Make memory erasure feature compatible with overlayfs (#15146) · Issues · tails / tails

Make memory erasure feature compatible with overlayfs

Originally created by @intrigeri on #15146 (Redmine)

The “Erasure of the overlayfs read-write branch on shutdown” test scenario fails. But interestingly, “Tails erases memory on DVD boot medium removal: overlayfs read-write branch” passes. Looks like live-boot behaves slightly differently on overlayfs than on aufs, which seems to explain why mountpoints are not visible and can’t be unmounted and thus cleaned.

We need to update the design doc (wiki/src/contribute/design/memory_erasure.mdwn) to document the overlayfs implementation instead of the aufs one.

Feature Branch: bugfix/15146-overlayfs-memory-erasure+force-all-tests

Attachments

Related issues

Related to #8415 (closed)

_Originally created by @intrigeri on [#15146 (Redmine)](https://public-redmine-archive.tails.boum.org/code/issues/15146)_

The “Erasure of the overlayfs read-write branch on shutdown” test
scenario fails. But interestingly, “Tails erases memory on DVD boot
medium removal: overlayfs read-write branch” passes. Looks like
`live-boot` behaves slightly differently on overlayfs than on aufs,
which seems to explain why mountpoints are not visible and can’t be
unmounted and thus cleaned.

We need to update the [design
doc](https://tails.boum.org/contribute/design/memory_erasure/)
(`wiki/src/contribute/design/memory_erasure.mdwn`) to document the
overlayfs implementation instead of the aufs one.

Feature Branch: bugfix/15146-overlayfs-memory-erasure+force-all-tests

### Attachments

* [aufs.png](https://redmine.tails.boum.org/code/attachments/download/2467/aufs.png)
  * [overlayfs.png](https://redmine.tails.boum.org/code/attachments/download/2468/overlayfs.png)
  * [exposed-upper-dir-log-2.png](https://redmine.tails.boum.org/code/attachments/download/2470/exposed-upper-dir-log-2.png)
  * [exposed-upper-dir-log-1.png](https://redmine.tails.boum.org/code/attachments/download/2471/exposed-upper-dir-log-1.png)
  * [exposed-upper-dir-log-3.png](https://redmine.tails.boum.org/code/attachments/download/2472/exposed-upper-dir-log-3.png)
  * [exposed-upper-dir-log-4.png](https://redmine.tails.boum.org/code/attachments/download/2473/exposed-upper-dir-log-4.png)
  * [exposed-upper-dir-log-5.png](https://redmine.tails.boum.org/code/attachments/download/2474/exposed-upper-dir-log-5.png)
  * [exposed-upper-dir-log-6.png](https://redmine.tails.boum.org/code/attachments/download/2475/exposed-upper-dir-log-6.png)
  * [02_10_33_Tails_erases_memory_on_DVD_boot_medium_removal__overlayfs_read-write_branch.png](https://redmine.tails.boum.org/code/attachments/download/2525/02_10_33_Tails_erases_memory_on_DVD_boot_medium_removal__overlayfs_read-write_branch.png)
  * [02_10_33_Tails_erases_memory_on_DVD_boot_medium_removal__overlayfs_read-write_branch.mkv](https://redmine.tails.boum.org/code/attachments/download/2526/02_10_33_Tails_erases_memory_on_DVD_boot_medium_removal__overlayfs_read-write_branch.mkv)
  * [00_21_12_Tails_erases_memory_on_DVD_boot_medium_removal__overlayfs_read-write_branch.png](https://redmine.tails.boum.org/code/attachments/download/2534/00_21_12_Tails_erases_memory_on_DVD_boot_medium_removal__overlayfs_read-write_branch.png)
  * [00_21_12_Tails_erases_memory_on_DVD_boot_medium_removal__overlayfs_read-write_branch.mkv](https://redmine.tails.boum.org/code/attachments/download/2535/00_21_12_Tails_erases_memory_on_DVD_boot_medium_removal__overlayfs_read-write_branch.mkv)
  * [03_25_07_Tails_erases_memory_on_DVD_boot_medium_removal__overlayfs_read-write_branch.png](https://redmine.tails.boum.org/code/attachments/download/2551/03_25_07_Tails_erases_memory_on_DVD_boot_medium_removal__overlayfs_read-write_branch.png)
  * [03_25_07_Tails_erases_memory_on_DVD_boot_medium_removal__overlayfs_read-write_branch.mkv](https://redmine.tails.boum.org/code/attachments/download/2552/03_25_07_Tails_erases_memory_on_DVD_boot_medium_removal__overlayfs_read-write_branch.mkv)
  * [with-util-linux-mount-umount.png](https://redmine.tails.boum.org/code/attachments/download/2582/with-util-linux-mount-umount.png)

### Related issues

- **Related to** tails/tails#8415

Edited May 21, 2020 by intrigeri

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