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What are the principal features of an industrial hard drive used in PCs in automation?

What are the most important vendors of industrial hard drives for automation?

On January 5, 2004, jrpabon wrote:
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> What are the principal features of an industrial hard drive used in PCs in
> automation? <

As far as I know, there is no such thing as an "industrial hard drive" per say. There are however a number of things you can do to make a PC more reliable, including not using a hard drive at all. There are options such as thin clients, RAID, removable drives, and various types of solid state drives.

> What are the most important vendors of industrial hard drives for
> automation?
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I have some recent experience in trying to make PCs more reliable in production use. There isn't a single "best" answer which fits all situations. You need to define what your requirements are.

What you first need to determine is how much storage do you need (how big of a drive)? This includes space for the operating system, the application software, and any data files (including data logging). The application software and operating system used will have a significant influence on this.

You also need to determine how frequently and how much the system will write to disk. This has an influence on the types of storage that can be used.

If you can answer the above questions, and also give us a general idea of your application and objectives, then I can make some suggestions.

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Michael Griffin
London, Ont. Canada
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There is also a fairly long and useful thread on this in the archives. If you can't go with a solid state drive because you're using some enormously bloated software, there are two things you can do to help a hdd in industrial settings. Cool it, and isolate it from shock and vibration. Neither is very difficult anymore with today's tiny drives. Don't pack it or stack it and rig rubber mounts for a 3.5" drive in a 5.25" bay and you'll be doing about as well as any "industrial" device. Notebooks are difficult to deal with, but are normally fairly well done out of the box. I've replaced several hdd that got so hot you could smell them when you opened the case. I use a booster fan, Not your rinkydink "PC case fans" but a real 4" boxer or muffin type fan with a filter to pressurize the case. This can lower interior temps
dramatically and pressurizing the case keeps the dirt out if you use an effective filter. Then you're ok even if your pathetic power supply fan dies. If you have an A/D card in the system, it's easy to monitor and alarm on internal temp. If you don't, you can monitor and alarm on
the CPU temp sensor built into recent MBs. The only problem I've had is to get someone to clean or change the filter. If you make the alarm annoying enough and non-cancellable, they'll keep it clean, or call you so you can tell them to read and do what the alarm says.

Regards

cww

The hard drive is 4-10 GB used in a PC running a SCADA application over NT.

Well, then I wouldn't worry so much about the hardware reliability. The measures indicated will help and you can clean the filter every blue screen. :^)

Regards

cww

This will be difficult. With this configuration a solid state drive (probably the best and easiest solution) is not practical with today's technology. You have essentially two options using conventional hard drives; a RAID set up, and a spare drive on hand.

With a RAID set up, you need a mirrored drive configuration. This uses two drives operating in a redundant configuration (they are duplicates operating in parallel). If one drive fails, the other drive can take over, allowing the system to continue to operate until you have a chance to replace the failed drive.

Be sure the complete drive is mirrored, including the operating system. Use a hardware RAID NOT a software RAID (software RAIDs are very troublesome in Windows). A hardware RAID can be implemented using either a special RAID drive controller card, or some newer motherboards offer this feature built in. The RAID system will include special software to automatically "rebuild" the drive set if you replace one drive.

Mount both drives in removable drawers (Startech has a very nice model) to allow you to replace a failed drive without taking the computer apart. Having to dissassemble the computer in this situation would more or less render the whole exericise rather pointless. You may have to replace the computer with a new one to make these changes (RAID controller + dual removable drives) possible.

I suggest you get someone with an IT background to help you implement a RAID system if you decide to use this method. The general concept is "simple", but the actual hands-on implementation of it can be difficult and time consuming. Once it is installed, be sure to test it to see if it really works.

You will require some operating procedures to ensure that the proper corrective action gets initiated if a drive fails. This is one of the seldom considered difficulties with the RAID solution. Since the people using these computers are not computer maintenance people, their typical reaction to a RAID drive failure will be to ingore it until the second drive fails. This again would render a RAID pointless. Keep in mind that since you are doubling the number of drives in use, the number of individual drive failures will *increase* from what you have today.

You may be able to get monitoring software which will send e-mail to someone if a drive failure occurs. Talk to an IT person about this. This sort of software is used for servers. However one of the problems with Windows is that it comes in separate server and client versions. I don't know if a practical form of this is available for a client station.

As an alternative to a RAID system, you may wish to simply keep a spare drive on hand ready to install, with all software already loaded. You would mount the drive in the same sort of drawer as suggested above for the RAID solution, but in this case you would have only one drive. If the drive fails, unplug the bad one, plug in the spare, and reboot. No computer dissassembly is required to recover.

The spare drive on hand solution is very simple and inexpensive. You do have a few minutes of down time while changing a drive, but as someone else pointed out, if you really needed high availability you wouldn't be using Windows anyway.

The one disadvantage to this system is that you must be dilligent in updating the spare drive when you make software changes. However, it does have an advantage over RAID in that it address the problem of software corruption as a cause of failure. In RAID system if the failure is a software as opposed to a hardware problem, the failure will be duplicated in *both* drives, and you have a complete system failure. With the spare drive method, you simply install the spare and you will have recovered from a software failure the same as you would from a hardware failure.

However, Windows again introduces a problem into this scenario. If you are using Windows XP with product activation, you need a separate spare for each computer, and it must be created on that specific computer or else Windows will decide you are a pirate and refuse to run. You stated you are using Windows NT (I assume this is NT4), which does not have this problem. However, you will need to have a solution to this if you use Windows XP (or its successors) in future.

I hope the above has been helpful. Let me know if anything was unclear or if you have any more questions.

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Michael Griffin
London, Ont. Canada
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Thank you Michael, I forgot to add that he should Ghost a copy with any major change in case the filesystem gets scribbled on. Recovery is possible, but changing drives and patching things up is almost always more possible and economical.

Regards

cww

One method is to use cheap flash cards such as compactflash. These can be used with an ATA/IDE -> CompactFlash adapter giving you a solid-state hard disk. The flash may not last as long if the card is being written to continuously for long periods of time but for most situations they are fine. they are also very low power. keep in mind that they are not as fast as most hard disks though. hope this helps. cheers.