Tres Melton posted <[EMAIL PROTECTED]>, excerpted below, on Sat, 25 Jun 2005 12:26:38 -0600:
> Yea, that was my understanding too but that's not right with portage <= > 2.0.51.19. Since I had never read otherwise I was in the habit of > invoking emerge thusly; "emerge -avDut --newuse pkg-name" and I was > getting screwed by the --update. Yes. I guess you posted your update mentioning that while I was in the middle of composing my 300-line reply. <g> It all makes sense, now. > From the LKML it would seem that the kexec function's first real (and > safe) use is to handle a kernel oops. The production kernel loads and > reserves a space for and loads a small data gathering kernel. In the > event of an oops the production kernel is in a questionable state so I/O > is immediately disabled (lest ye smoke thy data) and control is > transfered to the mini-kernel which can snapshot the running kernel, > memory, and swap and safely write that data out to storage. Then the > mini-kernel can cold boot the system resetting all the hardware and > everything to a known good state. Most of the kernel devs are against > any other use of kexec since I/O with a questionable current can put > your job and sanity at risk and bypassing the hardware reset brings in > all the issues of sw-susp leaving hardware in unknown (or not completely > known) states. Yeah, I'd read about that in LWN's kernel coverage. That's why I mentioned it. Nothing really new to me there, but I had been really brief on that point (uncharacteristically so <g>), and expanding it for anyone else following along is always helpful. Besides, reading the same thing put slightly differently is always good, as it reinforces the concepts and drives them home. >> One reboot alternative is to switch init levels, down to init 1 to stop >> nearly everything, then back to init 3 (or whatever) to restart most of >> the system. Note that on Gentoo, unlike on many distributions and *ix >> versions, init 1 does NOT mean single user mode that shuts down all the >> virtual terminals and what may be running from them. Thus, it's possible >> to keep a long-running process alive either in another virtual terminal >> (or in the background in your current terminal), or add them to a >> couple custom init levels, one with your usual other system stuff in it as >> well, one without most of it, then switch between those levels, so the >> long-running process doesn't stop. > > If I'm going to go that far down then I'm going to reboot. For me, once > I leave X there is no reason NOT to reboot. I know servers are totally > different beast though. Well, I too spend most of my time in X (KDE), but am quite comfortable in CLI as well, certainly to the point where I could never say once I leave X there's no reason NOT to reboot. Sometimes, I'll switch to a CLI VT and do my system maintenance tasks there, leaving X running in VT7. Other times, I'll shut down X/KDE and do my maintenance stuff, then start it up again. When I get the memory upgrade I'm looking at, not rebooting from an X shutdown will likely become even MORE common. I'll /hate/ rebooting, because with 4, possibly 8 gig of memory (I'm tempted to go to the full 16, but it's too hard to zero out the CC again when the balance gets that high), and apps normally only taking a quarter to a half a gig (it looks like I'll occasionally run a full gig of app memory) most stuff will stay in that 3-7 gigs of cache once read from disk the first time, so virtually everything will be loaded from cache, not disk. Rebooting will of course mean losing that cache, having to start over reading everything from slow disk once again. That'll SUCK, likely enough that I'll be trying to avoid it, even more than I do now, when it's no big deal. I'm not an uptime freak, usually rebooting every few days (uptime of almost 5 days, now, that one was a shutdown to depower the breaker box so I could trade out the a/c breaker, as it was getting weak and tripping, not a good thing here in Phoenix, with temps running ~45 C, 113 F, last week, a much more reasonable 40 C this week, still 30 C, 86 F, @ 4 AM), but I can imagine getting to the point where I'll complain about rebooting, since I rebooted "only" a week or two ago. That'll be particularly likely with the new SMP-suspend that's probably going to be in 2.6.13. Definitely looking forward to that! -- Duncan - List replies preferred. No HTML msgs. "Every nonfree program has a lord, a master -- and if you use the program, he is your master." Richard Stallman in http://www.linuxdevcenter.com/pub/a/linux/2004/12/22/rms_interview.html -- gentoo-amd64@gentoo.org mailing list
