Discussion Forums > Technology
Moving large amounts of data between HDDs... CRC "fail"?
boxer4:
For me, invariably when there's a single byte corruption in a file when transferring large amounts of data from disk to disk (whether HDD to optical, etc.) I've always rootcaused it to bad RAM. Don't know why but it happened... This also could mean bad motherboard that's not compatible with RAM but still it's a memory issue.
I have had bad disk controllers, CPUs, etc. too, but they tend to fail in other ways other than bad CRCs in large files...
I've yet to have a LAN adaptor fail in such way to cause bad data to be copied... we'll see...
zzzYuyu:
It's always a memory problem. I have the very same problem with rtorrent and rutorrents automove feature, it usually reported uncompleted chunks when moving large completed files.
Funny thing is both of my ram sticks are healthy, it's just the ram controller that tends to cause errors when both ram sticks are plugged in.
megido-rev.M:
Data transfer in general always involves loading and copying buffers, which would involve RAM in all cases. Network transfers are more fragile, and the probability of corruption has to do with how well the network channels can keep packets intact-- unlike disks, which have direct memory access (DMA) and such. Even then, it's all on the controllers and buses to keep things intact.
boxer4:
Newer LAN cards are also "DMA" or rather whatever PCI does to write straight to memory.
LAN, because it's implied that theres a significant distance to go, is usually CRC-checked and this is a form of error detection. The likelyhood of corruption over LAN due to the wire is very low due to the automatic retransmits if the wire data is bad. However the chance of a bad DMA copy from the LAN chip to main memory is possible... but once again this is a RAM issue not a network card issue.
SATA and UDMA are also CRC checked. so I guess for most things, RAM/chipset is the weakest part of the link (CPU caches are ECC checked!)
Time to buy machines with ECC RAM? People keep on saying this but costs keep on entering the equation, when you buy good RAM it makes ECC checks virtually unnecessary...
Definitely get a RAM check program, memtest86+ spotted errors on many of the machines I had corruption issues on. But not all - I still have one machine that shows up clean on memtest86+ but still crashes randomly... CPU issue possibly.
megido-rev.M:
I use USB WLAN connections, so take that! :laugh:
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version