creating ddp from 2xDLT for DVD-9 using windows copy command

kvshulman · Joined: 24 Aug 2006 Posts: 9 Location: melbourne

hi there
i have two DLT tapes from which i have to create duplicate tapes. the tapes are for a DVD-9 title. by using GPME's "restore files from tape" function i can extract the image from each tape. of course what i need in order to create the new tapes is one image not two, so apparently i have to "combine" the two files using the copy command in DOS (see "How to restore a CD-ROM or DVD DDP image to disk" in the GEAR How To guides) This all makes sense, but is there not a filesize limit when copying files using DOS? When i tried to combine the layer 0 image with the layer 1 image using the DOS command "copy layer1.dat+layer2.dat dvd9.dat", the resultant file dvd9.dat was only 554kb. i tested the DOS syntax by combining two txt files, one with "abc" in the text and one with "def" in the text. sure enough, the resultant file contained the text "abcdef", so i'm pretty sure the command is correct. has anyone successfully combined two dat files from tape using the copy command in DOS? my layer 0 file was 3.5GB, layer 1 was 1.6GB. I have half a GB of RAM available and i can make straight copies of either of these files using DOS quite succesfully. whats going on?
thanks for taking the time to read this.
ken

neilwilkes · Posted: Fri Aug 25, 2006 3:11 pm Post subject:

Do you absolutely have to get these back to DLT?
Will your replication facility accept 2 DVD-R discs with the relevant DDP images written onto them instead?

kvshulman · Joined: 24 Aug 2006 Posts: 9 Location: melbourne

hi neil
thanks for the reply.
yes the facility will accept 2xdvdr but ive never done it as tape is so much more reliable. so would i drop the image for each into ISO/UDF DVD-ROM sessions? what about the control.dat and ddpid files that also come off the tape? any idea why my DOS combine files function didnt work?
cheers mate
ken

kvshulman · Joined: 24 Aug 2006 Posts: 9 Location: melbourne

OK ive sorted this out. i'm putting the solution to my own problem here so that others dealing with DLT can track it down if need be.
the gear "how to" guide www.gearsoftware.com/support/documentation/restoreddpimage.cfm
seems to have omitted an important piece of info regarding the copy command in DOS:
to "merge" two .dat files you cannot use the command
"copy file1.dat+file2.dat file3.dat"
because the files are not just .txt files - you have to use a "switch" in the syntax so that DOS understands that youre using binary files (eg .dat).
therefore the correct command is
"copy/b file1.dat+file2.dat file3.dat"
/b is the required switch and seems to make all the difference.
ken shulman

Michael Szabo · Posted: Tue Aug 29, 2006 1:29 pm Post subject:

Michael Szabo · Posted: Wed Aug 30, 2006 2:52 pm Post subject:

The How-To guide for restoring images from DLT tapes has been revised to properly instruct the use of the copy command to include the '/b' switch

neilwilkes · Posted: Wed Aug 30, 2006 3:19 pm Post subject: Re: dvdr instead of dlt?

kvshulman · Joined: 24 Aug 2006 Posts: 9 Location: melbourne

michael/neil
thanks guys. michael do you think a future version of GEAR could make a single function of ripping and combining the dat files? thatd be handy. anyway for now i can do everything i want to do so i'm happy. neil, i also tried submitting the DDP on DVD-R as you suggested. it didnt actually work but only because i called layer 0 "main1" and layer 1 "main2". i felt i had to differentiate between them on my hard drive but i presume they both have to be called "main.dat" or at least the same thing. i also noticed that it is only layer 0 that has the control.dat file.
anyway cheers for your input,
ken