CN.RNA@forsythe.stanford.edu (Richard Anderson) (03/28/90)
In article <8603@lindy.Stanford.EDU> I wrote of problems with a 2-drive system in which a spare copy of the root partition is on the second drive. I had trouble (I assumed) because my second drive doesn't have a swap partition the same size as that on the first drive. Here is a summary of the responses I got together with my reactions. I appreciated the timely feedback. - ------------------------------ From edler@jan.ultra.nyu.edu (Jan Edler) > Here at NYU we've never felt the need to keep a spare root partition on > the second (or third) drive of a machine. There are several reasons > for this: > 1) A machine with only 70MB drives doesn't really have a lot of space > to waste, [stuff deleted] Thank you Jan. I will take your advice once the files in my hd1g partition reach a size were I need more space. - ------------------------------ From ibmsupt!ibmpa!ericm@uunet.UU.NET (Eric Murray) ~ you can have anything you want in the way of minidisk partitions- ~ as long as the partition info gets written out to disk. ... ~ after you create your minidisks, use the 'write' option to ~ force the info out to disk. if you create your own, make sure you ~ use contiguous inode numbers- i usually to one of the 'standard' ~ partition sets, write down the inodes, then delete then and create ~ my own, using the same inode numbers. ~ [ stuff deleted ] ~ aha! i see what's going on: when you re-did your minidisks, you ~ didn't re-run mkfs/newfs. if you had, you would have lost your ~ data. you also wouldn't have confused fsck. make sure you ~ newfs the partitions after re-doing the minidisks (after ~ having backed up everything on hd1, of course). Actually, I did do the newfs, but may have neglected to give the minidisk write command. That could explain why my data got clobbered. Bear in mind that I created the subdirectories that dissapeared *after* doing minidisk/newfs. ~ >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? ~ ~ no. what book was that? In "Unix System Administration Handbook" by Evi Nemeth, Garth Snyder and Scott Seebass (Prentice Hall, 1989), on page 197 it is written: Whenever the system has the partition information stored in the driver, it is difficult to change the default partitions. In addition, the device driver has only one table of partition information for each type of drive that it controls. Therefore it is hard to ask that driver to handle two drives of the same type with different partition layouts. In general, even if this were simple to do, it is not advisable. It's too easy to forget a nonstandard partitioning and clobber the whole disk. Apparantly the above caution does not apply to the IBM RT. [ more stuff deleted ] ~ > Does the very existence of hd1b cause the system ~ >to want to use it for swap space, ~ ~ no, unless your kernel has it configured AND there's an entry ~ for it in /etc/fstab. you can get by with just the fstab ~ entry by using /etc/swapon ('/etc/swapon /dev/hd1b'). ~ you can tell if your kernel wants to swap on hd1b by looking ~ at the config messages at boot time, or by running /etc/dmesg ~ to see the last 200 kernel printfs. ~ ~ > and if so, does the swapper assume ~ >that hd0b and hd1b are the same size? ~ ~ no. that's why the entry in /etc/fstab, to tell everyone ~ how big it is. - ------------------------------ From Salvatore Saieva <SLVQC@CUNYVM.BITNET> ~ What books do you recommend? I'm having a hell of a time dealing with ~ the doc's that came with the system (they're photocopies and in pretty ~ poor shape). In addition to Nemeth, et. al., above, I am relying heavily on the IBM AOS 4.3 System Administration Guide which came with my copy of AOS 4.3. It seems to be the ultimate authority on the specifics of how AOS 4.3 on the RT works. "Unix System Administration" by David Fiedler and Bruce Hunter (Hayden, 1986) gives some additional information, but it is written more with System V examples. Finally, one of my co-workers went to a USENIX tutorial on UNIX 4.xBSD Systems Administration, given by Evi Nemeth and Rob Kolstad. The handouts from it are very useful. ~ Have you come across any FTP sites that host or archive AOS/RT ~ specific files? I'd really like to hear what you have done to ~ get started using this machine. I'd love hear about FTP sites for AOS/RT files myself. Maybe someone from the newsgroup will respond.