Logical Volume Manager (LVM) allows you to combine disks and create a single volume that can be mounted like a regular partition. It also allows you to add and remove storage. Make sure that you have the support for LVM compiled into your kernel. We set CONFIG_BLK_DEV_LVM=y on ours, and that worked well. [Note: Before […]

In this article, we set up Logical Volume Manager for GNU/Linux. We created a 12 GB device from 3 4 Gig drives, but only assigned 5 GB for our logical volume. Now, we are going to extend that volume. [Note: Before you do anything involving your partitions or volumes, make a complete backup. Make sure […]

In this article, and in this article, we showed how to install and extend logical volumes with LVM. Now, we want to shrink the filesystem we created and the logical volume, so we can remove the drive. [Note: Before you do anything involving your partitions or volumes, make a complete backup. Make sure to set […]

In this article, we freed up a disk from our volume so that we could reconfigure our system. In this article we will create and add a RAID1 device to our volume group. We removed /dev/sdg from our volume group, and /dev/sdh was unused, so let’s create a RAID1 device to add to our volume […]

So far, we have been using a generic 2.4.24 Linux kernel with LVM enabled. We had to compile this ourselves because the stock Red Hat / Fedora kernels don’t support our hard disks. See this article for more details. [Note: Before you do anything involving your partitions or volumes, make a complete backup. Make sure […]

In this article, we recompiled our software and kernel so we could remove our /dev/sde drive. [Note: Before you do anything involving your partitions or volumes, make a complete backup. Make sure to set up a test system with the same kernel and distribution to see how this stuff works. This article was written using […]

Agatha recently purchased another stick of 512MB RAM. It turns out that by default you need to change the kernel for it to use more than 1GB of RAM. Actually, the cutoff is technically at 960MB. Here is the memory info with 1.5GB of RAM installed, but with high memory support disabled: usr-1@srv-1 proc $ […]

There are 7 parts to this article: Part 1 – Gentoo on SPARC – Booting the Install CD Part 2 – Gentoo on SPARC – Creating the Filesystems Part 3 – Gentoo on SPARC – Copying Initial System, Portage, and Distfiles Part 4 – Gentoo on SPARC – Creating the Kernel Part 5 – Gentoo […]

There are 7 parts to this article: Part 1 – Gentoo on SPARC – Booting the Install CD Part 2 – Gentoo on SPARC – Creating the Filesystems Part 3 – Gentoo on SPARC – Copying Initial System, Portage, and Distfiles Part 4 – Gentoo on SPARC – Creating the Kernel Part 5 – Gentoo […]

There are 7 parts to this article: Part 1 – Gentoo on SPARC – Booting the Install CD Part 2 – Gentoo on SPARC – Creating the Filesystems Part 3 – Gentoo on SPARC – Copying Initial System, Portage, and Distfiles Part 4 – Gentoo on SPARC – Creating the Kernel Part 5 – Gentoo […]

There are 7 parts to this article: Part 1 – Gentoo on SPARC – Booting the Install CD Part 2 – Gentoo on SPARC – Creating the Filesystems Part 3 – Gentoo on SPARC – Copying Initial System, Portage, and Distfiles Part 4 – Gentoo on SPARC – Creating the Kernel Part 5 – Gentoo […]

There are 7 parts to this article: Part 1 – Gentoo on SPARC – Booting the Install CD Part 2 – Gentoo on SPARC – Creating the Filesystems Part 3 – Gentoo on SPARC – Copying Initial System, Portage, and Distfiles Part 4 – Gentoo on SPARC – Creating the Kernel Part 5 – Gentoo […]

There are 7 parts to this article: Part 1 – Gentoo on SPARC – Booting the Install CD Part 2 – Gentoo on SPARC – Creating the Filesystems Part 3 – Gentoo on SPARC – Copying Initial System, Portage, and Distfiles Part 4 – Gentoo on SPARC – Creating the Kernel Part 5 – Gentoo […]

There are 7 parts to this article: Part 1 – Gentoo on SPARC – Booting the Install CD Part 2 – Gentoo on SPARC – Creating the Filesystems Part 3 – Gentoo on SPARC – Copying Initial System, Portage, and Distfiles Part 4 – Gentoo on SPARC – Creating the Kernel Part 5 – Gentoo […]

We are running Gentoo on sparc64: srv-1 root # uname -a Linux srv-1 2.4.27-sparc #1 SMP Fri Dec 31 08:43:34 PST 2004 sparc64 sun4u TI UltraSparc II (BlackBird) GNU/Linux The first step in installing RAID 5 is to figure out what devices you have available: srv-1 root # dmesg | grep SCSI SCSI subsystem driver […]

We recently ran into an issue where there were legacy all-caps files in a directory, and we needed to move them. The remaining files were all lower-case. It turns out that when there are subdirectories involved, it is not as easy to move just the all-caps files, rather than the subdirectories. Here is an example […]

There are a lot of reasons to run GRUB. We feel there are also a lot of reasons to run LILO. If you do install LILO, the boot process will instantly become traditional. Red Hat hides much of the boot process by default, including the SELinux messages. Yes, sure, you could reconfigure it, but the […]

You can test for a particular user with the id test: [usr-1@srv-1 ~]$ if [ `id -u` = 0 ]; then echo root; fi [usr-1@srv-1 ~]$ su Password: [root@srv-1 usr-1]# if [ `id -u` = 0 ]; then echo root; fi root [root@srv-1 usr-1]# Here, we simply test for root, userid=0, and echo root if […]

One seemingly innocent question is, “what is the active memory statistic in top?”. That is, what does this mean: Mem: 508476k av, 456424k used, 52052k free, 0k shrd, 86780k buff 173524k active, 131488k inactive Swap: 2048276k av, 0k used, 2048276k free 218144k cached It is fine to understand why all of the memory is used […]

The power to our lab machines is controlled by a device we built in 2001. It uses the serial port to control a bank of relays. For more information on the device and how to build it, see this article. Now, it turns out that we often need to simply turn on all machines and […]