Message-ID: <01FD6EC775C6D4119CDF0090273F74A4022020@emwatent02.meters.com.au> From: "da Silva, Joe" To: "'opendos AT delorie DOT com'" Subject: SStor/FAT recovery? Date: Thu, 5 Apr 2001 20:34:56 +1000 MIME-Version: 1.0 X-Mailer: Internet Mail Service (5.5.2448.0) Content-Type: text/plain Reply-To: opendos AT delorie DOT com OK, here's a tricky one ... I was "playing around" with some bits and pieces and had an unexpected failure of the MB (yep, there was smoke! ;-) ... This failure corrupted the hard disk, wiping the MBR/PT, boot sector, FAT1, and half of FAT2. I have rebuilt the MBR/PT, the boot sector and sort-of rebuilt the FAT, using what remained of FAT2 and the root directory information (I built cluster chains from the starting cluster information in the root directory, as if the disk had no fragmentation and no spare clusters in the first half of the disk). The disk is/was DR-DOS 6.0, with just a few necessary files in the normal disk space, the bulk of the disk was a SSTOR compressed "drive". Now, I can easily replace any files in the normal disk space if they aren't exactly right, as they are (were) just a few O/S files. My main concern therefore is to ensure that the SSTOR "drive" *is* exactly right ... Well, that's the background ... now to the specific problem. With the loss of half the original FAT information, I don't know what clusters were previously marked as "BAD". The starting cluster of the SSTOR file (SSTORsomething.SWP, I think) is known, from the root directory information. The second half of the cluster chain is known, from the remainder of FAT2. However, the total number of clusters I have chained together for the SSTOR file is greater, by 6 clusters, than the file size information from the root directory indicates. I'm sure this must be due to clusters, that were previously marked as "BAD", that are now linked in the FAT chain. So ... is there any way to determine, from the internal SSTOR file structure, what clusters (or whatever) have actually been used by SSTOR for data storage? In other words, is there anything equivalent to a FAT within the SSTOR file, that might be used to identify either "BAD" clusters or expendable clusters? OK, before you ask : No, there are no defects listed on the drive sticker, and no, none of the sectors or clusters presently give read errors. So I can't identify the "BAD" clusters that way ... Oh, and please, no smart-alec remarks about backing up! Joe.