----------------------------------------------------------------- STACKER NOTE STACKER NOTE CHECK I/O ACCESS DENIED ERROR 27 (STACKER 4.0) (Applies to Stacker 4.0) STAC FAX 4706 (04-08-1994) ----------------------------------------------------------------- BACKGROUND If you receive this error while checking your Stacker drives, you may have corrupt data in the File Allocation Table (FAT). The errors could be caused by: -Bad sectors on the underlying physical drive -An errant program that writes data incorrectly and destroys part of the File Allocation Table (FAT) -A program that incorrectly uses Expanded Memory Specification (EMS) SOLUTION To correct this error: - Determine which areas of your hard drive have been damaged - Correct the damaged, unreadable areas Determine which areas of your hard drive have been damaged The first step is to clean boot your system and remove the hidden, system, and read-only attributes from the STACVOL file. Determine whether Stacker is preloading before CONFIG.SYS. If you are not sure, open the CONFIG.SYS file by typing ED /C . Look for the Stacker lines in the file. If one of them is similar to the line below, then Stacker does NOT preload: DEVICE=C:\STACKER\STACKER.COM If you do not see a STACKER.COM statement, and you have access to your Stacker drives, then your Stacker version is preloading. Select the appropriate procedure below. IF STACKER PRELOADS 1. From the DOS prompt type: STACKER . 2. Examine the drive map that is displayed and locate the damaged drive. The line will look something like this: Drive C was drive C at boot time [ D:\STACVOL.DSK = 123.4MB] Note the drive letter and file name in brackets. In this case it is D:\STACVOL.DSK. This drive letter is the uncompressed boot drive. 3. Restart your system. Press the F5 key when you see the message "Starting xx-DOS...". 4. From the prompt, type: ATTRIB -H -R -S drive:\STACVOL.xxx where drive:\STACVOL.xxx is the drive and file name you noted in step 2. IF STACKER DOES NOT PRELOAD 1. From the DOS prompt type: STACKER . 2. Examine the drive map that is displayed and locate the damaged drive. The line will look something like this: Drive C was drive D at boot time [ D:\STACVOL.DSK = 123.4MB] Note the drive letter and file name in brackets. In this case it is D:\STACVOL.DSK. This drive letter is the uncompressed boot drive. 3. Change to the DOS directory of the drive you noted above. Copy ATTRIB.EXE from the DOS directory of drive C to the DOS directory of the uncompressed boot drive. 4. Restart the computer using a system disk in drive A. Your Stacker drives will not be mounted. 5. Change to the DOS directory on drive C. 6. From the prompt, type: ATTRIB -H -R -S drive:\STACVOL.xxx where drive: is the drive where CHECK originally reported the error. Correct the damaged, unreadable areas Standard disk repair utilities such as Norton Utilities Norton Disk Doctor, PC Tools DiskFix, or SpinRite, can detect the damaged areas and correct them. Run your disk repair utility from the floppy disk drive. This ensures that you are running an uncorrupted version of the utility. Also, if you do a clean boot, the utility may not be available from your hard disk. 1. Run the disk repair utility on the damaged drive. This is the drive letter you used when running the ATTRIB command in the previous procedure. Allow it to repair any defective areas on the disk. 2. Remove all disks from the floppy drives and restart the computer. 3. Run the Stacker command CHECK /F. If there are no errors, the drive is repaired, and you can resume normal use of the drive. IF YOU STILL HAVE ERRORS If you still cannot repair the Stacker drive, there are two additional procedures you can try before resorting to removing the damaged drive and starting over: removing write protection, and removing the /EMS parameter. Removing write protection To remove write protection, follow the procedure below, where "x:" indicates the drive letter of the compressed drive: Type: CHECK /=w x: Warning: This command produces a message stating that the read- only status of this drive has been cleared. Do not interpret this to mean that you can resume normal use of the drive; doing so prematurely will result in data loss. Instead, you must complete the steps outlined below. Never use CHECK /=W to remedy other write-protect situations. Run CHECK /F again. Follow the instructions to repair the drive. When prompted to perform a disk surface test, respond "yes," and delete the damaged files. When CHECK reports no more errors, the drive should be fully repaired. If errors persist, disable Stacker's use of EMS. Removing the /EMS parameter Persistent errors indicate that the drive's FAT is damaged. Some programs use expanded memory improperly. A program’s undisciplined use of the EMS page frame can corrupt the FAT. If this is the case, you can prevent further corruption by disabling Stacker's use of EMS memory. 1. Type ED /I . 2. Look for a line like this: /EMS 3. Delete the line, press CTRL-Z to save the file and exit. 4. Restart your system, then type CHECK /F to complete repairs. If errors persist, the drive's FAT may be damaged beyond repair. The only solution is to delete the drive with the damaged FAT and start over. Deleting the damaged drive and starting over 1. Back up the data on the drive. 2. Run the Stacker command REMOVDRV drive: to delete the damaged drive. 3. Restart the computer. 4. Compress the drive again and restore from backup. ----------------------------------------------------------------- Copyright 1994 Stac Electronics