the centralised, online, wallet provider), keep everything safe

Er is geen magisch getal 225 bytes. Elke transactie kan zijn eigen grootte hebben, 225 bytes is een gemiddelde grootte voor een transactie met 1 input en 2 outputs.
Normaal gezien kiest je wallet in jouw plaats welke inputs hij gaat gebruiken, en welke outputs hij gaat aanmaken. Op basis van het aantal inputs, outputs en de adressen die gebruikt werden kan je wallet vrij makkelijk uitrekenen hoe groot je transactie gaat worden.
Het is nu echter zo dat bijvoorbeeld blockchain en oudere versies van electrum hier volledig uit de bocht gaan. Hun algorithme om de grootte van de transactie te berekenen zit regelmatig volledig verkeerd, ofwel gaan ze uit de bocht bij het kiezen van hoeveel sat/byte optimaal is op dat moment (idk).

Het is ook zo dat de fees die je best betaald per byte verschilt van dag tot dag. Als de mempool vol zit met unconfirmed transacties met een hoge fee/byte, zal jij een nog hogere fee/byte moeten betalen als je wilt dat de miners jouw transactie kiezen. Als een weekje later de mempool bijna leeg is, en de transacties die erin zitten een lage fee/byte hebben, zal je véél minder moeten betalen om even snel aan een confirmatie te geraken.

Er zijn een aantal soorten transacties, de grootte van verschillende soorten transactie kan wel degelijk licht verschillen, bijvoorbeeld afhankelijk van of je een compressed of uncompressed adres gebruikt...
Ook is er een verschil tussen P2PKH en P2SH*
Maar eigenlijk is dat voor de dagdagelijkse gebruiker onbelangrijk.

Besef wel dat het gaat over 300 satoshi's PER BYTE... Niet over 300 satoshi's. Dus een transactie van 225 bytes = 225*300 = 67500 satoshi's = 0.000675 BTC


*
https://bitcoin.org/en/glossary/p2sh-address
https://bitcoin.org/en/glossary/p2pkh-address

Basically, you should never accept 0-conf transactions. If you're on the receiving end, never pay or deliver any product before a transaction has at least 1 confirmation.... If you're accepting 0.1BTC or more, i'd even advice to to wait for at least 3+ confirmations. I know this advice comes way to late in your case, and i agree that wallet software providers should probably make a bigger effort in marking unconfirmed transactions in their GUI, so new members don't get scammed by accepting 0-conf transactions.