[arch-general] Super weird dd problem.

[Pedro Emílio Machado de Brito]

2013/6/9 Alfredo Palhares <masterkorp at masterkorp.net>:
> Hello,
>
> So I was creating a archlinux usb bootable drive:
>
> [root at masterkorp-laptop Downloads]# dd bs=4M if=archlinux-2013.06.01-dual.iso of=/dev/sdb
> 130+1 records in
> 130+1 records out
> 548405248 bytes (548 MB) copied, 0.964976 s, 568 MB/s
>
> I was like WOW, this was too fast! But nothing ever gets written to
> the pen drive.
> To add to the weird factor, a dd to dev/sdb1 (partition) works as it
> should, slowly. But then ofcourse the iso gets unbootable.
>
> The md5sum on the iso is correct.
> I tried with diferent pen drives.
>
> Please, any suggestions is welcome.
>

I've been having this sort of problems with removable storage lately
(copying multiple GBs of songs in a few seconds, except not really).
The workaround I found out is to run the sync command after copying.
That could take some time as all your data is being actually written
to disk.

I believe this is related to the write cache, please let me know if
you find a better solution to this.

--
Pedro Emílio Machado de Brito

Engenharia de Computação 2012 - Unicamp
Coordenador Tecnológico - Centro Acadêmico da Computação (CACo)
(34) 9673-0963 - Facebook/Skype: pedroembrito - Github: pemb
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