One of my DSS200s is constantly verifying the RAID State

[Leo Enticknap]

Dolby's official line was just to kill the power to it, but it goes against everything I've ever been taught about computers in general not to do a formal shutdown procedure first.

My suggestion would be to shut down the server side, by pushing ctrl+alt+F1 (on a keyboard connected directly to the DSS200), and then, when you see the login prompt, ctrl+alt+del. The Linux shutdown procedure will then execute, after which the computer will reboot. There is a Dolby logo that appears during the start of the POST sequence: I would suggest actually flipping the breaker while that is visible, and therefore no hard drive activity is in progress.

[Nathan Paris]

I've always found it odd that we just shut them off by switch and then breaker, but since I was taught that I went with it until I started to understand more about the equipment. I'm leaning more towards changing things and leaving our DSS200s online constantly going forward after this Theater 1 scare (hoping it's just the RAID and not the media block), but if we continue to shut them down then I'll do that process.

Thanks, Leo!

[Marcel Birgelen]

Dolby's official line was just to kill the power to it, but it goes against everything I've ever been taught about computers in general not to do a formal shutdown procedure first.

The fact that they hid the power button behind the front bezel for me is a clear indication they also designed this thing to be "always on". The story that you can just unplug the power, is a bad one. You're leaving filesystems dirty and you're also triggering a RAID verification, which only adds unnecessary extra stress on the disks.

I think leaving them on from now on is the more prudent way to go forward. Maybe this also solves the "stuck in verification forever" mode. The verification can take quite a while...

[Leo Enticknap]

Agreed completely. My point was simply that if Nathan does decide to continue shutting his DSS200s down overnight, the ctrl+alt+F1 > ctrl+alt+del method is preferable to simply pulling the plug while a server is fully booted and Show Manager is running.

[Steve Guttag]

Ryan,

The different luminance is not FPS related, it is related to color correction associated with 3D and, in particular, Dolby 3D, where each eye is given a different color correction due to how the whole Dolby 3D system works. You will have different effective luminances between the two eyes. The final step after color correction is to lower the brighter eye to match the darker one. You then set the final luminance level and both eyes should match.

One does not color correct on an FPS basis. One does set filter wheel sync on an FPS basis because...it is like timing a shutter where the frame rate is different AND the flash rate is different. That is, for 24fps, you have "triple-flash" to get 72-flashes per eye or 144 flashes total. For 48fps, you normally use double-flash for 96 flashes per eye and 192 flashes by the ICP (pretty much its limit). For 60fps you go with single flash per eye or 120 flashes per frame. I think the problem comes with a system that has 30fps and 60fps though there is a possibility of 2.5 flashes per eye (5:2) to get to 75Hz, which would mess with those people that work with 25fps content. The Dolby DFC100 only understands 48, 60, 72, 75 and 96Hz. So, one has to pick within those frequencies (total flashes per eye). You have to pick which frame rates will get the sync setting. With Barco, you can have specific 3D settings for each permutation.

It's just about moot now as 3D's popularity has just about vanished (except for a couple of directors and specific titles, like Avatar) and the frame rates they are going for is, begrudgingly, 24fps as an accommodation rate and over 100fps as preferred despite few systems being capable and zero proven consumer demand.

This is what a DFC100 UI looks like for setting the filter wheel (disengaged in this screen shot):

image.png

All it has to go by is the pulse it gets from the projector's GPIO or 3D port.

There are other 3D specific settings, like dark time (how long between eye flashes) and just like a film shutter to prevent the wrong eye's image going through the wrong filter wheel.

[Ryan Gallagher]

Not having used a DSS200... but does it trigger a clean shutdown if you hold the power button like some hardware does? If not then yeah some software method best to shutdown or reboot (and interrupt as Leo suggests). Asking people to ssh over to it just to shutdown feels excessive, even if credentials were known.

[Marco Giustini]

There is no power button on the DSS series
The only way to do a clean shutdown is to issue a shutdown command via terminal

It was "designed" to deal with that. I don't like it but it is what it is. Like the XD10

[Marcel Birgelen]

There is a "power button" behind the front bezel, but you need something like a paperclip to press it. If I remember correctly, it works like a traditional ATX power button: short press will send a shutdown command to the power controller, the OS will intercept it and perform a "clean shutdown", press it more than 4 seconds and the system will cut the power to the main busses immediately, leaving only the standby busses operational.

[Steve Guttag]

Yeah know...if I had DSS200 issues due to its abrupt shutdown...after what 15-16 years, I'd understand your concerns. But I don't. Most of my systems run their servers 24/7 anyway. However those that just run weekends, they do shut down...I don't see any increase in issues on those...in fact, possibly fewer issues...probably because they use them less.

