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linstadt
09-26-2004, 05:26 PM
Has anyone had problems with corrupted files on SD and CompactFlash cards by SanDisk? We took our Canon A-80 digital with SanDisk 512 mb compact flash to Grand Cayman, took 135 pics, watched them on a roadstar there and when we got home, we had a corrupted disk. Sent it to Image Recovery Pro, and they retrieved and said it was corrupted FAT.

We just got the new Kodak Easy Share DX7590 and we got a San Disk 128 mb SD with the camera, took 60 pics with it and loaded it on dock and had corrupted files. Recovery program could read 59 and 56 photos. We reformatted the disk.

We have never had this problem with any other CF or SD cards. Has anyone else experienced this? If so, what did you do? Thanks.
L

Rhys
09-26-2004, 05:59 PM
Has anyone had problems with corrupted files on SD and CompactFlash cards by SanDisk? We took our Canon A-80 digital with SanDisk 512 mb compact flash to Grand Cayman, took 135 pics, watched them on a roadstar there and when we got home, we had a corrupted disk. Sent it to Image Recovery Pro, and they retrieved and said it was corrupted FAT.

We just got the new Kodak Easy Share DX7590 and we got a San Disk 128 mb SD with the camera, took 60 pics with it and loaded it on dock and had corrupted files. Recovery program could read 59 and 56 photos. We reformatted the disk.

We have never had this problem with any other CF or SD cards. Has anyone else experienced this? If so, what did you do? Thanks.
L

Corrupted FATs arenot uncommon. I, for one, am somewhat surprised that camera manufacturer use such a weak file management system. How many times do you find "lost file fragments" under DOS, Windows 3.1/95/98/ME/SE? Plenty - it's a ghastly system! Under NT, 2000 and XP, the NTFS file system is used.

linstadt
09-26-2004, 07:34 PM
Corrupted FATs arenot uncommon. I, for one, am somewhat surprised that camera manufacturer use such a weak file management system. How many times do you find "lost file fragments" under DOS, Windows 3.1/95/98/ME/SE? Plenty - it's a ghastly system! Under NT, 2000 and XP, the NTFS file system is used.

What can I do to prevent this from happening? It happened with 2 different cameras yet the same San Disk product. Will formatting the disk when used the first time help this?

Will I have to keep sending it to pro imagary recovery to recover pictures?
Linda

judge9847
09-27-2004, 09:06 AM
Corrupted FATs arenot uncommon. I, for one, am somewhat surprised that camera manufacturer use such a weak file management system. How many times do you find "lost file fragments" under DOS, Windows 3.1/95/98/ME/SE? Plenty - it's a ghastly system! Under NT, 2000 and XP, the NTFS file system is used.
It would be helpful if Rhys could explain, in layman's terms, what the FAT system was and what the difference is between it and the NT File System. That way his comments might be better understood by the less technically minded. Over to you Rhys.


What can I do to prevent this from happening? It happened with 2 different cameras yet the same San Disk product. Will formatting the disk when used the first time help this?

Will I have to keep sending it to pro imagary recovery to recover pictures?
Linda

I've recently experienced a SanDisk problem with one of their UltraII 256MB cards. Cutting an extraordinarily long story short, the problem revolved around a file of over 111MB was created for just one image. I have no idea why that happened or whether it was the camera or the card that did the dirty deed. But as I've never used the card before and the camera has never mis-behaved in that way before, I'm left thinking that it is - probably - a fault of the card.

A Google search does reveal quite a large number of complaints/obervations about the SanDisk SD cards. Maybe there's an inherent problem with them.

However, there are a number of utilities that you can buy that will recover images or SanDisk themselves supply, on a mini-CD that was enclosed with my card, their own utility to recover "lost" images.

My own experience was that it didn't work but I'm sure that was an issue connected with my PC setup and not the utility itself.

I ended up buying a utility that did the job perfectly. You can either do that - and I would recommend the one I used of course! - or if you chose, send your cards to a recovery company to do. That's likely to be more expensive but if you're not that technically minded, it may be your solution. But don't be put off from attempting it yourself: it's a very simple process and I'm sure that you'd cope.

