Re: Slow unlock of the LUKS device at boot

# Observation

For the slow partition (that uses LUKS2 and has LVM) takes about 6 
minutes to test passphrase as follows and returns a warning "No usable 
token is available."

```bash
sudo cryptsetup -v open --test-passphrase --type luks /dev/nvme0n1p5 
--key-file /etc/luks/boot_os.keyfile
sudo cryptsetup -v open --test-passphrase --type luks /dev/nvme0n1p5
```

For the boot partition (LUKS1), which used the same passphrase and 
keyfile as the above partition it takes just 5 seconds to test passphrase


```bash
sudo cryptsetup -v open --test-passphrase --type luks /dev/nvme0n1p1 
--key-file /etc/luks/boot_os.keyfile
sudo cryptsetup -v open --test-passphrase --type luks /dev/nvme0n1p1
```

---

Also, I did cryptsetup benchmark as follows

   ``` bash
   $ cryptsetup benchmark
   # Tests are approximate using memory only (no storage IO).
   PBKDF2-sha1      2631307 iterations per second for 256-bit key
   PBKDF2-sha256    5637505 iterations per second for 256-bit key
   PBKDF2-sha512    2118335 iterations per second for 256-bit key
   PBKDF2-ripemd160 1115506 iterations per second for 256-bit key
   PBKDF2-whirlpool 1006310 iterations per second for 256-bit key
   argon2i       9 iterations, 1048576 memory, 4 parallel threads (CPUs) 
for 256-bit key (requested 2000 ms time)
   argon2id      9 iterations, 1048576 memory, 4 parallel threads (CPUs) 
for 256-bit key (requested 2000 ms time)
   #     Algorithm |       Key |      Encryption |      Decryption
           aes-cbc        128b      1727.7 MiB/s      6931.8 MiB/s
       serpent-cbc        128b       116.2 MiB/s       868.9 MiB/s
       twofish-cbc        128b       252.9 MiB/s       566.7 MiB/s
           aes-cbc        256b      1313.0 MiB/s      5684.8 MiB/s
       serpent-cbc        256b       120.3 MiB/s       867.2 MiB/s
       twofish-cbc        256b       257.5 MiB/s       563.5 MiB/s
           aes-xts        256b      5342.5 MiB/s      5333.8 MiB/s
       serpent-xts        256b       748.8 MiB/s       783.1 MiB/s
       twofish-xts        256b       517.7 MiB/s       530.6 MiB/s
           aes-xts        512b      4779.9 MiB/s      4819.2 MiB/s
       serpent-xts        512b       756.1 MiB/s       779.9 MiB/s
       twofish-xts        512b       521.5 MiB/s       529.2 MiB/s
   ```



- Is the warning responsible for this slow behavior: "No usable token is 
available." Or can you suggest if I should tweak some key parameters or 
change the order of keys in keyslots.


-- 
Thanks and Regards

Lamy