Warnings Regarding Email "cPanel 11.25 Tech Bulletin"

[rking]

We just received an email regarding potential disk space problems we might encounter when upgrading to cPanel 11.25. I've included the email in its entirety at the end of this post.

There are two major points I wanted to bring attention to.

1) Copying and Pasting the provide commands could RENDER YOUR SERVER UNUSABLE.

Due to the formatting in the email, the intended commands:

mkdir /home/bwtmp
tar -czvf /root/cp-bandwidth-backup.tar.gz /var/cpanel/bandwidth
mv /var/cpanel/bandwidth/* /home/bwtmp/
rm -rf /var/cpanel/bandwidth
ln -s /home/bwtmp /var/cpanel/bandwidth

when copied and pasted directly from the email have become this:

[ryan@testbox /]$ mkdir /home/bwtmp; tar -czvf /root/cp-bandwidth-backup.tar.gz /var/
[ryan@testbox /]$ cpanel/bandwidth ; mv /var/cpanel/bandwidth/* /home/bwtmp/; rm -rf /
[ryan@testbox /]$ var/cpanel/bandwidth ; ln -s /home/bwtmp /var/cpanel/bandwidth

Now, I make it a habit not to copy and paste commands directly from an email into an SSH shell, but the fact that rm -rf /var/cpanel/bandwidth was cut off to rm -rf / in the email immediately caught my eye.

2) Even running the commands as intended, you can fill up your / partition. Anyone using cPanel's old recommended partitioning scheme will probably have even less space on their / partition than their /var partition.

Running this command:

tar -czvf /root/cp-bandwidth-backup.tar.gz /var/cpanel/bandwidth

will likely fill your / partition.

Backing up is a great idea when doing any major server changes. I suggest modifying the command to create the tarball somewhere on /home.

tar -czvf /home/cp-bandwidth-backup.tar.gz /var/cpanel/bandwidth

Original Email:

You are receiving this communication because you are listed as the
admin contact for Acenet, Inc..

In cPanel 11.25 we have made a few feature improvements to the
bandwidth tracking system built into WHM and cPanel. While these new
features grants you a much more accurate and granular view of client
bandwidth usage, customers with inadequately sized /var partitions may
run into issues related to partition size and disk space consumption.

It should also be noted that the creation of these files occurs during
the first upcp that results in an upgrade to 11.25 and can require
significantly more time than normal upgrades.

The notice for this change was in our release notes for 11.25 which
can be found at http://docs.cpanel.net/twiki/pub/All...leasenotes.pdf

Change: Bandwidth graph RRD files are split off for each individual
service per domain and subdomain and stored in /var/cpanel/bandwidth/ .

Potential Issue: On some machines, depending on the partitioning
schema and the number of domains on a server, there may be a disk
space issue. This will only effect customers with large numbers of
domains and a relatively small /var/ partition, i.e., 8-10G. In these
situations, the /var/ partition may become full.

Workaround: For the time being, if you are affected by this issue, we
are suggesting the following temporary fixes.


Disabling Bandwidth Stats Generation: 'touch /etc/rrdtooldisable' .
This will disable generation of the rrdfiles altogether. Removing this
file will result in the graphs being generated again.

or

Symlinking /var/cpanel/bandwidth to a partition with more space.


The below command will create a /home/bwtemp directory, copy the
contents of /var/cpanel/bandwidth to it, create a backup in /root/cp-
bandwidth-backup.tar.gz, and then symlink the old directory to the new
one where there should be more diskspace.

'mkdir /home/bwtmp; tar -czvf /root/cp-bandwidth-backup.tar.gz /var/cpanel/bandwidth ; mv /var/cpanel/bandwidth/* /home/bwtmp/; rm -rf /var/cpanel/bandwidth ; ln -s /home/bwtmp /var/cpanel/bandwidth'

If you have issues executing the fix for this change, please submit a
ticket via https://tickets.cpanel.net and we will assist you with this
fix.
---------------------

[rking]

This image may illustrate what I'm talking about a little better. Perhaps the email comes out properly in other mail clients, but Thunderbird presented it like this:

[cpanelkenneth]

This was addressed in a followup advisory sent October 12, 2009.