SSD RAID Build Options for IMS3000 Without Dolby Support

[Shibu Paul]

Dear All, I would like to know if there are any available options to build a RAID (preferably SSD-based) that is compatible with the Dolby IMS3000, without involving Dolby support or using the inbuilt IMS3000 RAID configuration tools. If anyone has experience or recommendations regarding external or third-party RAID configurations that work reliably with the IMS3000 system, please share your insights. Thank you in advance for your support.

[Marcel Birgelen]

I'm not sure if I'm the only one, but I don't really understand what the question is. Are you, maybe, looking for an external RAID based NAS solution that works with the IMS3000, but isn't necessarily on the supported equipment list of Dolby?

[Ryan Gallagher]

I'm not sure if I'm the only one, but I don't really understand what the question is. Are you, maybe, looking for an external RAID based NAS solution that works with the IMS3000, but isn't necessarily on the supported equipment list of Dolby?

That was my read too, although maybe with more inclination to DIY one out of a chassis and NAS distro.

[Shibu Paul]

We are currently planning to upgrade our Dolby IMS3000 server storage from 1TB to 2TB hard drives. However, we have observed that the RAID creation process within the IMS3000 takes approximately 8 to 10 hours, which impacts our operational downtime.

We would like to clarify whether there is any supported alternative method to create the RAID 5 configuration for the new hard drives outside the IMS3000 system, such as:

[Steve Guttag]

While full initialization can take some time, you should be able to ingest and use the server while it completes those tasks. It just slows the task down to a crawl while you are showing content. You can expect the ingest times to also be impacted while the RAID is initializing. If you had a spare IMS3000, you could initialize them in that, then transfer the drives.

[Marcel Birgelen]

If you know the EXACT initialization parameters, you probably could build the RAID on a separate Linux system with sufficiently free SATA or SAS ports. Still, there are so many unknowns that the chances of this ever going to work are pretty limited.

[Scott Norwood]

If you're using SSDs, it should not take 8-10 hours to constitute the RAID.

Insert standard rant about how RAID 5 really doesn't make much sense for this application and is unsafe when implemented in software.

[Steve Guttag]

What would you prefer to to RAID-5?

[Scott Norwood]

I'd probably just do a simple RAID 1 mirror. SSDs are big enough and fast enougn now that it would work fine, with less complexity and better write performance. This was not true in 2010 when everyone was using mechanical disks for everything.

[Ioannis Syrogiannis]

Big enough... Unless one works with a couple of features a week, I wouldn't call them that. The speed is a good thing, but it doesn't help much. Unless someone is considering ingesting while playing, and systems like IMS3000, of Dolby none the less, are not a great upgrade since previous models.
I would get storage capacity over speed whenever I could find it, but since 3-drives solutions and/or NAS became a norm and DSS200/DCP2K4/XCT-S10 became obsolete, good luck with that...

Edit: If I had the time and proper dock, I would initiate a RAID build on the server and finish it via mdadm command on a mutli-drive dock, while the IMS would still work with the old trio. I have done something similar with a software RAID in an older Doremi server.

[Leo Enticknap]

Agreed with Scott and Ioannis. $400 will buy you 2 x NAS grade 2TB SSDs to configure as a RAID1. For a multiplex SMS that typically plays the same show four times a day and with locally stored content managed by a TMS, that's more than enough. For an arthouse, screening room, or festival venue, it isn't.

Also agreed with Scott on the fragility of the combination of a software RAID and RAID5. It's not so bad on DolReMi, Barco, and recent GDC servers, because the operating system is stored on a totally separate flash drive (although they are not redundant, and as we have seen with the bad batch that was installed into early IMS3000s, that brings its own SPF risk); so a RAID drive failure will not make the server completely inoperable.

The most problematic software RAID5 implementation I've encountered is that of the DSS220 (software RAID5 of three drives). Basically, the only protection this arrangement is guaranteed to give you is that if one of the drives kicks the bucket, a show will not stop in the middle. In my experience, the odds are about 70/30 that you won't be able to get it to start rebuilding if you hot swap a failed drive, and/or that it will refuse to reboot again, leaving you with just a GRUB prompt. So you will likely have to do a clean reinstall of the operating system.

At a service contract site that has eight DSS220/cat745s still in service, I've worked around this vulnerability by leaving a spare set of drives on site, in cartridges (culled from a retired unit), configured as screen 99. If one of the in service DSS220s goes out and I can't get to the site quickly, I'll have the manager swap the spare set in, reboot the server, and then I'll configure it remotely for whatever screen went down, restore the serial automation settings from a file, and reingest whatever is needed from the TMS. There might be one lost show caused by the reingestion time, but that should be the limit of the lost business.

[Ryan Gallagher]

Agreed with Scott and Ioannis. $400 will buy you 2 x NAS grade 2TB SSDs to configure as a RAID1. For a multiplex SMS that typically plays the same show four times a day and with locally stored content managed by a TMS, that's more than enough. For an arthouse, screening room, or festival venue, it isn't.

4TB SSDs have been available at *some* price point since 2016, and we are up to 16TB ones now... seems doable as Raid 1 SSD even for rep/art-houses/festival houses. Whether those drives are supported by any servers is another topic.

Considering we still manage with a DCP2K4 with only 2TB raid5... our biggest festival either requires deleting as you go or a mid-festival purge. It all depends on how they schedule tech checks though if stuff has to stick around longer. For sure more storage would be "nice", but it's certainly doable on 2TB.

Our network ingest speeds are as good or better than CRU, so honestly even modest cinema server storage with a reasonable NAS seems pretty workable, and perhaps preferable to what we contend with now on busy weeks.

[Ioannis Syrogiannis]

[...]
Whether those drives are supported by any servers is another topic.
[...]

Well, the other way around...
It's just us derailing it. The topic is about a cinema server.

I would be more happy (capacity-wise) with a DCP2K4 or SV4, after adding the fourth disk, with 2TBx4 RAID5 than with any IMS. And its CRU port is a plus. But -alas- these days are counted.

[Leo Enticknap]

4TB SSDs have been available at *some* price point since 2016, and we are up to 16TB ones now... seems doable as Raid 1 SSD even for rep/art-houses/festival houses. Whether those drives are supported by any servers is another topic.

About a year ago, I did a service call to a post house, that I noticed had put 3 x Samsung 8TB SSDs into an IMS2000, which appeared to be working OK. Out of curiosity, when I got home, I looked up how much they cost: at the time, about $1,200 (they have come down quite a bit now). They could have bought the NAS for significantly less.

Agreed that it's theoretically possible to do a festival with only 2TB of SMS storage, but the logistical challenges, risks, and extra staff hour costs in pulling it off would seem to me to be not worth it given the cost of doubling the storage capacity. If you are constrained by 3 x 2.5" SATA slots, going above around 4TB of available storage in a RAID5 starts to invoke the law of diminishing returns, but up to that would be a no brainer, I'd have thought.