The 'grubonce' command is a pretty little script if you are playing with various kernels. Basically, it lets you pick a GRUB menu boot option that it will boot from once and then go back to booting the old default. This is handy if you want to test out a new kernel and you want a safe way to check it out. This way, if the boot fails, your reboot will be back into the 'good' option. It is an undocumented perl script found in /usr/sbin, and looks like it implements this algorithm for you:
$ su -
Password: my root password
# grubonce
0: OpenSUSE 10.2 - Kernel-2.6.18.8-0.1-default
1: linux (/dev/hdb6)
2: Windows
3: Floppy
4: Kernel-2.6.18.8-0.1-xen
# grubonce 4
Using entry #4: Kernel-2.6.18.8-0.1-xen
# ^d
$
Pretty slick if you ask me!
When we call software “free,” we mean that it respects the users' essential freedoms: the freedom to run it, to study and change it, and to redistribute copies with or without changes. This is a matter of freedom, not price, so think of “free speech,”, not “free beer.”
Cool questionnaire to help you pick the right Linux distro. No idea how good it is, although openSuSE was one of my picks (others included PCLinuxOS, Kubuntu, and SimpleyMEPIS, all likable distros). See which ones you should try.
How to find out if you are using swap? These days, you should have plenty of memory, even with the piggish apps we all use. So you might want to find out how often you are using the swap space, to see if it is time to splurge on a RAM. Well, it is vmstat to the rescue:
$ vmstat 5
procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu----
r b swpd free buff cache si so bi bo in cs us sy id wa
1 2 204 4340 29984 140436 0 0 281 122 238 773 25 6 62 7
1 2 204 5636 26188 139620 0 0 1612 3793 1111 1953 5 5 1 89
0 2 204 8032 25420 133464 0 0 1516 30 1115 2342 6 6 0 87
1 1 204 7020 26068 130084 0 0 1444 89 1042 2289 10 7 0 83
0 1 204 13604 21472 129780 0 0 2158 65 937 1911 22 21 0 56
1 2 204 5884 22888 127960 0 0 1640 2 1180 2495 8 7 2 83
The main column you want to look at is the swap 'so' column. This tells you the amount of memory 'swapped out'. In my case, it is zero, so we're looking good, although I only have 1gb of RAM. I still think I'll grab another gigabyte. The '5' means to update the status every 5 seconds. And the first line shows the average of all the numbers since the machine was last rebooted, which is cool. As I've taken to shutting down all my machines every night, it isn't as interesting as it would have been a month ago, when the machine would run for weeks at a time.
Continuing my quest for Linux knowledge, I picked up three Linux magazines yesterday. It's a wonderful thing, really, to have something popular enough to actually have a pretty big selection of magazines to choose from that concentrate on it. For now, anyway, I'm enjoying my time in the sun!
I've also been casting about for a book. I've been using Safari for about six months now and enjoying it, but I want to have at least one real book in hand to read over. I liked the looks of Linux Administration Handbook, 2nd Edition and noticed it was 50% off at Bookpool.com, so I added Linux Bible 2007 Edition, which also looks real nice, with its discussion of 12 distros! And I see that openSUSE Linux Unleashed is on its way in June, so I pre-ordered that.
Although I'm happily married, with two kids, I still don't mind thinking myself "attractive" in some ways!-)
