bj.8.trades

Yeah, that's what I meant. You know, they style the product as the finest virtual drive software available… Uh, right! Thanks! I've seen lots of postings where it's implied these MD5 values don't really matter, and comparing to image files is the only thing that counts, but I find them very useful! (I know there are situations where the values are expected to be different, of course.)

I've recently broached a topic regarding broken reading of multi-session DVDs. The issue I'm about to describe would naturally be expected when the created image file is significantly bigger than what's on the DVD. Reading multi-session CDs works just fine, though. The images can even be mounted by the virtual drive software, MagicDisc, via the .CCD layout file (if you selected the option for creating it along with the image file), with all sessions fully visible to the operating system. Oddly enough, when the same files are mounted by CloneCD (the originator of the .CCD format, as I understand it), the OS only sees the first session. The situation in question is where you read/create such an image file from a multi-session CD, then verify that same CD (without comparing against the image file.) You'll see that the MD5 values don't match... I 20:35:27 ImgBurn Version 2.5.0.0 started! I 20:35:27 Microsoft Windows XP Professional (5.1, Build 2600 : Service Pack 3) I 20:35:27 Total Physical Memory: 2,096,344 KB - Available: 1,629,852 KB W 20:35:27 SPTD can have a detrimental effect on drive performance. I 20:35:27 Initialising SPTI... I 20:35:27 Searching for SCSI / ATAPI devices... I 20:35:28 Found 4 DVD-ROMs, 2 DVD±RWs and 1 DVD±RW/RAM! I 22:29:52 Operation Started! I 22:29:52 Source Device: [2:0:0] HL-DT-ST DVDRAM GSA-H62N CL00 (V:) (ATA) I 22:29:52 Source Media Type: CD-R (Disc ID: 97m31s07f) (Speeds: 4x, 8x, 16x, 24x) I 22:29:52 Source Media Sectors: 28,433 I 22:29:52 Source Media Size: 66,874,416 bytes I 22:29:52 Source Media Volume Identifier: TestCD 01 I 22:29:52 Source Media Volume Set Identifier: 3B5CB38FC4A34C70 I 22:29:52 Source Media Application Identifier: Nero Burning ROM I 22:29:52 Source Media Implementation Identifier: Nero I 22:29:52 Source Media File System(s): ISO9660, Joliet, UDF (1.02) I 22:29:52 Read Speed (Data/Audio): MAX / MAX I 22:29:52 Hardware Read Error Retries: 2 I 22:29:52 Destination File: E:\Temp\TestCD 01.img I 22:29:52 Destination Free Space: 69,993,320,448 Bytes (68,352,852 KB) (66,750 MB) (65 GB) I 22:29:52 Destination File System: NTFS I 22:29:52 File Splitting: Auto I 22:29:55 Reading Session 1 of 4... (1 Track, LBA: 0 - 941) I 22:29:55 Reading Track 1 of 1... (MODE1/2352, LBA: 0 - 941) I 22:29:58 Reading Session 2 of 4... (1 Track, LBA: 12342 - 13096) I 22:29:58 Reading Track 1 of 1... (MODE1/2352, LBA: 12342 - 13096) I 22:30:00 Reading Session 3 of 4... (1 Track, LBA: 19997 - 20776) I 22:30:00 Reading Track 1 of 1... (MODE1/2352, LBA: 19997 - 20776) I 22:30:02 Reading Session 4 of 4... (1 Track, LBA: 27677 - 28432) I 22:30:02 Reading Track 1 of 1... (MODE1/2352, LBA: 27677 - 28432) I 22:30:08 Image MD5: 1a1c3f1c4096b8e79f99733b844af0b4 I 22:30:08 Exporting Graph Data... I 22:30:08 Graph Data File: E:\Temp\TestCD 01 R_HL-DT-ST DVDRAM GSA-H62N.ibg I 22:30:08 Export Successfully Completed! I 22:30:08 Operation Successfully Completed! - Duration: 00:00:12 I 22:30:08 Average Read Rate: 5,442 KB/s (31.6x) - Maximum Read Rate: 12,384 KB/s (71.9x) I 22:39:40 Operation Started! I 22:39:40 Source Device: [2:0:0] HL-DT-ST DVDRAM GSA-H62N CL00 (V:) (ATA) I 22:39:40 Source Media Type: CD-R (Disc ID: 97m31s07f) (Speeds: 4x, 8x, 16x, 24x) I 22:39:40 Source Media Sectors: 28,433 I 22:39:40 Source Media Size: 58,230,784 bytes I 22:39:40 Verify Against Image File: No I 22:39:40 Read Speed (Data/Audio): MAX / MAX I 22:39:42 Verifying Session 1 of 4... (1 Track, LBA: 0 - 941) I 22:39:42 Verifying Track 1 of 1... (MODE1/2048, LBA: 0 - 941) I 22:39:47 Verifying Session 2 of 4... (1 Track, LBA: 12342 - 13096) I 22:39:47 Verifying Track 1 of 1... (MODE1/2048, LBA: 12342 - 13096) I 22:39:50 Verifying Session 3 of 4... (1 Track, LBA: 19997 - 20776) I 22:39:50 Verifying Track 1 of 1... (MODE1/2048, LBA: 19997 - 20776) I 22:39:52 Verifying Session 4 of 4... (1 Track, LBA: 27677 - 28432) I 22:39:52 Verifying Track 1 of 1... (MODE1/2048, LBA: 27677 - 28432) I 22:39:54 Device MD5: 9afe448ffafa5608abc159015d9562d4 I 22:39:58 Operation Successfully Completed! - Duration: 00:00:14 I 22:39:58 Average Verify Rate: 4,738 KB/s (31.6x) - Maximum Verify Rate: 9,786 KB/s (65.2x) However, the same test, run on a single-session CD, results in no such discrepancies. Boo-Hoo!!! (I've run the same test with other multi and single session CDs... same story.)

Let's put it this way: if I copy the "screwed up" image (which is 6,160,973,824 bytes in this case) to another image file, skipping the first session by starting at offset LBA 723408, the resulting copy will be perfect: session 1 followed by session 2, just as if I did a raw sector-by-sector of the disc itself... like IsoBuster does... A .cue file: FILE "D0422 Backup.iso" BINARY REM ORIGINAL MEDIA-TYPE: DVD+R REM SESSION 01 ; Not supported by other applications (*) TRACK 01 MODE1/2048 INDEX 01 00:00:00 REM MSF: 00:00:00 = LBA: 0 REM SESSION 02 ; Not supported by other applications (*) TRACK 02 MODE1/2048 INDEX 01 160:45:33 REM MSF: 160:45:33 = LBA: 723408 REM (*) SESSION directives are unfortunately not properly supported REM 'out there'. IsoBuster however supports them ! Incidentially, this is more-or-less just like what ImgBurn would create for a multi-session CD. Wish there was a virtual-drive package out there that could use it -- nice and simple (for this particular purpose, anyway.) Also incidentially, IsoBuster can create such .cue files from a quick scan of the physical disk, without having to write an image. Wouldn't that be a great feature to have around for other files like .ccd, .mds, etc. Then you could replace a lost control file without having to re-rip the whole disc (well, if it's a "simple" one, anyway.)

Here 'tis: HL-DT-ST DVDRAM GSA-H62N CL00 (ATA) Current Profile: DVD+R Disc Information: Status: Incomplete Erasable: No Sessions: 3 Sectors: 2,284,880 Size: 4,679,434,240 bytes Time: 507:47:05 (MM:SS:FF) File System Information: Sectors: 2,284,880 Size: 4,679,434,240 bytes Time: 507:47:05 (MM:SS:FF) TOC Information: Session 1... (LBA: 0) -> Track 01 (Mode 1, LBA: 0 - 723407) Session 2... (LBA: 2296280) -> Track 02 (Mode 1, LBA: 723408 - 2284879) -> LeadOut (LBA: 2284880) Track Information: Session 1... -> Track 01 (LTSA: 0, TS: 721360, LRA: 0) Session 2... -> Track 02 (LTSA: 723408, TS: 1561472, LRA: 0) Disc Control Blocks Information: SONY DW-D26AJWS6 Physical Format Information (Last Recorded): Disc ID: CMC MAG-E01-00 Book Type: DVD+R Part Version: 1 Disc Size: 120mm Maximum Read Rate: Not Specified Number of Layers: 1 Track Path: Parallel Track Path (PTP) Linear Density: 0.267 um/bit Track Density: 0.74 um/track First Physical Sector of Data Area: 196,608 Last Physical Sector of Data Area: 2,491,711 Last Physical Sector in Layer 0: 0 Hmm... interesting how the "Session N... (LBA: N)" lines don't show a begin-end range, and the 2nd session indicates a LBA* way at the end of the disk. Compare to the info from the small test CD mentioned earlier... HL-DT-ST DVDRAM GSA-H62N CL00 (ATA) Current Profile: CD-R Disc Information: Status: Incomplete Erasable: No Sessions: 3 Sectors: 13,097 Size: 26,822,656 bytes Time: 02:56:47 (MM:SS:FF) File System Information: Sectors: 12,841 Size: 26,298,368 bytes Time: 02:53:16 (MM:SS:FF) TOC Information: Session 1... (LBA: 0 - 941) -> Track 01 (Mode 1, LBA: 0 - 941) -> LeadOut (LBA: 942) Session 2... (LBA: 12342 - 13096) -> Track 02 (Mode 1, LBA: 12342 - 13096) -> LeadOut (LBA: 13097) Track Information: Session 1... -> Track 01 (LTSA: 0, TS: 940, LRA: 0) Session 2... -> Track 02 (LTSA: 12342, TS: 753, LRA: 0) ATIP Information: Disc ID: 97m31s07f Manufacturer: Ritek Co. Start Time of LeadIn: 97m31s07f Last Possible Start Time of LeadOut: 74m45s01f * This poster needs an English/grammar lesson: should it be, "a LBA", or, "an LBA"? The first doesn't sound right, unless you read it as, "a Logical Block Address."

