Image Recovery

Background on Z-A Image Recovery

	Will it recover images from my digital camera X?
	With the exceptions listed on the, the honest answer is: "We have no foggiest idea".

	Prerequisites
	Image recovery process was designed to get all the files of any type it knows off any accessible media. That means you need two conditions fulfilled: File type (format) must be known Media (typically a flash card) must be accessible If your digital camera (or the other media, see below) matches these criteria, you will most likely get your images back. If you can't get the results, this is most likely due to the problem with the above requirements.

	Identifying common problems
	If the flash card (media) is inaccessible you will be certainly aware of that. This is when you cannot find your memory card in the list, or the program hangs/crashes when attempting to scan the media. You need your memory card to be presented as a logical drive (with a drive letter like D: or E:) in your system in order for ZAR to read it.If your camera does not normally show its contents as a logical drive, you will need a card reader device. You may get it from your friend if you don't have one, as we found (to our surprise) that most people who take digital photography seriously have one anyway. Generally, using a card reader device under Windows 2000 or XP should solve nearly any problem you may have accessing your memory card.If you see that ZAR accesses the media successfully but still no images are recovered, there is a chance that file format is not recognized. First of all check to see if your particular camera model is listed as incompatible/irrecoverable. If it is, we cannot help you. This means we have already worked with this camera and were unable to provide any solution (i.e. bad things do happen). The incompatible devices list is sometimes revised, but that does not happen often.

	If you feel something is wrong
	There are just too many cameras out there for us to test them all. They use different file formats and different variations of the same format. We rely on you to get samples of the files so we can adjust the program to understand the particular format or variation. If you feel the data can be recovered but ZAR fails, feel free to submit your request via with the following details: Exact camera model Exact operating system in use (Click Start -- Control Panel -- System to see full details). The details on the access method (card reader used or not).

	The compatibility list
	The camera compatibility list is created and maintained based on your feedback. If you don't see your camera listed, this means no one had tried it yet, or no one emailed us their results. So rather than asking us if ZAR will work with your camera you'd better try it yourself. Remember that most likely we do not know it anyway.

	Image recovery and exotic devices
	ZAR can also be used with the devices other than a digital camera. For example, one of our users reported a successful ZIP disk recovery. However, the following limitations apply: No access method for floppy drives - the disk I/O library is specifically designed to ignore them. No access method for CDs - the disk I/O library does not know how to handle them (a while ago there was an idea that implementing a CD reader would be nice, but it died because of perceived lack of user interest). Attempting to get all images off the hard disk is probably not a good idea. There probably will be just too many of them. If you ever try image recovery in such a fashion, make sure images are being saved to another hard disk, otherwise an infinite loop will occur or the disk ends up filled with copies of the same image.

CHKDSK: "RAW filesystem" message

	Symptoms
	Sometimes a damaged volume may look like it lost its filesystem type. Various error messages may appear, most common beingThe volume X: is not formatted. Do you want to format it now? The disk in drive X: is not formatted. There was an error accessing drive X:. The disk is not formatted. Also a CHKDSK tool will complain that it is unable to perform a RAW filesystem recovery. The type of the filesystem is RAW. CHKDSK is not available for RAW drives.

	How to recover data from RAW filesystem
	ZAR data recovery software will in most cases handle such a situation pretty well. Please refer to the tutorial for step-by-step instructions.

	Technical details
	To know how to deal with it, we need to discuss the basics first. The filesystem type is recorded at least in two separate places In the partition table (MBR, sometimes referred to as a legacy-style partition) or in the LDM database (when dynamic disks are used). In the volume boot sector. Three significantly different combinations are thus possible. Both partition table and volume boot sector provide consistent information about the filesystem type. This is how the things are supposed to be when the volume is online and operational. Only one of these places contains proper information, or the information is contradictory (e.g. partition table lists the volume as NTFS, while the boot sector indicates it is the FAT32). Neither partition table nor volume boot sector contains filesystem type information (the partition table will in this case indicate the special filesystem type of zero, i.e. unused volume). This can happen during normal operation and is pretty legal configuration state. It appears when you create a volume (e.g. using Disk Management applet) but do not format it at the same time. You can even assign a drive letter to this unformatted volume, as illustrated below (notice the underlined "H:" drive which has no filesystem type defined). If the volume filesystem type information is unavailable, attempting CHKDSK against the volume will result in the following message: The type of the filesystem is RAW. CHKDSK is not available for RAW drives. Sometimes, the volume fails in such a way that it becomes RAW. In most cases the failure will be associated with a sudden reboot (per power failure or the STOP error). Several causes are possible: partition table, LDM database, or the volume boot sector corruption, or (on the NTFS volume) when certain records in both MFT and MFT mirror are damaged beyond easy recognition.

	"RAW filesystem" recovery expectations
	The data recovery should not be complicated because the volume location info is still available. Be advised that some arbitrary filesystem type may be associated with the volume when you attempt to identify it amongst the list of the available volumes. Notice the highlighted volume - it is the same H: volume featured in the earlier screenshot. It has the correct size (128MB) and the correct on-disk location (starting at 200+40+40 = 280MB from the start of disk), but the filesystem type of "Large FAT16" is not a good bet because the volume is in fact NTFS - the filesystem type information in the LDM database got corrupt (yeah, I know because I did it in purpose). This fact will be later discovered  and the appropriate decision will be made to treat the volume as NTFS, and in this test case an exact recovery is ultimately achieved. In a real world case, the raw partition recovery expectations vary depending on the damage profile and locality. Overall, I'd expect a good yield. Exact raw partition recovery is possible if the damage is confined to the boot sector(s) and/or partition table (however there is no easy way to tell if it is). Suggested course of action is thus as usual: to downloadnd try it.