Louwrentius

*** Desktop or Laptop ***

When deciding on which computer to buy, the first decision you have to make is about whether to go for a desktop or a laptop. There was a time that many believed that the desktop would become a niche product. Most people want a laptop because they can take their computer everywhere they want to. Or at least lie on the couch while surfing.

If you want a laptop that also must replace your desktop, it must have a good screen, be fast and have lots of storage. And laptops are so good these days, they can be desktop replacements. Even if you buy a small laptop, they can still be fast and when necessary, you just hook up an external display, mouse and keyboard.

This is how I worked for many years and I still do. But I consider switching back to a desktop-based computer.

*** Mac and PC ***

I have two computers. The first one is an Intel-based Macbook (black) mid-2007, which is my main computer. The second one is a custom-build PC running Windows, solely for the purpose of gaming. This PC is based on Intel's Core i7 920, with 6 GB of RAM, so it's quite fast, even for today standards.

Both Macbook and PC are connected to a DVI KVM switch, that allows me to switch the keyboard, video and mouse between those systems. They thus both share my EIZO 24" (1920x1200) screen, keyboard and mouse.

Apart from these systems, I own an iPhone and an iPad.

*** Replacing my Macbook ***

For the last half year, I started to get annoyed with my Macbook. It just got slow. I put in a faster hard drive, but to no avail. The Macbook wasn't responsive enough. So I started thinking about replacing my Macbook. The first thing I realised that I do not need a laptop. I have an iPhone and an iPad, so sending emails, reading web pages, no problem. I do not tend to work on my Macbook outside of my house. So I don't think I need the mobility of a laptop. I want a fast but quiet, affordable computer attached to a high-resolution screen.

If you are a Mac user, there are three options: an Mac mini, an iMac or a Mac pro. I consider the Mac mini to low on specs and the Mac pro is just way too expensive. That leaves the option of an iMac.

*** Going for an iMac ***

Since I love high-resolution displays, the iMac 27" does appeal to me very much. The screen is just gorgeous. And you can put an Intel Core i7 into it, so it can be fast too. Even the video card is decent enough to play most games, either on Mac OS X or on Windows using Bootcamp.

Then after a discussion with a friend, I realised that the iMac would replace my PC. And my EIZO screen. New iMacs will probably arrive this summer, sporting even better processors, video cards, probably Thunderbolt. So I think I've made up my mind. I would still have my 'old' Macbook if I really needed any mobility. But I expect that once I have an iMac, both my PC and my Macbook are better off in the hands of somebody else. And I will need the money, an iMac is not cheap.

Thinking about this all led me to believe that in general, I would rather go for a setup with an iMac and a very thin plus lightweight laptop like the Macbook Air, than to buy a chunky desktop-replacing laptop like a Macbook pro. The big advantage of the latter is that you always have all your stuff with you. But you pay a price. The first thing is the weight. I really dislike the weight of my Macbook at 2+ kilos. The second thing is the fact that you always have to (dis)connect all these cables every time you switch between "desktop mode" and "laptop mode". The third thing is the noise. When putting some strain on the processor and/or video card, laptops tend to get noisy.

A desktop can give you true performance while still keeping things quiet and provide you with ample screen real estate. A netbook-like device such as the Macbook Air can give you true portability. I won't buy a Macbook Air, but this would be a really nice setup. The only thing you need to fix is the syncing problem. But there are services like Dropbox that may help you with that.

*** Keeping my Macbook alive ***

My PC has an Intel X25-M Postville 160 GB SSD installed as a fast boot disk. Since I couldn't stand the unresponsiveness of my Macbook anymore, I decided to put this SSD into my Macbook. This is cheaper than buying a new mac and I want to wait for that until the new iMac models arrive.

Installing the SSD made my Macbook come alive again. The Macbook only sports a SATA 150 interface, but it's not about throughput. It's about random IO performance. I am very happy with the result, there is less of an urgent 'need' to replace the Macbook in the near future. I can wait calmly on the new iMacs and decide then what I want.

*** Other people's thoughts ***

There is also this podcast where John Gruber of Daring Fireball is telling about is his purchase of a Macbook Air and suggesting that he will replace his Macbook Pro 15" with an iMac eventually.

Many people have asked me why I do not use ZFS for my NAS storage box. This is a good question and I have multpile reasons why I do not use ZFS and probably never will.

** A lot has changed since this article was first published. I do now recommend using ZFS. I've also based my new 71 TiB NAS on ZFS. **

The demise of Solaris

ZFS is invented by Sun for the Solaris operating system. When I was building my NAS, the only full-featured and production-ready version of ZFS is implemented in Sun Solaris. The only usable version of Solaris was Open Solaris. I dismissed using Open Solaris because of the lack of hardware support and the small user base. This small user base is very important to me. More users is more testing. More support.

The FreeBSD implementation of ZFS became only stable in January 2010, 6 months after I build my NAS (summer 2009). So FreeBSD was not an option at that time.

I am glad that I didn't go for Open Solaris, as Suns new owner Oracle has killed this operating system in August 2010. Although ZFS is open source software, I think it is actually closed source already. The only open source version was through Open Solaris. That software is now killed. Oracle will close the source of ZFS just by not publishing the code of new features and updates. Only their proprietary closed source Solaris platform will obtain updates. But I must say that I don't have proof on this. However, Oracle seems to have at least no interest in open source software and almost seems to be hostile towards it.

FreeBSD and ZFS

So I build my NAS when basically ZFS was not around yet. But with FreeBSD as of today you can build a NAS based on ZFS right? Sure, you can do that. I had no choice back then but you do. But to be honest, I still would not use ZFS. As of March 1th, 2011, I would still go with Linux software RAID and XFS.

