demasi@paisana.UUCP (04/03/87)
Hello Folks,
I've seen some questions along this line in this group, so I thought
I'd give it a shot. I'm S/A on a 3b2/400 running Sys V.2.0.4, and for
some reason am having troubles partitioning the disks (2*72M) to the
recommended 23Meg limit for file systems. I'm trying to accomplish
this by using the makefsys command on the disk partitions in single
user mode with the file systems unmounted. (The alternate method,
doing a full restore from the core packs is impractical since the
machine is already in production, and I didn't know about the size
restrictions when I started this project)
Things go well when I recreate /usr2 at the smaller size, but makefsys
returns a read error when I try to create the other file systems on
the same disk. Since I can create a file system in the same place as
where one already existed, I imagine that I am simply leaving out a step
to prepare the disk partition for a makefsys (or something close to
that.) Everybody I have spoken to so far says that it must be possible
to repartition without doing a full restore, but nobody quite seems to
know what the missing step is. Also, since I remade /usr2 to the
suggested size, backups have been going awry in that a backup of the
root system does not stop at the root system but continues up the file
tree (ie into /usr and so forth.)
Any ideas folks?
(I really don't want to do a full restore at this point)
--
Michael C. De Masi - AT&T Communications (For whom I work and not speak)
3702 Pender Drive, Fairfax, Virginia 22030 Phone: 703-246-9504
UUCP: seismo!decuac!grebyn!paisana!demasi
"No matter where you go, there you are" - Buckaroo Banzaicwd@cuae2.UUCP (04/04/87)
Read the "Hard Disk Partitioning" Section in the System Administrator's Guide (in Administrative Tasks major section) and look at the manual page for /etc/fmthard (in the SA Reference Manual). Also, take a look at the "sysadm partitioning" command. You'll get the idea. Chris Donahue AT&T Info. Sys. Customer Systems Engineering
authorplaceholder@gorgo.UUCP.UUCP (04/05/87)
Chris Donahue writes: >Read the "Hard Disk Partitioning" Section in the System Administrator's >Guide (in Administrative Tasks major section) and look at the manual >page for /etc/fmthard (in the SA Reference Manual). Also, take a >look at the "sysadm partitioning" command. You'll get the idea. I'll go one step further... The fmthard command is necessary since the 3B2 disk partitioning is actually determined by vtoc stored on the disk. The fmthard command writes a new vtoc onto the drive. This *always* cremes the data on the drive, so take care. Note also that the filesystem boundaries need to occur in correctly timed offsets on cylinder boundaries or performance will suffer. "sysadm partitioning" knows about this necessity and will compensate appropriately. Hope this helps, Steve Blasingame (Oklahoma City) bsteve@gorgo.att.com
jgy@hropus.UUCP (04/06/87)
> Chris Donahue writes: > > >Read the "Hard Disk Partitioning" Section in the System Administrator's > >Guide (in Administrative Tasks major section) and look at the manual > >page for /etc/fmthard (in the SA Reference Manual). Also, take a > >look at the "sysadm partitioning" command. You'll get the idea. > > I'll go one step further... The fmthard command is necessary since the 3B2 disk > partitioning is actually determined by vtoc stored on the disk. The fmthard > command writes a new vtoc onto the drive. This *always* cremes the data on ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > the drive, so take care. Note also that the filesystem boundaries need to > Not true, it does not touch the data on the disk, only the information describing how to get to the data, rather like losing your inode area. But it can be reversed with more ease!
leonard@acf4.UUCP (04/06/87)
I too, am running sysV, r2.0.4. However, I suggest getting your hands on a copy of the release 3 System administrator's guide,(which has been expanded from the release 2 manual) and reading section 5 (File admin) of the first part, and sections 4 & 5 of the second part. Shanna Leonard ARPA: leonard@acf4.nyu.edu
bsteve@gorgo.UUCP (04/08/87)
Chris Donahue responds: >Not true, it does not touch the data on the disk, only the information >describing how to get to the data, rather like losing your inode area. >But it can be reversed with more ease! This is correct... the clue is to be careful to SAVE a copy of the old vtoc format OR spend lots of time guessing. I have had old drives with a marginal sector right on the vtoc and have successfully restored the vtoc data from time to time and kept right on truckin on the old drive. Here is an example of an old vtoc which splits a 72MB drive into 2 parts: * Partition ID Flag Start Sector Size in Sectors 05 0 01 0 0 06 0 01 0 148896 07 0 01 0 198 08 0 00 198 74250 09 0 00 74250 74448 10 0 01 0 0 One might use only partition 8 for live data, reserving partition 9 for future use. Later when partition 9 becomes used it might be desirable to split it into 2 parts as is shown below. * Partition ID Flag Start Sector Size in Sectors 05 0 01 0 0 06 0 01 0 148896 07 0 01 0 198 08 0 00 198 74250 09 0 00 74250 37224 10 0 00 111474 37224 Here we've used partition 10 also in reallocation of the drive while preserving the data in partition 8. Meaning of flags are as follows: 00 = mountable 01 = non-mountable 10 = read-only For safety's sake, ALWAYS save the existing vtoc data using /etc/prtvtoc before making ANY changes and (of course) have a good backup. Something in the form: # /etc/prtvtoc /dev/rdsk/c2d1s0 >/etc/vtoc/c2d1s0 Then copy the text file and make changes... # cp /etc/vtoc/c2d1s0 /etc/vtoc/whatever Then to update the drive: # /etc/fmthard -s /etc/vtoc/whatever /dev/rdsk/c2d1s0 If you have messed up the data somehow you can get back the old vtoc data by typing: # /etc/fmthard -s /etc/vtoc/c2d1s0 /dev/rdsk/c2d1s0 For more concise information regarding this procedure and about creating filesystems on the new partitions read the documentation as this can also be a dangerous procedure. One can re-partition a drive using the menu-driven simple administration, but it is not always guaranteed that the partitions will fall where you want them and prevent you from clobbering existing data, particularly if the drive was not initially partitioned using the simple- administration menus. Hope this helps, Steve Blasingame (AT&T Oklahoma City) bsteve@gorgo.att.com ihnp4!gorgo!bsteve
mdb@laidbak.UUCP (04/18/87)
> [Chris Donahue] > ... > partitioning is actually determined by vtoc stored on the disk. The fmthard > command writes a new vtoc onto the drive. This *always* cremes the data on > the drive, so take care. Note also that the filesystem boundaries need to > ... The 3B2 /etc/fmthard command replaces the VTOC (partition map) of a hard disk. It does not damage the contents of the partitions. Note that /etc/fmthard does, however, make a disk non-bootable; it zeroes the VTOC words which point at the second-level bootstrap. Use "/etc/newboot /lib/lboot /lib/mboot /dev/rdsk/c-d-s7" to reinstall the bootstrap. Mark Brukhartz Lachman Associates, Inc. ..!{ihnp4, sun}!laidbak!mdb