tkevans@fallst.UUCP (Tim Evans) (11/09/89)
I've recently inherited system-administration responsibility for 4 VAX 11/750's running 4.2 BSD and have been rummaging around on them. I've discovered that, although /etc/rc starts up 'swapon -a' there is no swap partition defined in /etc/fstab. Our vendor is unable to locate any records on why this might have been set up in this fashion. Their response was that "BSD does paging so maybe you don't need swapping" (!!!). /etc/disktab's entry for the Eagle disk(s) on the 4 machines appears to show a 'b' partition having been defined. Question is: lacking any records on why this system was set up in this fashion, can I safely throw a line into /etc/fstab defining partition 'b' as swap? Thanks. -- UUCP: uunet!anagld!aplcen!fallst!tkevans INTERNET: tkevans@wb3ffv.ampr.org OTHER: attmail!fallst!tkevans Tim Evans 2201 Brookhaven Ct, Fallston, MD 21047 (301) 965-3286
danl@midget.towson.edu (11/10/89)
Tim Evans <tkevans@fallst.uucp> writes: >11/750's running 4.2 BSD and have been rummaging around on them. I've >discovered that, although /etc/rc starts up 'swapon -a' there is no >swap partition defined in /etc/fstab. I run Ultrix on VAXen, which is a descendent of BSD, so I'm assuming this all works the same. "swapon -a" adds secondary or supplemental swap space (namely other disk partitions marked :sw: in /etc/fstab and configured into the kernel) to the primary swap which is also defined in the kernel config file. Try looking in /usr/sys/conf/machine_name for something like: config vmunix root on ra0a swap on ra0b dumps on ra0b The above specifies ra0b as my primary (and only) swap space, and therefore needs no entry in /etc/fstab. "swapon -a" is in your /etc/rc in case you want to add other partitions as swap. To do this you need to add the parttion to the config file, reconfig the kernel, add the partition to /etc/fstab, and reboot. The line: config vmunix root on ra0a swap on ra0b swap on ra1b dumps on ra0b specifies ra0b as my primary swap and ra1b as an optional secondary swap to be added by "swapon -a" if it is in /etc/fstab. >/etc/disktab's entry for the Eagle disk(s) on the 4 machines appears to >show a 'b' partition having been defined. The "b" partition is usually used for swap, so if your system is running and all you have is the one drive, it is probably already being used. Try "pstat -s" to see it's size, and check the config file again for its location. You shouldn't take /etc/disktab as gospel though, because it's values are only default suggestions, and can be over-ridden by chpt. Try "chpt -q" to see how the disk is really layed out. I have two Eagle's on one system and interleave the swap between them. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Dan Gosner Internet: danl@midget.towson.edu Operations Manager DGosner@TOE.TOWSON.EDU Towson State University Bitnet: DGosner@TOWSONVX Academic Computing Towson, Maryland 21204 %% VMS pays the bills, but Unix is where my real work gets done. %%