The reasons are maybe not that great, I just provide them for you. It's up for you to decide.

I sincerely do respect the FreeBSD community and platform, but it is not for me. It may be that I have just much more experience with Debian Linux and just don't like changing platforms. I find the installation process much more user friendly, I see a year over year improvement on Debian, I see none on the 8.2 FreeBSD release. Furthermore, I'm just thrilled with the really big APT repository. Last, I cannot oversee future requirements. But I'm sure that those requirements have a higher chance to support Linux than BSD.

Furthermore, although FreeBSD has a community, it is relatively small. Resources on Debian an Ubuntu are abundant. I consider Linux a safer bet, also on the part of hardware support. My NAS must be simple to build and rock stable. I don't want to have a day time job just getting my NAS to work and maintain it.

If you are experienced with FreeBSD, by all means, built a ZFS setup if you want. If you have to learn either BSD or Linux, I consider knowledge about Linux more valuable in the long run.

ZFS is a hype

This is the part where people may strongly disagree with me. I admire ZFS, but I consider it total overkill for home usage. I have seen many people talking about ZFS like Apple users about Apple products. It is a hype. Don't get me wrong. As a long-time Mac user I'm also mocking myself here. I get the impression that ZFS is regarded as the second coming of Jesus Christ. It solves problems that I didn't know of in the first place. The only thing it can't do is beat Chuck Norris. But it does vacuum your house if you ask it to.

As a side note, one of the things I do not like about ZFS is the terminology. It is just RAID 0, RAID 1, RAID 5 or 6 but no, the ZFS people had to use different, more cool sounding terms like RAID Z or something. But it is basically the same thing.

Okay, now back to the point: nobody at home needs ZFS. You may argue that nobody needs 18 TB of storage space at home, but that's another story. Running ZFS means using FreeBSD or an out-of-the-box NAS solution based on FreeBSD. And there aren't any other relevant options.

Now, lets take a look at the requirements of most NAS builders. They want as much storage that is possible at the lowest price possible. That's about it. Many people want to add additional disk drives as their demand for storage capacity increases. So people buy a solution with a capacity for say 10 drives and start out with 4 drives and add disks when they need it.

Linux allows you to 'grow' or 'expand' an array, just like most hardware RAID solutions. As far as I know, this is a feature is still not available in ZFS. Maybe this feature is not relevant in the enterprise world, but it is for most people who actually have to think about how they spend their money.

Furthermore, I don't understand Why I can run any RAID array with decent performance with maybe 512 MB of RAM while ZFS would just totally crash with so little memory installed. You seem to need at least 2 GB to prevent crashing your system. More is recommended if you want to prevent it from crashing under high load or something. I really can't wrap my mind about this. Honestly, I think this is insane.

ZFS does great things. Management is easy. Many features are cool. Snapshots, other stuff. But most features are just not required for a home setup. ZFS seems to solve a lot of 'scares' that I've only heard about since ZFS came along. Like the RAID 5/6 write hole. Where others just hookup a UPS in the first place (if you don't use a UPS on your NAS, you might as well also try and see if you are lucky running RAID 0) they find a solution that prevents data loss when power fails. One of the most interesting features to me is though that ZFS checksums all data and detects corruption. But I like it because it sounds useful, but how high are the chances that you need this stuff?

If ZFS would be available under Linux as a native option instead of through FUSE, I would probably consider using it if I would know in advance that I would not want to expand or grow my array in the future. But I am pessimistic about this scenario. It is not in Oracle's interest to change the license on ZFS in order to allow Linux to incorporate support for it in the kernel.

To build my 20 disk RAID array, I had to puzzle with my drives to keep all data while migrating to the new system. Some of the 20 disks came from my old NAS system, so I had to repeatedly grow the array and add disks, which I couldn't have done with ZFS.

Why I choose to build this setup.

The array is just a single 20 disk RAID 6 volume created with a single MDADM command. The second command I issued to make my array operational was to format this new 'virtual' disk with XFS, which just takes seconds. A UPS protects the systems against power failure and I'm happy with it for 1.5 years now. Never had any problems. Never had a disk failure... A single RAID 6 array is simple and fast. XFS is old but reliable. My whole setup is just this: extremely simple. I just love simple.

My array does not use LVM, so I cannot create snapshots or stuff like that. But I don't need it. I just want so much storage that I don't have to think about it. And I think most people just want some storage share with lots of space. In that case, you don't need LVM or stuff like that. Just an array with a file system on top of it. If you can grow the array and the file system, you're set for the future. Speaking about the future: please note that on Linux, XFS is the only file system that is capable of addressing more than 16 TB of data. EXT4 is still limited to 16 TB.

For the future, my hopes are that BTRFS will become a modern viable alternative to ZFS.

Intel and Apple released Thunderbolt a high-speed (10 Gigabit/s) interface, that seems to replace both USB and Firewire. It is mainly targeted at end-user systems allowing to connect peripherals with just a single cable to a computer. Thunderbolt devices, like external hard drives or displays can be daisy chained, like Firewire. In short, Thunderbolt removes the cable clutter and ads a significant speed bonus.

For NAS owners and storage enthusiasts, this is also a very interesting technology. Just like Firewire, it seems to support computer-to-computer communication. So Thunderbolt could be used as a high-speed link between your homegrown NAS device and your PC workstation. Or between two storage / server system.

The only downside to Thunderbolt is the maximum cable length of 3 meters between devices. Thunderbolt doesn't seem to be the ideal replacement for your Gigabit network, but if most of your computer systems are close to each other, it might be very interesting.