However, it hasn't happened again ... touch wood and I'm leaving the card in the camera all the time. It may happen again but I do have a solution.

All that apart, I'm happy with the performance of the card which writes very quickly and leaves my camera ready for action that much sooner. However, I won't be buying another UltraII card of any size!

linstadt
09-27-2004, 05:05 PM
Thanks Bob for you easy to understand response. When you mentioned the large files, that happened with the SanDisk SD card, some files where huge!!! Let me know what recovery software you purchased. I can only learn. Obviously with my grandma's 99th birthday party, I am not using the san disk product. Going with one we've used in the past.

Waiting for Rhys to respond in layman's terms :) Thanks again.
Linda

judge9847
09-27-2004, 05:47 PM
Thanks Bob for you easy to understand response. When you mentioned the large files, that happened with the SanDisk SD card, some files where huge!!! Let me know what recovery software you purchased. I can only learn. Obviously with my grandma's 99th birthday party, I am not using the san disk product. Going with one we've used in the past.

Waiting for Rhys to respond in layman's terms :) Thanks again.
Linda
I don't blame you for one moment using something that you trust for such an important event - a 99th birthday really is a once-in-a-lifetime thing and not to be messed around with :)

I found that Digital PhotoRescue Pro was the answer. It allows you to start the recovery at any place you tell it to on the card. If you can imagine the card made up of "sectors", hundreds of thousands of them, any one of your photographs will occupy a number of them. My own problem seemed to be with the first image and I was able to tell the software to start the recovery by beginning at sector 1025. Without boring you with the details - and please forgive me if you know all this already - 1024 is a magic number in the world of computers - it's 2x2x2x2x2x2x2x2x2x2 - so I guessed that 1025 would be the place to sort of "bypass" the first image. I've no idea if that was really the right way to look at it but by starting there, I managed to recover 245 photographs. I didn't find another piece of software that allowed me to start at a given point on the card though of course there may be others. But that was the essential key for me.

Once I'd got the photos on to the hard drive, I backed them up to a CD and then reformated the card. Twice, just to make sure!

You can trial the software but any files it recovers in that mode are heavily stamped to prevent you sensibly using them. It's available from ObjectRescue.com (http://www.objectrescue.com/products/photorescuepro/)

I trialled it, found it worked and then bought a release key which stopped each image being stamped with the "trial" message. It cost $25 I think it was and it saved my hide!! I reckon it was worth every penny. And if it should happen again - oh no!! :eek: - I have it immediately to hand.

One more thing to think about. If you've got Norton Utilities there is a Rescue function there and that may work. Again, it's not difficult to use and why spend money you don't have to. I couldn't use it because every time I tried, the PC crashed. I now believe that was because of the problems with that first image.

And I almost forgot. Please wish Grandma a very happy 99th Birthday. And tell her we will insist on seeing some photos of her on the big day and even more next year on her 100th :) Did you know that here in the UK, everyone who reaches that age gets a personal message of congratulations from the Queen? I've always felt that is a great gesture to make.

Rhys
09-28-2004, 08:09 AM
It would be helpful if Rhys could explain, in layman's terms, what the FAT system was and what the difference is between it and the NT File System. That way his comments might be better understood by the less technically minded. Over to you Rhys.


Description of FAT system (http://www.hitachigst.com/tech/techlib.nsf/techdocs/BB4945CEAAE4DAD986256D890016E8F4/$file/Introduction_to_FAT.pdf)


Description of the NTFS filing system (http://www.digit-life.com/articles/ntfs/)

further reading on NTFS
http://www.webopedia.com/TERM/N/NTFS.html
http://www.winntmag.com/Articles/Index.cfm?IssueID=27&ArticleID=3455

Basically, NTFS is more secure because the index is held in two locations and because files are generally less fragmented, thus allowing easier recovery.

