On 12/06/2016 09:40 AM, jd1008 wrote: > > > On 12/06/2016 10:33 AM, Rick Stevens wrote: >> On 12/06/2016 08:56 AM, jd1008 wrote: >>> >>> On 12/05/2016 01:58 PM, Samuel Sieb wrote: >>>> On 12/05/2016 11:45 AM, jd1008 wrote: >>>>> dd does not HAVE to know ANYTHING about the layout. >>>>> The layout is the format of the iso file which was created by the >>>>> fedora >>>>> project for f24 desktop release. >>>>> I am amazed at the lack of technical knowledge on the part of every >>>>> respondent to this problem. >>>> Who said anything about layout? The problem is that the drive needs >>>> to be configured to the right mode and settings and there are extra >>>> operations that need to be run before and after the data is written. >>>> You complain about the "lack of technical knowledge", but do you have >>>> any idea how cdrom drives work and the communication required with >>>> them? Try looking at the source code to growisofs or wodim. A brief >>>> look at the kernel source code suggests that it doesn't support >>>> opening the device for writing unless there's a rewritable medium in >>>> the drive, but I didn't look too closely. I've wasted enough time >>>> already on this topic... >>> You must not have read the whole thread. >>> And you are wrong about configuring the drive. >>> the drive is rather new, and the media is BRAND NEW and undamaged. >>> Thus the drive is detected and recognized at boot time. >>> There is no other "mode" in question, as long as the drive has not been >>> written to and already "sealed", meaning no new session can be created >>> on it. >>> You wre WRONG about "rewritable" too. It has to be only WRITABLE. >> I don't believe we ever said anything about the media itself. The DRIVE >> (and the driver code that manages it) has to be set to write mode by >> sending specific ioctl()s to it. In the past, older versions of the >> driver MAY enable write mode by default, but that is absolutely >> incorrect and has been fixed in later versions (what's the purpose of >> read-only media if you can write to it on a whim or by mistake?) > That cannot happen on media that are finalized. > As far as whim or mistake - that would be no different than > wiping out your home dir by whim or mistake. However one knows that one's home dir is on read/write media. The assumption is that CD and DVD is read-only and impervious (perhaps naively) to write operations. With older drivers, this may not have been the case. Yes, finalized media should be unwritable, but I thought we were talking about putting virgin (or unfinalized) media in a CDR/DVDR drive and being able to write to it via dd or some other method without preliminaries. I'm saying the newer versions of the drivers (if done properly) will not permit that to happen. You must put the driver and the hardware it controls into "writeable" mode first. Someone said dd was "broken" because it couldn't write a CDR and they didn't want to bother using (what I consider) the correct command to perform the operation. To clarify my position, dd is NOT broken. Technically it NEVER should have been able to write CDR (even with virgin or unfinalized media), but the responsibility for blocking that is on the drivers for CDR and DVDR devices, NOT dd (or cp or mv or any other "move data from A to B" command). Those drivers are now behaving properly and blocking write operations unless put into write mode first. Tools like growisofs are specifically designed to do these operations by putting the driver into write mode, doing the write operation and returning the driver to read-only mode in one go. My apologies if I wasn't being clear about this. ---------------------------------------------------------------------- - Rick Stevens, Systems Engineer, AllDigital ricks@xxxxxxxxxxxxxx - - AIM/Skype: therps2 ICQ: 226437340 Yahoo: origrps2 - - - - The problem with being poor is that it takes up all of your time - ---------------------------------------------------------------------- _______________________________________________ users mailing list -- users@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to users-leave@xxxxxxxxxxxxxxxxxxxxxxx
