RAM vs swap
Setting vm.swappiness=10 is wrong wrong wrong for 4G RAM with an i3. This is why your file copies fail. Set it back to 60 now... and we may change it more later.
Set drive caching and I/O Scheduling back to default.
free -h and grep -i swap /etc/fstab show me 4G RAM and a 2G /swapfile. The /swapfile is probably too small for your system, so we'll make it twice the size, like this:
Bigger /swapfile
Warning: Be careful. Improper use of the dd command can cause file loss. Best to copy/paste.
free -h # confirm 4G RAM and 2G swap
sudo swapoff -a # turn off swap
sudo rm -i /swapfile # remove old /swapfile
sudo dd if=/dev/zero of=/swapfile bs=1M count=4096
sudo chmod 600 /swapfile # set proper file protections
sudo mkswap /swapfile # init /swapfile
sudo swapon /swapfile # turn on swap
free -h # confirm 4G RAM and 4G swap
reboot # reboot and verify operation
Update #1:
Although the larger swap file helped, it didn't entirely fix the problem. User swapped out HDD for SSD, and it's all working ok now. Maybe some bad blocks on the HDD?
Update #2:
To bad block your old HDD...
Note: do NOT abort a bad block scan!
Note: do NOT bad block a SSD
Note: backup your important files FIRST!
Note: this will take many hours
Note: you may have a pending HDD failure
Boot to a Ubuntu Live DVD/USB in “Try Ubuntu” mode.
In terminal...
sudo fdisk -l # identify all "Linux Filesystem" partitions
sudo e2fsck -fcky /dev/sdXX # read-only test
or
sudo e2fsck -fccky /dev/sdXX # non-destructive read/write test (recommended)
The -k is important, because it saves the previous bad block table, and adds any new bad blocks to that table. Without -k, you loose all of the prior bad block information.
The -fccky parameter...
-f Force checking even if the file system seems clean.
-c This option causes e2fsck to use badblocks(8) program to do a
read-only scan of the device in order to find any bad blocks.
If any bad blocks are found, they are added to the bad block
inode to prevent them from being allocated to a file or direc‐
tory. If this option is specified twice, then the bad block
scan will be done using a non-destructive read-write test.
-k When combined with the -c option, any existing bad blocks in the
bad blocks list are preserved, and any new bad blocks found by
running badblocks(8) will be added to the existing bad blocks
list.
-y Assume an answer of `yes' to all questions; allows e2fsck to be
used non-interactively. This option may not be specified at the
same time as the -n or -p options.