If I use the Pi a bit, filesystem corruption soon appears.
For instance, this file was changed to another one:
$ ls -alt /etc/apt/apt.conf.d total 16 lrwxrwxrwx 1 root root 13 Oct 2 22:18 50raspi -> ../init.d/ntp
/var/lib/dpkg/info/fake-hwclock.list became a binary file, which
means dpkg can no longer work:
dpkg: unrecoverable fatal error, aborting: files list file for package 'fake-hwclock' is missing final newline E: Sub-process /usr/bin/dpkg returned an error code (2)
fsck on the filesystem finds many mistakes and send dozens of files to
Pass 1D: Reconciling multiply-claimed blocks (There are 34 inodes containing multiply-claimed blocks.) File /etc/fake-hwclock.data (inode #26, mod time Thu Aug 16 02:20:47 2012) has 1 multiply-claimed block(s), shared with 1 file(s): ... (inode #30, mod time Thu Aug 16 02:20:47 2012) ... Inode 30 ref count is 1, should be 3. Fix? yes
dmesg displays what looks like I/O errors:
[ 49.082758] mmc0: final write to SD card still running [ 59.088233] mmc0: Timeout waiting for hardware interrupt - cmd12. [ 59.089411] mmcblk0: error -110 sending stop command, original cmd response 0x900, card status 0x900
I tried with four different SD cards, of makes SanDisk SDHC 16 GB and Duracell SDHC 16 GB. So, it does not seem to be the card.
I also tried with Raspbian 2012-08-16-wheezy and ArchLinux 13-06-2012. Both have the same problem so I assume it is not a bug in the OS.
Following advices by @gnibbler and @Avio, i ran memtester (which, unlike memtest86 on the PC, runs after the kernel and therefore cannot test all the RAM) and it reported no problem. "memtester 200 2" -> everything OK
Following the discussion in http://www.raspberrypi.org/phpBB3/viewtopic.php?f=29&t=6201&start=400 , I tried from a new image with a config.txt written for a little underclocking:
core_freq 240 arm_freq 650 sdram_freq 350
but it made the problem worse (a lot of timeouts on the card)
I have only one Raspberry Pi so I cannot check with another. Known problem? Broken hardware?