A backup script that runs on several Linux systems recently produced the following error:
ls: cannot access '/tmp/sortrq9hq8': No such file or directory
It happens every time the backup runs. Other than the above message, there seems to be no ill effect on the backup, which completes successfully. The ls command did not find a file that it expected to be there.
This article explains how the missing file was created by the Linux sort command as a temporary storage area, how error messages about these files are likely to crop up from time to time, how to reproduce the error, and some background about the behaviour of the sort command on Linux and Solaris. Continue reading →
“Dirty Cow” is the common name given to Linux vulnerability CVE-2016-5195. It is a “privilege escalation” that allows a non-root user to gain root access on a system. An attacker must have system access first, as a normal user. Then they use the bug to obtain root rights. It is dangerous and should be patched.
The Linux kernel itself was fixed in October 2016. Since then, Linux vendors have all released patches. Many Internet articles suggest addressing the bug by doing a general system update. While that might be fine for a test machine or Linux desktop, it isn’t ideal for a production server. This article describes how to fix the bug in the least invasive way possible – by updating the kernel only. Continue reading →
Debian 8 (jessie) was released in April 2015, ten months ago at the time of writing. Some sites will have upgraded by now, and others might be considering the move. This article provides a list of issues encountered after upgrading several servers from Debian 7 (wheezy) to Debian 8. These are system administration issues in the most part, though some might also be of interest to application support staff. Continue reading →
The Raspberry Pi is a small Linux computer designed to help children learn programming. Being a full Linux System, it can also be used as a server or as the basis for various projects.
Here are some adjustments you might want to make to a new Raspberry Pi. The examples refer to a Raspberry Pi Model “B” bought from UK distributors New IT in February 2013. But they are pretty universal. Continue reading →
The Sheevaplug is is a very small computer made by Globalscale. It is designed to offer standard computing functions in a very small space. Consuming just a few watts of power, the Sheevaplug makes a good home server, with applications ranging from network storage to web hosting and home security.
This article explains how to upgrade a Sheevaplug to Debian 6 using a pre-built image available from New IT. It is a quick and simple procedure, requiring less technical knowledge than, for example, installing Debian from scratch. Continue reading →