Film-Tech Forum ARCHIVE: DSS-200 Degraded Array Question

my profile | my password | search | faq & rules | forum home

»	Film-Tech Forum ARCHIVE » Operations » Digital Cinema Forum » DSS-200 Degraded Array Question (Page 3)

This topic comprises 3 pages: 1 2 3

Author

Topic: DSS-200 Degraded Array Question

Mark Gulbrandsen
Resident Trollmaster

Posts: 16657
From: Music City
Registered: Jun 99

posted 07-27-2019 10:33 AM

quote: Scott Norwood
It is hard to find conclusive data on this, but mechanical hard disks appear to still be more reliable than SSDs. The write-cycle limit of SSD has effectively been solved, but they still fail (and tend to fail completely and without warning).

I have never had an SSD completely fail over the last 15 years of using them. I have only lost data here and there on one drive too, and those bad sectors get placed in the "do not use bin" by the drive firmware. Fact is, if you have an electronic failure with either SSD or mechanical drive, the drive is all done. So I don't get why we are not using SSD's.

Mark

| IP: Logged

Marcel Birgelen
Film God

Posts: 3357
From: Maastricht, Limburg, Netherlands
Registered: Feb 2012

posted 07-27-2019 11:50 AM

For many applications I prefer SSDs, simply because of the speed. For a workstation, going back to hard drives feels like going back to the stone age.

But if you look at a NAS for example, the situation is not that clear cut. It really depends on the type of data on there and the access patterns.

The primary reason for not using SSDs in cinema servers would be the cost difference. The gap between "consumer grade" SSDs and hard drives is still steadily closing in regarding to pricing and "consumer grade" SSDs should be sufficient for most DCI applications.

Please notice that even those SSDs that are sold as "enterprise" are often just the "consumer" version and not the datacenter version, which is often more than 4 times as expensive. The difference between both is usually the write speed and the number of supported write cycles.

Regarding failure modes: I've had several SSDs go completely bad, they where in a state where nothing worked. I've also had "half-failures" in a RAID, where one defective SSD would make the RAID array crawl. It was pretty hard to find the SSD causing it, because there were like 12 SSDs in the array and none reported any problems.

With hard drives it's almost never a black and white situation, you usually get some warning signs before a hard-drive fails. Even if the electronics fail on a hard drive, data recovery companies are usually capable of still extracting the information from there. Only if a drive arm buries itself into the platter and turns the surface to dust, it's usually over-and-out with the data on there. If the controller of an SSD blows up, there is often no way of getting your data back. SSDs store their data nowhere near sequentially, this is done to balance usage of an SSD more evenly. When the table where what data is stored gets corrupted, it's bye bye for your data. I've seen the latter even happening after firmware updates, where the format of this index changed and the new firmware corrupted the table... I believe it was OCZ branded drive that this happened to.

| IP: Logged

Steve Guttag
We forgot the crackers Gromit!!!

Posts: 12814
From: Annapolis, MD
Registered: Dec 1999

posted 07-28-2019 05:28 AM

I just installed a new IMS2000 and the drives were all 2TB Micron SSDs, from the factory.

According to the latest approved drive sheet, the only approved 2TB drives for the IMS2000 and IMS3000 are Micron SSDs. (two models of them).

| IP: Logged

All times are Central (GMT -6:00)

This topic comprises 3 pages: 1 2 3

Printer-friendly view of this topic

The Film-Tech Forums are designed for various members related to the cinema industry to express their opinions, viewpoints and testimonials on various products, services and events based upon speculation, personal knowledge and factual information through use, therefore all views represented here allow no liability upon the publishers of this web site and the owners of said views assume no liability for any ill will resulting from these postings. The posts made here are for educational as well as entertainment purposes and as such anyone viewing this portion of the website must accept these views as statements of the author of that opinion and agrees to release the authors from any and all liability.