Louwrentius

I don't have a TV. I haven't been watching TV for more than 10 years. But I love to watch movies or great series like Dexter and Game of Thrones. Until recently, I watched movies or series on my 27" iMac. Twenty-seven inch is large for a computer screen but for a TV, it's quite small.

When it comes to watching movies, a bigger screen is always better. The big screen of a movie theater is the most important reason for movie enthousiasts to experience a movie in the theatre. But there is a way to get that movie theatre feel into your living room: get a digital projector. That's what I did.

I decided to get a ceiling mounted projection screen that I could lower just in front of my computer and table. I chose the "celexon Rollo Economy with a dimension of 277 x 156 cm (109 x 61 inch). This would give me a TV screen with a theoretical size of 125 inch in diameter! In practice, the actual projected image is around 120 inch.

Just think about that. A 120 inch television. Hundred-and-twenty inch. Three metres diagonal.

The screen can be lowered by just pulling on the edge. I have to reach for it on my toes but it's ok. As pictured below, the screen has an additional black area so it can be lowered further away from the ceiling. This way, the effect of the ceiling reflecting light back to the screen, reducing picture quality, is reduced. It allows you to have the screen at the desired hight, you don't need to look up.

At the other end of the room, I decided to mount a projector on a ceiling mount. My iMac would sent all digital content through a long HDMI cable to the projector.

After doing some research I decided to buy the Panasonic PT-AT5000E also known as the PT-AE7000. This digital projector supports Full HD 1080p at 1920x1080. It also supports 3D but I'm not really interested in that.

I have never seen a movie on a digital projector before and I can't compare it to other digital projectors. But one thing is sure. Watching a 1080p movie on a 120" display projected by this digital projector is quite an experience. To me the picture is astounding. It is almost if you are in a theatre. A digital projector may not always be practical, but it is surely awesome.

I do have some remarks about the whole setup with a digital projector:

1. you need a big screen and mount it somewhere;
2. the projector is just gigantic and you must accept that it hangs from your ceiling somewhere, something your spouse may not like;
3. you need to run some extra cables for power and HDMI through your house;
4. you need to put the lens cap on when the device is not in use, often a hassle;
5. the lamp takes several minutes to reach optimal operational temperature;
6. although my panasonic projector is almost silent, it does make noise;
7. you must have good curtains to block all external light or you won't see a thing;
8. you need to wait for movies to be released on Blu-ray or the Internet to be able to watch them;
9. the lamp will wear out and replacements are expensive;
10. if anyone would ask you about the size of your TV you would have to lie or feel a douchebag for telling the truth.
11. Non-HD content looks totally crap and you need to make the picture smaller just to stand it.
12. the whole home theatre setup is just expensive and you could have bought a lot of theatre tickets for that money;
13. black levels are often not as good as plasma TV's.

But in the end I would not hesitate to fork out the money for a home theatre setup like this. Because of the downside of movie theatres:

1. other people. They are the cause that you don't have the best seat in front of the screen;
2. more other people, who text, talk or phone during the movie;
3. even more other people, who eat crappy food, making noise and drink crappy liquids as if it where a slurping contest;
4. you need to pay money;
5. you need to sit in some crappy movie theatre chair;
6. you must pay top dollar for a drink or food;
7. no pauses so no toilet breaks;
8. you need to go there, and be there at a specific time;
9. you need to stand many commercials before the movie actually starts;
10. the sound quality is often horrible.

So in my opinion, if you you are willing to spend money on it, I would advice to seriously look into getting a digital projector.

I really like ZFS because with current data sets, I do believe that data corruption may start becoming an issue. The thing is that the license under which ZFS is released does not permit it to be used in the Linux kernel. That's quite unfortunate, but there is hope. There is a project called 'ZFS on Linux' which provides ZFS support through a kernel module, circumventing any license issues.

But as ZFS is a true next generation file system and the only one in its class stable enough for production use, I decided to give it a try.

I used my existing download server running Ubuntu 12.04 LTS. I followed these steps:

1. move all data to my big storage nas;
2. destroy the existing MDADM RAID arrays;
3. recreate a new storage array through ZFS;
4. move all data back to the new storage array.

Installation of ZFS is straight forward and well documented by the ZFSonLinux project. The main thing is how you setup your storage. My download server has six 500 GB disks and four 2 TB disks, thus a total of ten drives. So I decided to create a single zpool (logical volume) consisting of two vdevs (arrays). I thus created a vdev of 6 500 GB drives and a second vdev of the four 2 TB drives.

root@server:~# zpool status
  pool: zpool
 state: ONLINE
 scan: scrub repaired 0 in 1h12m with 0 errors on Fri Sep  7 
config:

    NAME                               STATE   READ WRITE CKSUM
    zpool                              ONLINE     0     0     0
      raidz1-0                         ONLINE     0     0     0
        pci-0000:03:04.0-scsi-0:0:1:0  ONLINE     0     0     0
        pci-0000:03:04.0-scsi-0:0:2:0  ONLINE     0     0     0
        pci-0000:03:04.0-scsi-0:0:3:0  ONLINE     0     0     0
        pci-0000:03:04.0-scsi-0:0:4:0  ONLINE     0     0     0
      raidz1-1                         ONLINE     0     0     0
        pci-0000:00:1f.2-scsi-2:0:0:0  ONLINE     0     0     0
        pci-0000:00:1f.2-scsi-3:0:0:0  ONLINE     0     0     0
        pci-0000:03:04.0-scsi-0:0:0:0  ONLINE     0     0     0
        pci-0000:03:04.0-scsi-0:0:5:0  ONLINE     0     0     0
        pci-0000:03:04.0-scsi-0:0:6:0  ONLINE     0     0     0
        pci-0000:03:04.0-scsi-0:0:7:0  ONLINE     0     0     0

So the zpool consists of two vdevs that each consist of the physical drives.

Everything is going smooth so far. I did have one issue though. I decided to remove a separate disk drive from the system that was no longer needed. As I initially setup the arrays based on device names (/dev/sda, /dev/sdb), the array broke as device names changed due to the missing drive.

So I repared that by issuing these commands:

zpool export zpool
zpool import zpool -d /dev/disk/by-path/

It's important to carefully read the FAQ of ZFS on Linux and understand that you should not use regular device names like /dev/sda for your ZFS array. It is recommended to use /dev/disk/by-path/ or /dev/disk/zpool/ exactly to prevent the issue I had with the disappeared drive.

As discussed in my blog entry on why I decided not to use ZFS for my big 18 TB storage NAS, ZFS does not support 'growing' of an array as Linux software RAID does.

As the zpool consists of different hard disk types, performance tests are not consistent. I've seen 450 MB/s read speeds on the zpool, which is more than sufficient for me.

ZFS on Linux works, is fast enough and easy to setup. If I would have setup my big storage NAS today, I would probably have chosen ZFS on Linux by now. I would have accepted that I could not just expand the array with extra drives the way MDADM permits you to grow an array.

In some way, ZFS on Linux is combining the best of both world. One of the best modern file systems with a modern and well-supported Linux distribution. Only the ZFS module itself may be the weak factor as it's fairly new for Linux and not optimised yet.

Or we might have to just wait until BTFS is mature enough for production use.