Path: utzoo!attcan!uunet!tut.cis.ohio-state.edu!ucbvax!pasteur!agate!shelby!lindy!news From: CN.RNA@forsythe.stanford.edu (Richard Anderson) Newsgroups: comp.sys.ibm.pc.rt Subject: Non-standard partition sizes, files lost Message-ID: <8603@lindy.Stanford.EDU> Date: 21 Mar 90 23:07:17 GMT Sender: news@lindy.Stanford.EDU (News Service) Lines: 81 I have an RT 6150 with two 70E hard disks. I am running AOS 4.3. Since it is for me a new computer, I initially was only using the first hard disk (hd0). Once I had mastered essential stuff (like making backups), I moved on to the creation of a new file systems on the second hard disk (hd1). Since I am mostly teaching myself Unix system administration with the help of a few good books, I have been prone to trial and error experimentation. During this experimentation, the contents of the filesystem stored on hd1g mysteriously dissapeared. Also, I kept getting an fsck error message I had trouble deciphering that read: SUMMARY INFORMATION BAD (SALVAGED) I suspect the cause of my trouble was due to the fact that I partioned hd1 into sizes that were both non-standard and different from the partions sizes of hd0. I used the minidisk command to set up the first disk as a standard root drive. hd0a is root, hd0b is swap space, hd0g holds /usr. I set up the second disk with standard root partitions also, but then deleted and re-created hd1b and hd1g, so I could create a larger hd1g. I have used hd1a for a dd backup of hd0a. I also found out by trial and error that hd1b had to be a swap partition if I ever wanted to boot from hd1 (if I ever need to repair hd0a). standard root delete hd1b delete hd1g create hd1b 32743 11025 swap create hd1g 32744 97735 00 512 Byte Blocks --------------- hd0 standard root name iodn size start type ------ ------ ------ ------- ------ boot 32736 105 140 ipl hd0a 32737 32585 245 00 hd0b 32738 33565 32830 swap hd0g 32739 75195 66395 00 hd1 customized name iodn size start type ------ ------ ------ ------- ------ boot 32741 105 140 ipl hd1a 32742 32585 245 00 hd1b 32743 11025 32830 swap hd1g 32744 97735 43855 00 The above partition structure for hd1 did not work properly. It appears that some parts of the Unix software recognize the sizes of the partitions, whereas other parts (perhaps the swapper daemon) thought that both disks were partitioned the same. Whatever the cause, however, what happened is that all the subdirectories and files on hd1g were mysteriously deleted at some point from one day to the next. I cannot rule out human error, but it seems most likely that the swapper daemon was at fault. Hardware diagnostics were run by an IBM service rep, but no defects were found. hd1 was therefore re-partitioned to the standard root configuration. Both hard drives now have exactly the same partition sizes. So far, so good. No data has been lost from hd1g since the re-partitioning. So, does anybody have any suggestion/advice to offer? Should I have trusted the author of one of my books who warned me to set up both my disks the same? If so, why is there a "standard source" option under minidisk? Does the very existence of hd1b cause the system to want to use it for swap space, and if so, does the swapper assume that hd0b and hd1b are the same size? Did my use of dd cause any problems? Sorry for the length of my query. Hope the feedback I get will be educational for the newsgroup. Thanks. -- Richard Anderson cn.rna@forsythe.stanford.edu Systems Department, Green Library Stanford, CA 94305-6004 (415) 725-7932