I'm running geth with

geth --rpc --rpccorsdomain "localhost"

and ethminer 1.1.4 in a separate terminal, and I've noticed that in the geth console I'm getting a lot of messages that simply just say "short write". E.g.:

I0225 13:05:53.940248 rpc/server.go:347] short write

Couldn't find any documentation on this - anyone know if this is something to worry about?

  • Out of curiousity I downloaded all of the geth source code and couldn't find anything in there, so I'm not sure where it's coming from.
    – womp
    Commented Feb 26, 2016 at 23:42
  • Check the code on server.go:347. It's an error message of codec.Write(), but I can't tell you what it means.
    – q9f
    Commented Feb 27, 2016 at 16:00
  • @5chdn thanks.... the best I've been able to tell is that it's a filesystem problem, perhaps disk space issues. I'm running off a USB stick that only has about 200MB of space left on the system partition, and about 2GB of swap space. It seems to be mining just fine despite the volume of "short writes"... next time I set up a rig I'll increase the system allocations and see if that alleviates it.
    – womp
    Commented Feb 29, 2016 at 17:42
  • So I reformatted my drive and reinstalled everything, this time leaving 7200MB for the Ubuntu system partition instead of 5000. I also upgraded the rig fro 6GB of RAM to 8GB. I am no longer experiencing the "short write" messages.
    – womp
    Commented Mar 2, 2016 at 19:49
  • you can always create answers to your own questions.
    – q9f
    Commented Mar 3, 2016 at 8:41

1 Answer 1


It's a golang input/output error. go/pkg/io

var ErrShortWrite = errors.New("short write")

ErrShortWrite means that a write accepted fewer bytes than requested but failed to return an explicit error. It could be related to your USB device. But to be 100% certain you should report that issue upstream.

  • Awesome, thank you. I'm pretty new to both Go and ethereum and still a bit confused on most things - where would be the proper place to report this?
    – womp
    Commented Feb 29, 2016 at 18:13
  • github.com/ethereum/go-ethereum/issues
    – q9f
    Commented Feb 29, 2016 at 19:10

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