Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site dice.UUCP Path: utzoo!linus!philabs!cmcl2!seismo!mcvax!ukc!edcaad!dice!scott From: scott@dice.UUCP (Scott Williamson) Newsgroups: net.unix-wizards Subject: DEC R80 disk partitions (help wanted) Message-ID: <127@dice.UUCP> Date: Thu, 25-Oct-84 08:24:19 EDT Article-I.D.: dice.127 Posted: Thu Oct 25 08:24:19 1984 Date-Received: Sat, 20-Oct-84 07:02:57 EDT Organization: Ferranti Cetec Graphics Ltd. Edinburgh, Scotland. Lines: 77 [..........] We have a Vax 11/730 running 4.2bsd. Mass storage on this machine consists of a Fujitsu Eagle and a DEC R80. My problem is trying to understand how the disk partitions have been set up. (I took on the role of system manager about 3 months after first encountering Unix.) Our root filesystem is on the Eagle with swap space in the 'b' partitions of both disks. I am having no problems with the Eagle but have encountered some difficulty with the R80. The relevant entry in /etc/disktab is as follows: rb80|RB80|DEC R80 on 730 IDC:\ :ty=winchester:ns#31:nt#14:nc#559:\ :pa#15884:ba#8192:fa#1024:\ :pb#33440:pc#242606:\ :pg#82080:bg#4096:fg#512:\ :ph#110143:bh#4096:fh#1024: Looking at the source of the device driver (/sys/vaxuba/idc.c) there seems to be agreement with the above. }, rb80_sizes[8] ={ 15884, 0, /* A=cyl 0 thru 36 */ 33440, 37, /* B=cyl 37 thru 114 */ 242606, 0, /* C=cyl 0 thru 558 */ 0, 0, 0, 0, 0, 0, 82080, 115, /* G=cyl 115 thru 304 */ 110143, 305, /* H=cyl 305 thru 558 */ However, using diskpart(8) to calculate default partition sizes for it gives the following results: % diskpart -d rb80 rb80:\ :ty=winchester:ns#31:nt#14:nc#559:\ :pa#15884:ba#8192:fa#1024:\ :pb#33440:\ :pc#242606:\ :pd#15884:bd#8192:fd#1024:\ :pe#55936:be#4096:fe#512:\ :pf#120466:bf#4096:ff#1024:\ :pg#192510:bg#4096:fg#1024: It is possible that our /etc/disktab and device driver are the result of a local hack since I do not have much idea of what my predecessor did when he installed the file systems. At any rate, the partitions do seem to be set up as in the first example ie. about 40Mb for partition g. The problem is that we do not use partition h and I don't know why. As far as I can gather, we have 55Mb of unused space on the disk. Is there a problem with using the whole R80, or should I just go ahead and % newfs /dev/rb0h rb80 One thing I noticed when looking at /etc/disktab was that the entry for the number of sectors in partition h (110143) is the only entry with an odd number in it in the whole table ie. with block size 4Kb and fragment size 1Kb, it will not divide up evenly. Any help on this matter would be greatly appreciated. If anyone is still awake at this point, I have one more question to ask. Where does the kernel learn what area of the disk to use as the secondary swap space? Is it hard-wired into the system from the entry in the configuration file ie. config vmunix root on XXXa swap on XXXb and XXXb or is it read from the appropriate entry in /etc/fstab ie. /dev/XXXb::sw:: or both? What happens if the entries do not agree with each other? Any replies should be sent by mail please. Thanks in advance, Scott Williamson. { ...!decvax!mcvax or ...!vax135!ukc!edcaad } !dice!scott