I think I had an encrypted swap partition, because I chose to encrypt my home directory during the installation. I believe that's what the line with /dev/mapper/cryptswap1 ... in my /etc/fstab is all about.
I did something to bork my swap because on the next boot, I got a message (paraphrased):
The disk drive for /dev/mapper/cryptswap1 is not ready yet or not present. Wait to continue. Press S to skip or M to manually recover.
(As a side note, pressing S or M seemed to do nothing different from just waiting.)
Here's what I've tried:
This tutorial on how to fix the swap partition not mounting. However, in the above, the mkswap command fails because the device is busy.
So I booted from a live USB, ran GParted to reformat the swap partition (which showed up as an unknown fs type), and chrooted into the broken system to try that tutorial again. I also adjusted /etc/initramfs-tools/conf.d/resume and /etc/fstab to reflect the new UUID generated from formatting the partition as a swap. That still didn't work; instead of /dev/mapper/cryptswap1 not present, "The disk drive with UUID=[swap partition's UUID] is not ready yet or not present..."
So I decided to start afresh as though I never had created a swap partition in the first place. From the Live USB, I deleted the swap partition altogether (which, again showed up in GParted as an unknown fs type), removed the swap and cryptswap entries in /etc/fstab as well as removed /etc/initramfs-tools/conf.d/resume and /etc/crypttab. At this point the main system shouldn't be considered broken because there is no swap partition and no instructions to mount one, right? I didn't get any errors during startup. I followed the same instructions to create and encrypt the swap partition, starting with creating a partition for the swap, though I think fdisk said a reboot was necessary to see changes.
I was confident the 3rd process above would work, but the problem yet persists.
Some relevant info (/dev/sda8 is the swap partition):
/etc/fstab file:
# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point> <type> <options> <dump> <pass>
proc /proc proc nodev,noexec,nosuid 0 0
# / was on /dev/sda6 during installation
UUID=4c11e82c-5fe9-49d5-92d9-cdaa6865c991 / ext4 errors=remount-ro 0 1
# /boot was on /dev/sda5 during installation
UUID=4031413e-e89f-49a9-b54c-e887286bb15e /boot ext4 defaults 0 2
# /home was on /dev/sda7 during installation
UUID=d5bbfc6f-482a-464e-9f26-fd213230ae84 /home ext4 defaults 0 2
# swap was on /dev/sda8 during installation
UUID=5da2c720-8787-4332-9317-7d96cf1e9b80 none swap sw 0 0
/dev/mapper/cryptswap1 none swap sw 0 0
output of sudo mount:
/dev/sda6 on / type ext4 (rw,errors=remount-ro)
proc on /proc type proc (rw,noexec,nosuid,nodev)
sysfs on /sys type sysfs (rw,noexec,nosuid,nodev)
none on /sys/fs/fuse/connections type fusectl (rw)
none on /sys/kernel/debug type debugfs (rw)
none on /sys/kernel/security type securityfs (rw)
udev on /dev type devtmpfs (rw,mode=0755)
devpts on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=0620)
tmpfs on /run type tmpfs (rw,noexec,nosuid,size=10%,mode=0755)
none on /run/lock type tmpfs (rw,noexec,nosuid,nodev,size=5242880)
none on /run/shm type tmpfs (rw,nosuid,nodev)
/dev/sda5 on /boot type ext4 (rw)
/dev/sda7 on /home type ext4 (rw)
/home/undisclosed/.Private on /home/undisclosed type ecryptfs (ecryptfs_check_dev_ruid,ecryptfs_cipher=aes,ecryptfs_key_bytes=16,ecryptfs_unlink_sigs,ecryptfs_sig=cbae1771abd34009,ecryptfs_fnek_sig=7cefe2f59aab8e58)
gvfs-fuse-daemon on /home/undisclosed/.gvfs type fuse.gvfs-fuse-daemon (rw,nosuid,nodev,user=undisclosed)
output of sudo blkid (note that /dev/sda8 is missing):
/dev/sda1: LABEL="SYSTEM" UUID="960490E80490CC9D" TYPE="ntfs"
/dev/sda2: UUID="D4043140043126C0" TYPE="ntfs"
/dev/sda3: LABEL="Shared" UUID="80F613E1F613D5EE" TYPE="ntfs"
/dev/sda5: UUID="4031413e-e89f-49a9-b54c-e887286bb15e" TYPE="ext4"
/dev/sda6: UUID="4c11e82c-5fe9-49d5-92d9-cdaa6865c991" TYPE="ext4"
/dev/sda7: UUID="d5bbfc6f-482a-464e-9f26-fd213230ae84" TYPE="ext4"
/dev/mapper/cryptswap1: UUID="41fa147a-3e2c-4e61-b29b-3f240fffbba0" TYPE="swap"
output of sudo fdisk -l:
Disk /dev/mapper/cryptswap1 doesn't contain a valid partition table
Disk /dev/sda: 320.1 GB, 320072933376 bytes
255 heads, 63 sectors/track, 38913 cylinders, total 625142448 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xdec3fed2
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 409599 203776 7 HPFS/NTFS/exFAT
/dev/sda2 409600 210135039 104862720 7 HPFS/NTFS/exFAT
/dev/sda3 210135040 415422463 102643712 7 HPFS/NTFS/exFAT
/dev/sda4 415424510 625141759 104858625 5 Extended
/dev/sda5 415424512 415922175 248832 83 Linux
/dev/sda6 415924224 515921919 49998848 83 Linux
/dev/sda7 515923968 621389823 52732928 83 Linux
/dev/sda8 621391872 625141759 1874944 82 Linux swap / Solaris
Disk /dev/mapper/cryptswap1: 1919 MB, 1919942656 bytes
255 heads, 63 sectors/track, 233 cylinders, total 3749888 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xaf5321b5
/etc/initramfs-tools/conf.d/resume file:
RESUME=UUID=5da2c720-8787-4332-9317-7d96cf1e9b80
/etc/crypttab file:
cryptswap1 /dev/sda8 /dev/urandom swap,cipher=aes-cbc-essiv:sha256
output of sudo swapon -as:
Filename Type Size Used Priority
/dev/mapper/cryptswap1 partition 1874940 0 -1
output of sudo free -m:
total used free shared buffers cached
Mem: 1476 1296 179 0 35 671
-/+ buffers/cache: 590 886
Swap: 1830 0 1830
So, how can this be fixed?