Tape Input-Output error: Difference between revisions
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=Problem= | =Problem= | ||
{{man|8|amdump}} and {{man|8|amflush}} give "Input/output error" messages, such as. | {{man|8|amdump}} and {{man|8|amflush}}, or any application accessing the tape drive, give "Input/output error" messages, such as. | ||
taper: tape weekly-002 kb 0 fm 0 writing filemark: Input/output error | taper: tape weekly-002 kb 0 fm 0 writing filemark: Input/output error | ||
=Solution= | =Solution= | ||
Most in-kernel tape device drivers do not provide very detailed errors back to an applications. Often EIO ("Input/output error") is the catch-all "something went wrong" indication. This can indicate something benign like end-of-tape, or more serious problems such as a failing tape drive (see [[How To:Diagnose a Failing Tape Drive]]), bad cabling, or even a hapless operator removing a tape from a running drive. | |||
Amanda ''guesses'' how large a dump will be, and uses the "length" parameter as an estimate of tape size. The dump estimate can change on a system in constant use, and tape cartridges can contain a bit more or less tape than advertized (due to stretch, etc.). So sometimes Amanda, despite its best intentions, writes off the end of a tape. When this happens, you will often see a message like "Input/output error," and in this case the error is fairly benign -- Amanda will keep the dump on the holding disk (you '''do''' have a holding disk, right?) and flush it to tape on the next amflush or, if you have "autoflush yes", on the next amdump run. |
Latest revision as of 16:38, 18 August 2008
This article is a part of the Troubleshooting collection.
Problem
amdump(8) and amflush(8), or any application accessing the tape drive, give "Input/output error" messages, such as.
taper: tape weekly-002 kb 0 fm 0 writing filemark: Input/output error
Solution
Most in-kernel tape device drivers do not provide very detailed errors back to an applications. Often EIO ("Input/output error") is the catch-all "something went wrong" indication. This can indicate something benign like end-of-tape, or more serious problems such as a failing tape drive (see How To:Diagnose a Failing Tape Drive), bad cabling, or even a hapless operator removing a tape from a running drive.
Amanda guesses how large a dump will be, and uses the "length" parameter as an estimate of tape size. The dump estimate can change on a system in constant use, and tape cartridges can contain a bit more or less tape than advertized (due to stretch, etc.). So sometimes Amanda, despite its best intentions, writes off the end of a tape. When this happens, you will often see a message like "Input/output error," and in this case the error is fairly benign -- Amanda will keep the dump on the holding disk (you do have a holding disk, right?) and flush it to tape on the next amflush or, if you have "autoflush yes", on the next amdump run.