Public bug reported: I noticed that my encrypted swap was not working, and I found that the randomly generated encrypted filesystem had randomly generated data that had the magic number of a filesystem type, and hence ever more it refused to start...
Eg:- root@hardline:/etc# more /etc/crypttab cryptswap1 /dev/sda3 /dev/urandom swap,cipher=aes-cbc-essiv:sha256 root@hardline:/etc# cryptdisks_start cryptswap1 * Starting crypto disk... * cryptswap1 (starting).. * cryptswap1: the precheck for '/dev/sda3' failed: - The device /dev/sda3 contains a filesystem type hfsplus. * cryptswap1 (failed)... [fail] Obviosuly this is not a filesystem:- root@hardline:/etc# mount -t hfsplus /dev/sda3 /mnt mount: wrong fs type, bad option, bad superblock on /dev/sda3, missing codepage or helper program, or other error So I blanked it and restarted, all is now well... perhaps if there's a force option on cryptsetup this should be used in the setup scripts:- root@hardline:/etc# dd if=/dev/zero of=/dev/sda3 ^C684121+0 records in 684121+0 records out 350269952 bytes (350 MB) copied, 5.96378 s, 58.7 MB/s root@hardline:/etc# cryptdisks_start cryptswap1 * Starting crypto disk... * cryptswap1 (starting).. * cryptswap1 (started)... [ OK ] ** Affects: linux (Ubuntu) Importance: Undecided Status: Incomplete -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1386339 Title: cryptswap can fail if random data matches a filesystem magic number Status in “linux” package in Ubuntu: Incomplete Bug description: I noticed that my encrypted swap was not working, and I found that the randomly generated encrypted filesystem had randomly generated data that had the magic number of a filesystem type, and hence ever more it refused to start... Eg:- root@hardline:/etc# more /etc/crypttab cryptswap1 /dev/sda3 /dev/urandom swap,cipher=aes-cbc-essiv:sha256 root@hardline:/etc# cryptdisks_start cryptswap1 * Starting crypto disk... * cryptswap1 (starting).. * cryptswap1: the precheck for '/dev/sda3' failed: - The device /dev/sda3 contains a filesystem type hfsplus. * cryptswap1 (failed)... [fail] Obviosuly this is not a filesystem:- root@hardline:/etc# mount -t hfsplus /dev/sda3 /mnt mount: wrong fs type, bad option, bad superblock on /dev/sda3, missing codepage or helper program, or other error So I blanked it and restarted, all is now well... perhaps if there's a force option on cryptsetup this should be used in the setup scripts:- root@hardline:/etc# dd if=/dev/zero of=/dev/sda3 ^C684121+0 records in 684121+0 records out 350269952 bytes (350 MB) copied, 5.96378 s, 58.7 MB/s root@hardline:/etc# cryptdisks_start cryptswap1 * Starting crypto disk... * cryptswap1 (starting).. * cryptswap1 (started)... [ OK ] To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1386339/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp