View Full Version : failed to convert to read-only

09-14-2009, 09:46 PM

For a long time had been using SuperDuper (v 2.5) to back up my MacBook Pro (OS X 10.4.11) to an external drive (readyNAS NV) --- things had been working fine. I then updated to OS X 10.5.8 and seem to recall (but not 100% sure about this) that things still worked fine. I don't use Time Machine at present ... rather a single Smart Update scheme serves my current purposes.

Its been way too long since the last backup, but I sadly can no longer get things to work. Did a smart update and ran into disk permission problems.

Fooled around w/various things, but ultimately ditched the old sparse backup and started from scratch (also upgraded from SuperDuper 2.5 to 2.6). Had manually mounted the NAS (via AFP) and then used Disk Utility to create a fresh sparse image as described here:


Then told Superduper to do a fresh copy, which seemed to go fine, except upon "After Successful Copy" I get the error:

"Failed to convert [disk image on nas] to read-only"

What am I doing wrong?

Here's some of the log:

PHASE: 3. After Successful Copy
| 02:21:47 AM | Info | ...ACTION: Converting zen to read-only
| 02:21:47 AM | Info | ......COMMAND => Converting '/Volumes/afp_bthom_bootables/zen.dmg' to UDRO format
| 02:22:25 AM | Info | Preparing imaging engine…
| 02:22:30 AM | Info | Reading Protective Master Boot Record (MBR : 0)…
| 02:22:30 AM | Info | (CRC32 $AB5F5DDF: Protective Master Boot Record (MBR : 0))
| 02:22:30 AM | Info | Reading GPT Header (Primary GPT Header : 1)…
| 02:22:31 AM | Info | (CRC32 $AC355B48: GPT Header (Primary GPT Header : 1))
| 02:22:31 AM | Info | Reading GPT Partition Data (Primary GPT Table : 2)…
| 02:22:31 AM | Info | (CRC32 $483561E2: GPT Partition Data (Primary GPT Table : 2))
| 02:22:31 AM | Info | Reading (Apple_Free : 3)…
| 02:22:32 AM | Info | (CRC32 $00000000: (Apple_Free : 3))
| 02:22:32 AM | Info | Reading EFI System Partition (C12A7328-F81F-11D2-BA4B-00A0C93EC93B : 4)…
| 02:23:58 AM | Info | (CRC32 $125D7C7B: EFI System Partition (C12A7328-F81F-11D2-BA4B-00A0C93EC93B : 4))
| 02:23:58 AM | Info | Reading disk image (Apple_HFS : 5)…
| 07:02:19 PM | Error | hdiutil: convert failed - Input/output error

Thanks very much for any help you can give!


p.s. I'm also confused about the file names stored on the Nas drive. I find a zen.dmg (created around 7pm, and perhaps produced from some prior messing around?), a zen.dmg.sparseimage (created around 2:30 am, 115 GB, about the size of the used portion of the MacBook drive) and a zen.sparseimge (created around 3:30 am, 100 MB). Are these files all related to one another? Are some the result of SuperDuper not having been able to completely finish its business?

09-14-2009, 09:56 PM
Try creating a read/write "sparse" image rather than a read-only image.

09-15-2009, 02:48 AM
So in the interim can I delete:


I was hoping if, in the interim, I just kept zen.dmg.sparseimage (as a worst-case scenario b/u until I get SuperDuper running to completion) that would be sufficient should something catastrophic happen. (I'm still confused about what these other files might be for.)

09-15-2009, 08:51 AM
Since I don't have the full log, I'm really not sure why you have all three of those files. We actually try to clean up after this stuff when the copy fails. Perhaps you created a sparse image and then also checked the "image" option in the advanced tab of Options at some point?

09-15-2009, 12:29 PM
It is entirely plausible this is what ended up happening (before I contacted this list I had done some messing around).

Another question for you: what kind of partition should I choose? I'm storing this on a NAS (N/W server) but would like the option of copying it over to a bootable-Mac external firewire drive and would be delighted if I could just boot a potentially-sometime broken MacbookPro from there.

One option is "single partition - master boot record part. map"
Another is "single part - GUID part. map"

and there are many others. Of course I'd only want to boot this via firewire from an Intel Mac.

Thanks SO MUCH for your excellent responses.