Film-Tech Forum ARCHIVE: Dolby DSL200 uses 8TB hard disk

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Posted by Tacky Ting (Member # 8686) on 10-03-2018, 06:35 AM:

Hello, everyone
Have you ever tried to replace the Dolby DSL200 with 8 Toshiba Enterprise 8TB MG05ACA800E SATA3 /128MB HDD?

Posted by Dave Macaulay (Member # 813) on 10-03-2018, 06:53 AM:

Well, no.
There may be 8 drive bays but I think only 4 have drive connections, the rest are unusable.
8TB drives may work, I don't know. They are not tested or approved. Let us know.
Why do you need that much storage?

Posted by Ioannis Syrogiannis (Member # 3235) on 10-03-2018, 07:01 AM:

Dave, I think that the DSL libraries (as opposed to DSS) have the connectivity for 8 drives.

Tacky, even though dolby did qualified a number of the Toshiba MG04ACA series HDDs, the MG05ACA seems to be a series that support 8TB.
If I was to experiment, I would probably play it safe and go for the 5TB MG04ACA series (MG04ACA500E).
But, then again, I am not so much of an experiment-driven guy... so I 'll wait for your feedback.

Posted by Brad Miller (Member # 2) on 10-03-2018, 10:32 AM:

You can swap the raid card out for a model 9650SE-8LPML which will permit all 8 bays to work.

Posted by Leo Enticknap (Member # 534) on 10-03-2018, 02:23 PM:

Why would you want to put around 50TB of storage capacity in a DSS200 (8 x 8TB drives in a RAID5 configuration)? OK, a DSS200 can be used as a mini TMS for, if memory serves me correctly, three or four screen servers, but even that wouldn't need anything approaching that capacity. The biggest TMS I've ever encountered had 24TB of usable capacity, and that was in a unique situation (a post house that had to deal with a huge amount of content).

In 2014, I followed Brad's suggestion and installed the 8-port 3Ware RAID card plus 8 x 2TB drives into one, but in those days the cost of bigger drives was such that this was the most cost effective way to buy 13TB of usable capacity; and the big festivals we were doing, some of them back-to-back, meant that we needed that. Not any more, though: if I were in the same situation now, I'd use 4 x 4TB.

Posted by Mike Renlund (Member # 4675) on 10-03-2018, 03:35 PM:

FYI, you cannot make a partition larger than 16TB on DSS servers. The Linux OS that was used does not support anything bigger than that.

Posted by Steve Guttag (Member # 268) on 10-03-2018, 07:33 PM:

Note, the OP did state DSL200 so it should have the necessary RAID already. It will configure as RAID6 though. I believe you can load all 8 bays to take advantage of the storage but the UI will only show the first 6.

Posted by Mike Renlund (Member # 4675) on 10-03-2018, 08:11 PM:

My apologies. DSS or DSL devices cannot exceed 16TB for the partition size. It is the same Linux kernel on both devices.

Posted by Leo Enticknap (Member # 534) on 10-03-2018, 08:29 PM:

I didn't notice the L, either - sorry.

From what I can see looking inside them, the differences between the DSS200 and the DSL200 are that the DSL has a different model of RAID card (3Ware 9750-8i, which has a backup battery on it) and no cat862 media block in it: otherwise, they're the same machine.

If you use the optional SAS card on a DSL200, you can boost the total space available beyond 16TB, but only because you're then using two separate filesystems (the onboard content RAID and the external one).

Still, 50TB on a single TMS? I suppose if you're running a 30-plex, with all the screens playing 3-hour long, 4K, HFR features, you'd be approaching that sort of capacity requirement, but not unless.

Posted by Adam Martin (Member # 641) on 10-03-2018, 09:37 PM:

You'd be surprised at how quickly TMS space gets used up when you deal with 2D, 3D, 6fl 3D, Laser 3D, Atmos, Auro, DTS-X, Dolby Vision, and IMAX.

And then add in the 17,238 trailers for [pick a tentpole] with a different version of each of those trailers for every 3D and "PLF" format out there, plus some chains get preferential branding and those get sent out to everyone.

If you have DCDC, you can expect today to have this week's titles, next week's titles, and later tonight they'll start to delivery the following week's titles.

Sometimes you get both Interop and SMPTE versions of a title, and you can't delete one because who know what keys they'll send next week.

Don't get me started on special events, promo screenings, or classic film series!

Posted by Ioannis Syrogiannis (Member # 3235) on 10-04-2018, 03:36 PM:

quote: Mike Renlund
DSS or DSL devices cannot exceed 16TB for the partition size. It is the same Linux kernel on both devices.

Could that be arranged if the page size could be set during creating the XFS partition?

In any case, that's nice to know and I 'd be happy to see dolby pointing the limitation fact on the "dolby cinema server qualified hard drive list" under DSL200, so that no-one gets to use bigger than 3TB ones for 8 disk RAID arrays, since that would be of no use.

Posted by Mike Renlund (Member # 4675) on 10-04-2018, 03:54 PM:

Thanks Ioannis, it is a great idea to add that piece of information to the Hard Drive list. It applies to both any DSS or DSL and so I have placed it in a more general location, but changed the color so that it jumps out at you. I've uploaded the new version to www.dolbycustomer.com.

Posted by Tacky Ting (Member # 8686) on 10-05-2018, 05:21 AM:

Does max 16TB for the partition size, including the two Barkup Hard disk capacities of RAID 6?
I use 6 X 4TB Toshiba MG04ACA400E , can I?

Posted by Leo Enticknap (Member # 534) on 10-05-2018, 05:32 AM:

I don't know for sure - Mike or someone would have to advise - but my guess would be yes. The RAID6 redundancy is handled by the RAID card in hardware, and the limitation we're talking about is in the Linux filesystem. The operating system therefore "sees" the RAID as a single volume, of whatever capacity the RAID controller reports it to be to the operating system, up to 16TB. So if you put 6 x 4TB drives in, giving you 24TB of raw capacity, that will come down to around 16 if they are configured as a RAID6 volume. The RAID card will tell the operating system that it has a 16TB volume attached, and you should - in theory - be all set.

Posted by Steve Guttag (Member # 268) on 10-05-2018, 07:17 AM:

I'm reasonably certain that you can load six 4TB drives in a DSL200 and get a 16TB RAID 6 system (and it won't be 16TB due to the RAID).

I have one 3-plex that does subrun and they have all three servers with 4TB drives so they have essentially 36TB for the complex to harvest up to 15-weeks of movies and previews from DCDC such that they have the content when it makes it to subrun. Often, they don't know what they are going to run 15-weeks in advance so it is easier to get everything and dump what you don't need once you know what you are going to book. Having that large capacity makes it easier.