Leaving Mac On -- Advantages / Disadvantages
in [Mac Systems]
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From: Barry Margolin on 16 Feb 2010 12:52 In article <_zAen.66910$PH1.50953(a)edtnps82>, me(a)home.spamsucks.ca (Kir�ly) wrote: > TaliesinSoft <taliesinsoft(a)me.com> wrote: > > I somehow feel easier having the nightly maintenance routines run when > > I am not doing other things. > > Why? You you expect that something might get corrupted if the two tasks > run simultaneously? Or that you will notice some slowness? If I'm logged into my iMac when the maintenance runs (especially the weekly script early Monday morning), I can definitely tell the difference. -- Barry Margolin, barmar(a)alum.mit.edu Arlington, MA *** PLEASE post questions in newsgroups, not directly to me *** *** PLEASE don't copy me on replies, I'll read them in the group ***
From: Richard Maine on 16 Feb 2010 13:57 Barry Margolin <barmar(a)alum.mit.edu> wrote: > In article <_zAen.66910$PH1.50953(a)edtnps82>, > me(a)home.spamsucks.ca (Kir�ly) wrote: > > > TaliesinSoft <taliesinsoft(a)me.com> wrote: > > > I somehow feel easier having the nightly maintenance routines run when > > > I am not doing other things. > > > > Why? You you expect that something might get corrupted if the two tasks > > run simultaneously? Or that you will notice some slowness? > > If I'm logged into my iMac when the maintenance runs (especially the > weekly script early Monday morning), I can definitely tell the > difference. And there are some kinds of apps where it is tricky to get a valid backup while the app is running unless you go to a lot of extra work. Database apps are notorious for that, but there are others as well. It is actually a rather messy subject, but for a simple example, consider an app that might involve two related files that need to be in sync - perhaps a data file and a separate file that indexes the data file. If the files are being actively modified during the backup run, you can get easily get an index file that doesn't match the data file. Even milliseconds of difference between when you backup the two files can matter. And then there are the issues of a file that is being changed while you are backing it up so that by the time your backup reads the last part of the file, that part no longer agrees with what it read a little earlier from the first part. Yes, there are solutions to those kinds of problems. But sometimes the solutions can get quite messy. Major database products typically come with custom backup modules tailored to the specific product. And the fact that the problems can be addressed doesn't mean that the particular apps that you might be using have addressed them... or that the solutions don't have holes. For consumer products like most Macs, odds are that this kind of issue isn't very high on the priority list of most products, when it is considered at all. It is fairly common to ignore some kinds of backup problems on the theory that even if you occasionally get a bad backup, you can always used the one from the day before and just loose one day's of data. Unfortunately, that ignores the possibility of the problems being consistent, as can happen if, say, you scheduled backup always runs during the same time as some scheduled database maintenance - or if there is an app that is always running. Professional datacenter design spends a *LOT* of time considering issues like this. Things still sometimes get mucked up, as the issues are far from trivial. At the consumer level, the degree of work put into it is lower. Admitedly, the risks are also generally lower. -- Richard Maine | Good judgment comes from experience; email: last name at domain . net | experience comes from bad judgment. domain: summertriangle | -- Mark Twain
From: AES on 16 Feb 2010 14:37 In article <160220101143539068%star(a)sky.net>, Davoud <star(a)sky.net> wrote: > TaliesinSoft wrote: > > > Except when I have my MacBook Pro away from home I leave it > > continuously on, having the display go to sleep after five minutes of > > inactivity. Leaving it on during the night is so that the nightly > > maintenance routines and my scheduled backups will run. Anachron is supposed to allow you to turn it off, but have maintenance routines still run when it's turned back on. Anyone have more detailed info about Anachron? I installed it; nothing bad seems to have happened; but I also have no idea if it's really doing anything.
From: Tom Stiller on 16 Feb 2010 14:54 In article <siegman-0C9668.11371716022010(a)news.stanford.edu>, AES <siegman(a)stanford.edu> wrote: > In article <160220101143539068%star(a)sky.net>, Davoud <star(a)sky.net> > wrote: > > > TaliesinSoft wrote: > > > > > Except when I have my MacBook Pro away from home I leave it > > > continuously on, having the display go to sleep after five minutes of > > > inactivity. Leaving it on during the night is so that the nightly > > > maintenance routines and my scheduled backups will run. > > Anachron is supposed to allow you to turn it off, but have maintenance > routines still run when it's turned back on. > > Anyone have more detailed info about Anachron? I installed it; nothing > bad seems to have happened; but I also have no idea if it's really doing > anything. If you run Leopard or Snow Leopard, there is no need for Anachron. The launchd process takes care of ensuring that the maintenance processes run in a timely fashion. As far as I know, the only thing that needs the machine to be awake between midnight and 1:00 AM is the rollover of the system log file. This can be changed by modifying the appropriate entry in /etc/newsyslog.conf. -- Tom Stiller PGP fingerprint = 5108 DDB2 9761 EDE5 E7E3 7BDA 71ED 6496 99C0 C7CF
From: Jason Bourne on 16 Feb 2010 15:22
Davoud wrote: > TaliesinSoft wrote: > >> Except when I have my MacBook Pro away from home I leave it >> continuously on, having the display go to sleep after five minutes of >> inactivity. Leaving it on during the night is so that the nightly >> maintenance routines and my scheduled backups will run. What I'd be >> interested in knowing is what disadvantages are there to leaving my >> computer on in this manner. > > The disadvantage is that for each computer left on overnight that's a > little more energy wasted, a little more CO2 pumped into the > atmosphere... > > Not trying to send anyone on a guilt trip here; if one has a reason for > leaving a computer on 24/7, one should follow one's own preferences. At > the same time, in order to make an informed decision one should be > aware that if one is "on the grid" the consequences reach beyond one's > own home. > > Davoud > You must be one of those silly people who believes that what we do has any material effect on global temperature? "Global warming" is discredited junk science espoused primarily by politically correct knee-jerk liberals and one-world socialists... |