Does ECC RAM Protect an External HDD?

Luddite

Senior member
Nov 24, 2003
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If I attach an external drive (not a NAS, just a drive) to a workstation with ECC memory, does the ECC also protect the data on the disk in an external enclosure?

Is an external drive considered part of the same system used by the RAM? Or does the RAM only apply to what is inside the computer itself?
 

dlerious

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Mar 4, 2004
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If I attach an external drive (not a NAS, just a drive) to a workstation with ECC memory, does the ECC also protect the data on the disk in an external enclosure?

Is an external drive considered part of the same system used by the RAM? Or does the RAM only apply to what is inside the computer itself?
Doesn't matter if it's internal or external, The error correction is only for the RAM.
 
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mikeymikec

Lifer
May 19, 2011
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@Luddite , can you elaborate on your question a bit? I have the feeling that your misunderstanding has a root point which wasn't purely your original question.
 

Luddite

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Nov 24, 2003
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My understanding is that ECC memory helps protect against bit flipping of data when working with files. For the files that are stored on the inside of a computer when the OS and RAM and storage are all on the same system (so to speak), this seems pretty straightforward to understand I guess my question is, when working with data on an external drive (which would still require RAM memory to work with, no?) does the error correction still operate when working with data on external disks?

This question came up when I was looking into NAS storage devices, and whether or not it's worth getting one with ECC memory (which are usually much more expensive). So I thought, what if I just have an external HDD? I realize a NAS is kind of its own computer. This got me thinking about why a NAS might have ECC memory in the first place if it's already connected to a computer with ECC RAM, and whether working with data in an external HDD is still protected by the ECC memory from an attached computer?

Hope this is clearer.
 

aigomorla

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ECC works only for ram which dlerious states is correct.

Will it work for a external hdd?
Only when your copying or moving data to and from that drive connected directly to the PC with ECC.

Data gets pooled into ram, and then copied onto your drive, so when its pooled and stored in ram, it will make sure the data is error free.

On NAS devices your going to hear a lot of yay, and nae sayers.
On FreeNAS for example, or any FreeBSD based NAS, they say ECC is an absolute must, because of how DB works.
However, there are many that say they have not had 1 problem without ECC, but its your data, how much protection you want on it is totally up to you. You don't need full comprehensive coverage on your auto insurance (example).

Also most NAS's are a computer itself.
Synology, Qnap's and most reputable NAS's are powered by some form of x86/ARM processor and has a network interface card.
They run a small file off internal eMMC flash, or a dedicated sdd.

They do not directly connect to a PC, outside probably initial data migration, since usb3.0 is faster then a straight 1gbe network connection. That is not a definition of NAS... (Network Attached Storage)


Anyhow so to answer your question, if the PC has ECC, and your doing the data migration from that PC with ECC, then yes, your data is being copied with ECC if its directly connected to that PC.

If its a PC with ECC copying data to a NAS without ECC, then no.
The NAS without ECC can theoretically write a error on itself, even tho the PC sending data has ECC.

Your basically looking at the weakest link, there being the NAS without ECC.
 
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VirtualLarry

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You need ECC over the *Complete data path* for it to be any real good. Since my understanding of USB Mass Storage Controller protocol, is only checksums, and even so, USB(3.0?) allows so many UBEs per so much data, so no, without replacing the USB3.0 and Mass Storage Device protocols, ECC on the RAM won't protect them.
 
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