Barco's ICMP series also has to contend with abrupt shutdowns...no real problems there.

The IMS1000 is legendary for its corruption on abrupt power offs. The IMS2000 takes it up to a point but the OS SSD will absolutely go corrupt as will the IMS3000. You won't find GDC sanctioning abrupt power downs.

In my IMS/SR-1000 systems, we have the automation (eCNA) handle the shutdowns...it issues the shutdown command to the server...waits 1-2 minutes for it to fully shutdown and "park" the drives and then kills power to the projector. It is unsatisfying to the closing manager since it appears that nothing is happening after they press the switch. In theatres where we control the sound too...at least they get the "clack" of the amps going into standby.

[Ryan Gallagher]

It is unsatisfying to the closing manager since it appears that nothing is happening after they press the switch. In theatres where we control the sound too...at least they get the "clack" of the amps going into standby.

Hehe, Need a big rotating beacon light that stays active until the shutdown sequence is complete. ;-)

[Caleb Williams]

Dolby's official line was just to kill the power to it, but it goes against everything I've ever been taught about computers in general not to do a formal shutdown procedure first.

From a software/OS perspective, the DSS line of servers are designed using an overlay file system with read-only components. The base system and the cinema software reside on two separate partitions that are combined in an overlay during the boot process, then a third and fourth partition hold the database and the dcp assets, and are read+write. The RAID 5 protects the entire system (aside from the bootloader, which is a non-volatile IDE memory component) and the entire configuration is extremely resilient against sudden power loss. Thus, as we have experienced, most of the critical failures were of the media blocks.

The Sr-1000 and IMS servers do not have a similar system. The bootloader, os, and some database components all live on a single flash card or ssd and are a single point of failure. The SR-1000 runs on a raspberry pi with an industrial grade sd-card. IMS servers use the equivalent of a thumb drive on a USB header. While both do mark the base system partition as read-only, that only prevents accidental config changes, and is actually more of a hassle than a benefit. Flash data storage has come a long way with wear leveling and stability since the DSS line, but having that single point of failure has caused us many a headache. I miss the reliability of the DSS platform in that respect.

[Caleb Williams]

Yeah know...if I had DSS200 issues due to its abrupt shutdown...after what 15-16 years, I'd understand your concerns. But I don't. Most of my systems run their servers 24/7 anyway. However those that just run weekends, they do shut down...I don't see any increase in issues on those...in fact, possibly fewer issues...probably because they use them less.

Barco's ICMP series also has to contend with abrupt shutdowns...no real problems there.

The IMS1000 is legendary for its corruption on abrupt power offs. The IMS2000 takes it up to a point but the OS SSD will absolutely go corrupt as will the IMS3000. You won't find GDC sanctioning abrupt power downs.

In my IMS/SR-1000 systems, we have the automation (eCNA) handle the shutdowns...it issues the shutdown command to the server...waits 1-2 minutes for it to fully shutdown and "park" the drives and then kills power to the projector. It is unsatisfying to the closing manager since it appears that nothing is happening after they press the switch. In theatres where we control the sound too...at least they get the "clack" of the amps going into standby.

I'm not super familiar with the eCNA. Is it possible to completely automate this so they don't have to manually trigger a shutdown? Then they don't have to experience the disappointment of "nothing happening" lol

[Marco Giustini]

aside from the bootloader, which is a non-volatile IDE memory component

If you mean the little IDE flash drive plugged directly into the IDE on the MB, that was made redundant at some point, you can just unplug it, the whole system is on the RAID. (whether you need to reinstall at that point I'm not sure but I know it's not required anymore)

[Steve Guttag]

I'm not super familiar with the eCNA. Is it possible to completely automate this so they don't have to manually trigger a shutdown? Then they don't have to experience the disappointment of "nothing happening" lol

It is. You can set it to turn on/off the system based on a rigid time policy (and you can do that by days of the week. If the POS vendor can export a "BLODE" type file, then Eprad makes a "Nanohost" that can use the actual schedule to have the automations turn the systems on/off as well as keep the xenon lamps off unless tickets are sold for a performance. We've also had it work with Q-SYS to determine if content is transferring and prevent a shutdown until content has finished transferring.

[Ioannis Syrogiannis]

There is no power button on the DSS series
The only way to do a clean shutdown is to issue a shutdown command via terminal
[...]

The "shutdown" command is missing from the /sbin/ directory, though. At least it did, last time I checked. I assume it was deliberately removed from there.