ECC RAM data correction question

[pespn2000]

If I download a large file on a PC without ECC RAM, and in the process corrupted data is written to that PC's drive, when I later transfer that file to a ZFS system with ECC RAM, will the data be corrected?

 

[Dreamerbydesign]

If I download a large file on a PC without ECC RAM, and in the process corrupted data is written to that PC's drive, when I later transfer that file to a ZFS system with ECC RAM, will the data be corrected?

No.

 

[danswartz]

If I download a large file on a PC without ECC RAM, and in the process corrupted data is written to that PC's drive, when I later transfer that file to a ZFS system with ECC RAM, will the data be corrected?

All zfs can do is write what is believed to be valid data with checksum. If bad ram flipped bits, you will have bad data with a valid checksum on the disk

 

[patrickdk]

I had a nic that would randomly change a bit, 1 in around 20gigs of data.

I transfered this data from a hardrive, in 20gig files, over nfs to zfs. As the source was good, it got corrupted somewhere for nfs, as both machines had ecc.

Probably would have solved the issue, if I didn't use tcp checksum offloading.

 

[pespn2000]

Thanks for the replies. I guess bad data is bad data full stop.

 

[brutalizer]

If I download a large file on a PC without ECC RAM, and in the process corrupted data is written to that PC's drive, when I later transfer that file to a ZFS system with ECC RAM, will the data be corrected?

ZFS has no way of knowing how the correct file should look like. ZFS only guarantees that what data it gets, will be stored unaltered. ZFS guarantees the integrity of the data. ZFS is like a safe, whatever you put inside the safe, will be intact. If you put crap in the safe, it will be crap - ZFS can not magically transform it to be better, like gold.