When I read Nero Backup multi-session (2, in this case) DVDs to an image, the resulting file contains the first session, followed by the first session again, then the 2nd session. Here's the appropriate snippet of a log file, in case it's of any use... I 20:04:56 ImgBurn Version 2.5.0.0 started! I 20:04:56 Microsoft Windows XP Professional (5.1, Build 2600 : Service Pack 3) I 20:04:56 Total Physical Memory: 2,096,344 KB - Available: 1,663,984 KB W 20:04:56 SPTD can have a detrimental effect on drive performance. I 20:04:56 Initialising SPTI... I 20:04:56 Searching for SCSI / ATAPI devices... I 20:04:56 Found 4 DVD-ROMs, 2 DVD±RWs and 1 DVD±RW/RAM! I 20:15:18 Operation Started! I 20:15:18 Source Device: [2:0:0] HL-DT-ST DVDRAM GSA-H62N CL00 (V:) (ATA) I 20:15:18 Source Media Type: DVD+R (Book Type: DVD+R) (Disc ID: CMC MAG-E01-00) (Speeds: 4x, 8x) I 20:15:18 Source Media Sectors: 2,284,880 (Track Path: PTP) I 20:15:18 Source Media Size: 4,679,434,240 bytes I 20:15:18 Source Media Volume Identifier: 18 Tryouts 31_3 I 20:15:18 Source Media File System(s): ISO9660, Joliet I 20:15:18 Read Speed (Data/Audio): MAX / 8x I 20:15:18 Hardware Read Error Retries: 2 I 20:15:18 Destination File: G:\Temp\D0422 Backup_3.img I 20:15:18 Destination Free Space: 132,635,914,240 Bytes (129,527,260 KB) (126,491 MB) (123 GB) I 20:15:18 Destination File System: NTFS I 20:15:18 File Splitting: Auto I 20:15:18 Reading Session 1 of 2... (1 Track, LBA: 0 - 723407) I 20:15:18 Reading Track 1 of 1... (MODE1/2048, LBA: 0 - 723407) I 20:17:19 Reading Session 2 of 2... (1 Track, LBA: 0 - 1561471) I 20:17:19 Reading Track 1 of 1... (MODE1/2048, LBA: 723408 - 2284879) I 20:22:50 Image MD5: f75296fa0a4e159568a59302b13df10e I 20:22:50 Exporting Graph Data... I 20:22:50 Graph Data File: G:\Temp\D0422 Backup_3 R_HL-DT-ST DVDRAM GSA-H62N.ibg I 20:22:50 Export Successfully Completed! I 20:22:50 Operation Successfully Completed! - Duration: 00:07:27 I 20:22:50 Average Read Rate: 10,223 KB/s (7.4x) - Maximum Read Rate: 17,959 KB/s (13.0x) There's no indication of anything unusual in the log file, of course. The operation takes some time beyond when the progress-bar hits 100%... getting that extra session copy processed, I guess. ;-) I thought maybe this is behaviour is specific to Nero-created (or just Nero BackItUp in particular, vs. Burning ROM, etc.) discs, or even multi-session on DVD+R media. I ran another test, using Roxio CD-Creator to burn 2 UDF/ISO9660/Joliet data sessions to a DVD-R. Same results. I also burned a multi-session CD -- that one ImgBurn read just fine, no duplication of tracks. It's notable that both Nero and Roxio warn that multi-session on DVD (presumably, since I'm pretty sure you don't get the warning burning multi-session CDs) recordable media may be unreadable to the OS. And while the OS seems to have no problem with the discs themselves, I've only found 2 products so far that can make fully functional images from them: IsoBuster (which reads it's images fine but, when they're mounted by virtual-disk products, only the 1st session "comes through"), and DaemonTools. I prefer making images with ImgBurn, because an MD5 is calculated on the fly, and the graph files are sometimes interesting.

I know for a fact there is (or was, anyway) software that could mount a ZIP archive as a virtual disk, the same way dozens of freely available tools can mount ISO image files as virtual CD/DVDs. I'd be surprised if such a thing didn't exist for RAR archives -- perhaps even multipart ones (similar to how Norton Ghost is able to create multipart hard disk images, and mount them as virtual disks.) It shouldn't take the proverbial Rocket Scientist to conclude how the ability to make a RAR archive appear as a disk, would apply to the original request in this thread. Even if I'm wrong and there's no such thing at present (or impractically expensive), perhaps Frog would better focus his efforts on getting someone to implement it, thus killing many more birds than would be bagged by another feature extension to ImgBurn's already impressive portfolio!