# Gibibytes and Tebibytes

After almost 6 years with my Core 2 Duo E6600, I'm seriously thinking about a replacement. I already have a pretty clear idea of most components, but I am still ambivalent about a few of them, particularly, the mass storage.

In terms of performance, the magnetic hard drives (HD) commonly used for mass storage are the bottleneck in today's computing. Booting the system, starting applications or reading/writing large files, running a sync or a backup: all of these everyday situations are usually limited by disk speed, not the processor or memory.

You can monitor the disk access by iotop, and limit it by ionice. Or you can buy a solid-state drive (SSD). These little miracles are usually much more responsive, but also more expensive than their mechanical counterparts. People thus commonly use a small SSD for the system and a large HD for their data. But how large and fast an SSD and how large an HD do I need for this strategy? And do I need the latter at all?

To answer these questions, I need an idea of my current storage use and my potential future requirements. I have partitioned my HD such as to simulate a system residing on a 60 GB SSD, and my home on a 230 GB HD. I have also generously installed all packages which could be of even the slightest interest for me, including all first-person shooters available on the ArchLinux repositories. ;)

[cobra@blackvelvet ~]\$ df -h
Filesystem          Size    Used    Avail   Use%    Mounted on
/dev/sda1           130M    21M     103M    17%     /boot
/dev/sda3           63G 21G 39G 35% /
/dev/sda4           227G    106G    110G    49% /home


Despite having installed essentially all I can think of, the system only occupies 21 GB. Apparently, I will have no difficulties to find an SSD on which my system fits very comfortably. (My Windows 7 installation at work, in contrast, requires 27 GB after installing Origin, MS Word and Powerpoint. 27 GB, and rising ... :O )

But what about the ridiculous 106 GB in my /home? Is that all? Well, it could actually be even much less, since more than 60 GB are virtual machines. And what else should I store there anyway? All multimedia content resides on the NAS. Current projects are synchronized between all of my machines using Wuala, but that rarely occupies more than 1 GB. Completed projects are archived and always accessible via an ssh connection to my office machine, and thus don't need to be stored at my home in addition.

In principle, a single 240 GB SSD would be more than sufficient to hold both the system and my data. But that feels like a rather radical solution to me. Right now, I tend to a dual SSD configuration, but also that's still subject to change. ;)