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ABOUT PqRP - The PqRP de- mystified - PqRP FAQ - RFC
PowerQuest PqRP FAQ - July 24 2003 - Joep
** About PqRP: ** * The problem: As SOON as PartitionMagic (from now on: PM) starts it's operation on a partition it will 'edit' the partition table and replace the byte that descibes the type of partition (so FAT (06h), FAT32 (0Bh) etc ...) to byte value 3Ch. PartitionMagic and all PQ products will display a 3Ch type partition as PqRP or PQFlex type partition. A PqRP type partition can NOT be accessed by Windows operating systems (Possibly Linux can). Only when PM completed the operation it will replace the 3Ch value by the proper value describing the partition type. Therefore a PqRP type partition ONLY means that PM was performing a task on this partition and it didn't get the chance to finish it. It does NOT say anything regarding the amount of damage in the partition. SOMETIMES changing the 3Ch value in the partition table to the proper partition type will help you gain access to the partition again. It highly depends up on in which stage PM was, if contents of the partition are still intact. For example PM starts by checking the partition (can sometimes be up to 10% of total progress), and when it crashes during this stage, where no 'juggling' with data took place yet, editing the partition table alone may be enough to gain access to the partition again. Now the whole purpose of 'flagging' the partition this way is to prevent tools like scandisk 'touching' this partition or to prevent you writing to it. Running scandisk on a damaged partition may very well render recovery of data impossible. * The answer(s) This group (comp.sys.ibm.pc.hardware.storage) is frequently visited by Svend Olaf and he nailed down the PqRP problem pretty well (probably he's the person who knows most about it aside from some PQ developers), he even studied it to such a degree that he was able to write a tool (PqRP.exe) that allows you to clasify the amount of damage within the PqRP partition. His advise often is to leave the 'flag' as it is (3Ch - PqRP) and my guess is that he advises this because of the same reason the PqRP mechanism exists in the first place: as long as tools or Windows doesn't recognize a partition they will not touch it i.e. will not make the damage worse than it already is. This is good and solid advise! PQ technical 1st line technical support does not have a clue what_so_ever of what to do when the Ptedit trick (see below link for PQ KB article) doesn't work, they just follow the same knowledge base article that is publically available at the PQ support site (see below). They will refer you to the manual where it is advised to create a backup before running PM. (NOTE: If you DO edit the partition table for a FAT16 partition and you find a 'DYN_ROOT' when accessing it, I may be able to help to fix this - I have written a tool that will fix this automatically - available up on request only - I will first ask for a partinfo output, see below) The only chance you have now: - try the Ptedit trick (see link to PQ KB article below). Make sure to write NOTHING to the partition, and prevent ALL programs from writing to or touching the partition! Do NOT run Scandisk or NDD! Safest is to boot a DOS diskette and try to READ the partition and verify you can access it, access subfolders and maybe try to open a text file. Under NO circumstances write to the partition until you have verified all is well! If data is only partially available, copy the data you can access to ANOTHER physical disk or removable disk. - is getting Svend to help you, we all have been witnesses that he frequently/always DOES recover PqRP partitions intact (at least of the FAT/FAT32 type). Svend will ask for a findpart output (see below). - or if you do not want to wait for that try a READ-ONLY commercial data recovery tool to copy the data to ANOTHER disk. If such a tool succeeds in recovering your files (verify them FIRST), you can then delete the PqRP partition and recreate and reformat it. Concentrate on recovering user data (copying an entire Windows installation and then expecting it to boot is useles). If you decide to repartition the drive after you have recovered your data and find PartitionMagic will not run because of partition table errors see procedure below. * Web addresses: PowerQuest PqRP KB article : http://www.powerquest.com/support/primus/id3851.cfm PowerQuest's Ptedit program : ftp://ftp.powerquest.com/pub/utilities/ptedit.zip PowerQuest's Partinfo program : ftp://ftp.powerquest.com/pub/utilities/partinfo.zip Svend's PqRP program : http://inet.uni2.dk/~svolaf/utilities.htm Svend's Findpart program : http://inet.uni2.dk/~svolaf/utilities.htm Joep's website (for help with DYN_ROOT): http://www.diydatarecovery.nl * Procedures: ====================================== PQ KB article: Solution: Fixing a PQRP with PTEDIT To fix a PQRP with PTEDIT: 1. Run PTEDIT. 