three questions

Lars Eighner eighner at io.com
Tue Nov 30 02:05:07 PST 2004


On Tue, 30 Nov 2004, Alexander Bubnov wrote:

> Hi!
> Could you answer my questions, please?
>
> 1) When I halt or reboot FreeBSD 5.3 I always receive following:
>   Syncing disks vnodes remaining... 4 3 3 1 1 0 done
>
> Is it OK? What does it mean?

Yes, it is okay, and in fact is really necessary.

Disk writes are very time consuming compared to writing to memory.
So many times the system does not actually write to disk, but writes
a memory image of the file.  It keeps track of where the latest version
of the file is in case, as often happens, it has something to do with
the file it has just written (as a memory image).  Eventually, of course,
the file has to be written to disk, and in particular, since files in
memory will be lost on powerdown or reboot, it is essential that the
files on disk be brought into *sync* with the memory images at such
times.

If you have ever had a power outage when you are working on the
computer, you may have noticed that you lost many "recent" changes
you have made to files - (and in addition, may have mess in the
filesystem requiring fsck).  This is because the working versions
of the files were not rendered to disk before the power went out.

So, in short, syncing disks is a good thing.  You can see man
sync for information on the sync utility (not the one used for
reboot) and references to other sync functions.  Although the
sync utility is does not set the whole system in complete order
as for reboot, it is a good idea to run it if you are going to
do something you suspect will crash the system.

> 2) When I download something from the Internet for a long time (around 9 
> hours) I always receive 3 strange letters (unfortunately, I deleted third 
> letter, sorry) from my OS (FreeBSD any versions), see below. What for? What 
> happen? Why do I receive them?

So far as I can tell these are the normal periodic maintence reports. Do you
usually power down the system when you are not using it?  If so, that is why
you do not get these reports on a regular basis. See /etc/crontab for when
these reports are scheduled to run (and man 5 crontab if you have difficulty
understanding crontab).  It is not a matter of your downloading anything
from the Internet, but that your system is up and running at the appointed
times. As I say, I suspect you power down your system except when you have
long downloads, and that is why you have come to associate long downloads
with receiving the reports.

> 3) I change resolution for consoles as vidcontrol -g 100x37 VESA_800x600 
> green. Can I change rate? How to do it?

I don't know what rate you mean.

-- 
Lars Eighner
eighner at io.com -finger for geek code-
http://www.io.com/~eighner/index.html
8800 N IH35 APT 1191 AUSTIN TX 78753-5266



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