TS-251+, newest QTS Version.
Dear sir or madame,
while i‘m booting the system partition is unencrypted. The File Partition is encrypted.
My Question is: Where save QTS the Temp File (copied files , key from the encrypted partition and so on. Everything who shall be in swap)? in the encrypted Part of HDD? Or use QTS RAM as swap (Temp filed only in the RAM).
This shall be important, if the key for the file partition stored in unencrypted Temp files.
Thank you for your help.
Sincerely yours.
How did you manage that? QNAP don’t offer a QuTS hero version for the TS-251+.
Your firmware should be QTS. 
Yea,I have a TVS-882 I would like to put hero on.
Yes, thank you for the correction 
. I do not know, why my Autocorrection make QTS zu QuTS, but thank you for the tip.
No worries. 
To your actual questions: QTS temp files are only written to tmpfs (kinda like a RAM disk).
Persistent files are stored either on a userdata volume (only possible if the user has installed hard drives, SSDs, etc…), or on the DOM (a small rewritable memory chip used like any other block device, and an integral part of the NAS hardware). QTS will manage its own persistent files and locations.
With regard to decrypting a LUKS partition: I think this presents in the OS as a virtual block device. I don’t think files are written to disk in an unencrypted state. I could be wrong - hopefully someone will correct me if this is so. 
For the location of the decryption key: https://www.reddit.com/r/qnap/comments/1nsrqgj/comment/nh10btr
… and reproduced here for posterity:
If you select the option “Save encryption key” the passphrase will be saved in partition 6 of the DOM, this is an example of a nas with 2 volumes with encryption, one is saved and the other one, no.
[~] # strings /dev/sdc6 |grep ENCK
ENCK=
ENCK=$1$YCCaQNAP$GaSmhKtvVmkUDf3b.EcKH/
Thank you for your answer. I have my key not saved. But if everything temp file is only in tempfs, than this is fine. I habe encrypted my whole data partition and i write my password everytime i reboot my NAS.
If this is so correct, thank i will be fine. Thank you 
Thanks for the question! We’d love to understand a bit more about what you’re trying to achieve — could you share your use case or what you’re hoping to do?
Hello SteveKo,
thank you for your message.
Normally Full-Disk-Encryption means, that everything is encrypted until the password is correct. But in my NAS the OS is unencrypted and only the File partition is encrypted. In security sight, temp files could be a security risk. And my question is only, is the unencrypted OS configured that no temp files written to the hard drive? If temp files are written to unencrypted hard drive (e.g. swap partition on the unencrypted partition), than a security risk will be happen. Because key material or metadata could be safed on the swap partition on the unencrypted partition.
I hope i have written my question more clearly.
Sincerely yours,
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