In my experience of FAT 16/32 and NTFS 4/5, I never have had "lost clusters" under NTFS wheras almost every time I run a windows 98 system, I find lost clusters. Lost clusters often means lost data - this is bad. NTFS doesn't lose data in the same way - this is good.

judge9847
09-28-2004, 10:20 AM
Description of FAT system (http://www.hitachigst.com/tech/techlib.nsf/techdocs/BB4945CEAAE4DAD986256D890016E8F4/$file/Introduction_to_FAT.pdf)


Description of the NTFS filing system (http://www.digit-life.com/articles/ntfs/)

further reading on NTFS
http://www.webopedia.com/TERM/N/NTFS.html
http://www.winntmag.com/Articles/Index.cfm?IssueID=27&ArticleID=3455

Basically, NTFS is more secure because the index is held in two locations and because files are generally less fragmented, thus allowing easier recovery.

In my experience of FAT 16/32 and NTFS 4/5, I never have had "lost clusters" under NTFS wheras almost every time I run a windows 98 system, I find lost clusters. Lost clusters often means lost data - this is bad. NTFS doesn't lose data in the same way - this is good.
Well yes, thank you, but links are all over the place and easy to find: I was rather hoping that you could explain, from your own experience and in your own words, exactly what the difference was, rather than point to a definition of each.

Odd but I don't ever remember actually "losing" clusters though it is a term often used when the subject is mentioned. I was under the impression that a cluster is a logical, not a physical unit and it does seem therefore, to my way of understanding it at least, that losing one would be impossible in the normal definition of "lost". But of course, I don't know.

Do you mean that the term "lost" in this case, simply refers to those clusters that are marked by the FAT, or NTFS, as being in use when indeed they are not? And aren't they usually caused by the interruption of a process of some sort, for example, when saving a file. If the action of saving is interrupted in some way, some clusters will be "populated" by data but because the process wasn't completed, the FAT or NTFS won't know about it all because it was never "informed" that the process was complete. Therefore, there are "file fragments" left lying around in sectors, on the drive. And aren't those are easily removed, notably with a check disk utility of some sort?

And for my own information, could you confirm that the default setting with NTFS is such that all such file fragments are deleted automatically when the check disk utility runs, whereas in FAT it is a user setting? In which case, unless the setting was changed, it's unlikely that many fragments in NTFS would ever be seen, even though they are just as likely to exist as they are in FAT? Is that right or have I completely misunderstood the issue?

Bascilly I'm still very confused as to why you talk about corrupted FATs in relation to digital cameras and memory cards. I really don't understand that and your explanation, in layman's terms, of how they occur, or of anything else I've misunderstood here, really would be of interest to me, and I believe, to all who might read this.

Thanks in advance.

Rhys
09-28-2004, 11:45 AM
Ok. I'll try to simplify it a bit more:

The FAT system is error prone because of the way it's designed and implemented. It was tables containing links to other tables containing links to yet more tables of where the data is actually held.

Any corruption on any of those tables will result in lost data - from losing a cluster, a sector or indeed an entire disk. The primary FAT table is held on track 0 of the disk

With the NTFS system, the data tables are replaced by a database. Not only this but there is a backup of the database.

I've had entire disks go bad under FAT 16/32 and found the only way to recover them was to format to eth-0 and then back to FAT 16/32.

Let's just say that the NTFS system is less prone to error; less prone to lost data and allows use of larger disks.
FAT 16 maxes at 2gb
FAT 32 maxes at 38gb
NTFS5 has no max that I've encountered.

judge9847
09-28-2004, 01:07 PM
... OK, so your point is that the problems with the SanDisk that are at the heart of this thread are caused by WINDOWS or rather by the manufacturers of the CARD using a DOS/WINDOWS FAT system when they should be using WINDOWS NTFS. I get it.

On top of that you seem to be saying that each MEMORY CARD has a WINDOWS FAT system which can cause file fragments all over the place and which then give rise to the problems described here. Which in turn strikes me as strange because I thought, in my ignorance, that FAT or NTFS was for magnetic media whereas a card is flash memory of some sort. Chalk and cheese, really. Or so I thought ...

And how does a card connected to a Mac behave if it's a DOS/Windows issue? Doesn't seem to me to compute ... gee, I wish I really understood these things :rolleyes: