[pkg-cryptsetup-devel] Bug#1016474: cryptsetup: The system installed on encrypted LVM (both root and swap partitions) freezes during massive writes

[Wojciech Zabołotny]

W dniu 01.08.2022 o 13:31, Wojciech Zabołotny pisze:
> W dniu 01.08.2022 o 13:12, Guilhem Moulin pisze:
>> Control: tag -1 + moreinfo
>>
>> Hi,
>>
>> On Mon, 01 Aug 2022 at 12:27:39 +0200, Wojciech Zabołotny wrote:
>>> That configuration generally works, but if a massive write operations
>>> are performed, the syste, practically freezes.
>> What makes you think that is a src:cryptsetup issue?  Nothing in this
>> package is involved once the device has been mapped.
>>
> Hi, the problem is indeed complex. I'm not sure that it is really a
> cryptsetup issue.
> It may be related to incorrect assignment of priorities to kernel
> threads responsible for encryption and swapping.
>
> The problem is also not new:
> https://superuser.com/questions/1666684/debian-testing-linux-on-an-encrypted-lvm-filesystem-intensive-operations-cause
>
> Then it seemed that it is related to lack of entropy, but installation
> of haveged didn't solve the problem.
>
> Well, maybe I should try recipes given here:
> https://askubuntu.com/questions/1406444/what-is-causing-my-system-to-stall-freeze-corrupt-data-when-using-lvm-luks
> and here: https://blog.cloudflare.com/speeding-up-linux-disk-encryption/

Hi,

I have tried to modify the mapping parameters with:

 # cryptsetup  --perf-no_write_workqueue refresh sda6_crypt

(as proposed in
https://askubuntu.com/questions/1406444/what-is-causing-my-system-to-stall-freeze-corrupt-data-when-using-lvm-luks
)

The first tests show that it eliminates the problem of system freeze. I
have yet to check how does it affect the overall performance of the
filesystem.

With best regards,
Wojtek