Frank Roberts - SOTL wrote:
> HELP!
> Netscape froze this morning in KDE.
> Since I could not do a <Ctrl><Alt><BkSpace> or <Ctrl><Atl><Del> with all
> keyboard keys froze I turned off the power.
> Big Mistake
You should always try "Ctrl-Alt-Bksp" to reset X-Windows. If that
fails, and you have a network, try telnet/ssh'ing in from another
system and killing X and/or kdm. After that try "Ctrl-Alt-Del" on
the system itself to reboot.
> System now comes up to /home or /var directory
> (it alternates between the two, one boot one the next boot the other)
> and says that there is an unexpected inconsistency; run fsck manually.
> HELP! Advice please before I mess something else up with my feeble
> attempts at repair.
All fsck is doing is "somethings not right and I don't want to do
anything without your approval." Usually fsck can automatically
check and figure out a few details, but sometimes there are some
temporary and other files that are accounted for.
Enter the root password, then run "fsck /dev/hdX" manually. If you
want to force it to answer "yes" to every question, run "fsck -y
/dev/hdX".
"WHY?" DISCUSSION ...
This happens on occassion. UNIX, in general, is _very_conservative_
in fixing things without approval. God knows Windows is not.
MS-DOS (incl. Windows 9x/ME) lets you bypass the whole procedure and
leave your system "unstable." Windows NT (incl. 2000/XP) uses a
very "aggressive" journaling filesystem that has toasted itself on
two of my servers in the past.
The reason why this even happens is because of buffering and
caching. Everytime you write data to disk, it doesn't go
immediately. If it did, your system would literally crawl in
performance. So when the system crashes or is shut-off improperly,
those buffers/caches might have not been "flush." So an fsck runs
and, if it has an issue, breaks down into the mode you are in.
I personally trust Linux's Ext2 more than most other filesystems.
It's structures are very reliable and its fsck is very
comprehensive. Not bad for version "0.5b", which is now 6 years
old! And it fragments less than just about other UNIX filesystem
(let alone any Windows one!).
Linux does have some journaling filesystems.
One is Ext3, which is based on Ext2, so I like it (although there
are some details and issue with various versions and kernels).
Another native Linux filesystem is ReiserFS, which is a very
advanced, extensible filesystem with fast, random small file
performance and breaks away from traditional UNIX FS design-isms
(and breaks some compatibility in some areas, most notabily
non-Linux NFS clients take issue and quota support is still not
available). Two "ports" from other OSes are SGI's XFS from Irix,
and IBM's JFS from OS/2 (as well as AIX, although it lacks some AIX
features). I have personally used XFS and prefer it, because it is
a very compatible, and has the most features to date (e.g., access
control lists, ACLs, including Samba 2.2 integration, as well as
official quota support).
For more info, see the following presentation (it's a little dated,
as Ext3 for kernel 2.4 is getting very "production quality," and
many NFS issues with ReiserFS have been at least partially solved):
http://smithconcepts.com/files/presentations/ITEC_JFS_2001Jun13.pdf
-- TheBS
-- Bryan "TheBS" Smith mailto:b.j.smith@ieee.org chat:thebs413 Engineer AbsoluteValue Systems, Inc. http://www.linux-wlan.org President SmithConcepts, Inc. http://www.SmithConcepts.com
This archive was generated by hypermail 2.1.3 : Fri Aug 01 2014 - 19:26:11 EDT