We’ve received reports from two users on two distinct physical hosts about severe file corruption after they upgraded to Debian Buster. For one of them, the filesystem corruption showed up approximately a week after the upgrade. For another it was several weeks.

These specific users were running an older file system called ext3, but we’re still gathering data to attempt to isolate the issue. Right now we think it may be related to the latest Debian kernel version 4.19.118+2+deb10u1 and the Xen hypervisor, or it may be specific to ext3.

We believe that if the problem is specific to Xen, linux-image-4.19.0-8-amd64/4.19.98-1 should be safe. This is the version present in our current image for Debian Buster.

This article offers some information about what to do if you are using an EXT3 filesystem, have installed Buster, or are considering either of these choices.

For customers currently running Buster, please take note of the “Information Wanted” section.

Regardless of your choice of distribution, if you are using EXT3, you might want to consider migrating your filesystem to EXT4. EXT3 is quite old, and incompatibility issues are more likely to occur using it.

Planning to install Buster?

Before installing, please do the following.

Check your file system

Check to see if your filesystem is ext3. Use the command:

$ df -T

Sample Output:

Filesystem Type 1K-blocks Used Available Use% Mounted on
udev   devtmpfs   15080720   1508072   0% /dev
tmpfs  tmpfs   306488 1072305416   1% /run
**/dev/sda1  ext4  20509264 17468740   1975668  90% /**

Check the “Type” column for the filesystem that shows “/” in the “Mounted ON” column. The corresponding line is bolded in the above sample. In this case, the filesystem is ext4.

Not EXT3?

If your filesystem type shows as EXT4, ZFS, or any other filesystem that isn’t EXT3, you can continue installing Buster.

If you have ext3, upgrade to ext4

It is strongly suggested that you switch to ext4 before upgrading to Buster. Follow this procedure:

https://debian-administration.org/article/643/Migrating_a_live_system_from_ext3_to_ext4_filesystem

Post-update or install changes

To downgrade your kernel, the following procedure should suffice. You should reboot immediately once it is complete.

sudo apt-get install linux-image-4.19.0-8-amd64
sudo apt-get remove linux-image-4.19.0-9-amd64

Select “no” when the package manager asks if you would like to abort removal of the running kernel.

Once you have downgraded and performed a reboot, verify with:

uname -a |grep '4\.19\.0-8'

Information Wanted

If you already have Buster installed, we would greatly appreciate your assistance in tracking down when this bug occurs. We would like to know your kernel version and some filesystem metadata. Please run the following commands:

df -T > busterdata
uname -r >> busterdata
uptime >> busterdata
/sbin/ip -4 addr list eth0 >> busterdata

Send it to us.

Send the output file to support@prgmr.com, with your host name and “Buster Data” in the subject line.

And of course, if you have any problems with a Buster installation or anything else, let us know.