+--On 5 septembre 2015 20:37:41 -0600 Warren Block <wbl...@wonkity.com> wrote: | On Sat, 5 Sep 2015, Allan Jude wrote: | |> On 2015-09-05 20:11, Ali Ghahraei wrote: |>> Good afternoon. |>> |>> I just wanted to inform you about an error in the handbook (or at least |>> I think it is one). In "Pre-Installation Tasks" there is a command for |>> burning disk images, but it currently is: |>> |>> # dd if=*FreeBSD-10.0-RELEASE-amd64-memstick.img* of=/dev/*da0* bs=1m |>> # conv=sync |>> |>> And I think it should be: |>> |>> # dd if=*FreeBSD-10.0-RELEASE-amd64-memstick.img* of=/dev/*da0* bs=1M |>> # conv=sync |>> |>> With a capital m in bs. This is because I tried to use the command and |>> it returned dd: invalid number: '1m'. |>> |>> I apologize if my English is not too good, but I'm not from an |>> English-speaking country. I send you this message because I wanted to |>> help you. I hope it is useful :) |> |> Only the Linux utilities are sensitive to the case of the unit, but yes, |> we should change it in the documentation. | | The device name will not be correct on Linux, either. That is a | FreeBSD-specific command. We could add a Linux variation, but it ought | to explain how to determine the correct device to write. | | Incidentally, we should test using conv=sync,noerror,sparse. The last | one in particular could make writing memory sticks faster.
I'm really not sure the sparse would do any good, the memsticks img are filesystems created with makefs, which packs files in a filesystem image without leaving any holes. (I mean, of course there will be sectors that are not full, but you always have to write to a nand cell in one go, and cells are much bigger than sectors.) What helps is the bs=1m, because it doesn't go and write 512 bytes at a time (when the cell size is, say, 512kB, it means the same cell is overwritten 1024 times before it's full, which *is* the part that makes it slow.) -- Mathieu Arnold
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