2. Locate the PQRP (partition type 3C). If the PQRP occurred on a logical partition, click "GoToEPBR" to locate the correct partition. 3. Click in the "Type" field associated with the 3C partition. 4. Click "Set Type." A list of available partition types is displayed. 5. Select the appropriate partition type (e.g., FAT32 if the partition type was FAT32 before the PQRP, etc.). 6. Save the changes and exit. If the system does not boot properly at this point, run a directory listing (DIR) on the drive and make sure there are no "DYN_ROOT" entries. A "DYN_ROOT" indicates that the original root directory has been relocated but can, in most cases, be restored. If the directory listing appears as random ASCII code or unrecognizable characters, the partition is likely corrupt and cannot be recovered. Note: If the root directory appears as a DYN_ROOT, do not SYS the drive. Modifications made to the drive while in this state can reduce the probability of recovery. Contact PowerQuest Technical Support for further assistance. ====================================== ====================================== Running partinfo: 1. Go to a true DOS prompt (not a Windows command prompt). 2. Change to the directory that contains PARTINFO.EXE. (For example, if you want to run PARTINFO from the PartitionMagic rescue diskettes, insert the first rescue diskette and change to the A:\ drive.) 3. Type PARTINFO LPT1 (to send the results to the printer) or PARTINFO A:\PARTINFO.TXT (to save the output as a text file named PARTINFO.TXT to the root directory), and then press Enter. ====================================== ====================================== Running Findpart: The report can be written to a file. Add the filename to the command line. File extension must be .txt. To append to current report file, use +filename. Example: findpart all fp.txt [enter] ====================================== ====================================== Running Svend's PqRP program Usage: Pqrp disknumber [logfile] [files] [original] Disks are numbered from 1. Log file extension must be .txt. If 'files' is entered, a file listing is printed to the file pqfiles.txt. The 'original' option checks the partition at the Pqrp location without adjustments. This version works with disks with a 240 heads or 255 heads BIOS translation. Note that the settings should not be changed after the disk has been partitioned. ====================================== ====================================== Running PartitionMagic while partition table errors are present ONLY ignore partition table errors if it is your intention to delete the partitions on the 'BAD' disk. Under NO other circumstances partition table errors should be ignored! PartitionMagic may fail to run if partition table errors are present (Disk is shown as 'BAD'). You can tell PM to ignore partition table errors so you can at least delete partitions from your harddisk (and by doing so getting rid of partitions + partition table errors). To do so run the DOS version of PartitionMagic with the /ipe switch: pqmagic /ipe [enter]. ====================================== * How to prevent dataloss as a result of a PqRP - BACK UP YOUR DATA! - Do NOT assume PM is hanging when it seems to have stopped displaying progress! Toggle the NUMLOCK key and see if the LED toggles on and off, if so leave PM and let it continue. (I have reproduced situations where it took FIVE days to merge 2 partitions!) - Do NOT perform resizes or merging when the partition(s) is/are almost completely filled up! - Do NOT merge a 'used' partition with an EMPTY one: instead delete the empty partition and resize the used partition * Final note(s): - Suggestions for a PqRP FAQ are welcome - remember you will hardly find notice posts how wonderful PM resized partitions. Almost evry post you'll find will be about a problem of some kind. This is NOT because PM tends to make partitions F.U.B.A.R., it is because problems will cause people to seek help and post a message asking for it. I no use PM for 4,5 years (frequently) and it has never let me down (knock on wood). Also I have worked for PQ 3rd line support and often PqRPs were caused by pure stupidity that some people are willing to admit, like tripping over power cable - power cut - cat jumped on keyboard hitting CTRL+ALT+DEL - PC fell from table etc.. (I am NOT joking or making this up!) * Disclaimer: Use this information ON YOUR OWN RISK! -- Kind regards, Joep |
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