Does Linux offer a Reliable Filesystem?

Does Linux offer a Reliable Filesystem?

Post by Glenn Rys » Thu, 21 Apr 1994 13:45:22



Linux users -  I'm just about to install my first Linux system
as soon as the CD arrives.  In preparation, I've been reading
all the documentation I can find.  However, I still have a question
regarding the filesystems offered by Linux.  

Does Linux offer a reliable filesystem such as Veritas on SVR4.2?
Since I'm going to be using Linux on a laptop I would be very
disappointed to see my files disappear when the battery dies.

Thanks,

Glenn Rysko

 
 
 

Does Linux offer a Reliable Filesystem?

Post by Ron Smi » Tue, 26 Apr 1994 07:02:59


: Linux users -  I'm just about to install my first Linux system
: as soon as the CD arrives.  In preparation, I've been reading
: all the documentation I can find.  However, I still have a question
: regarding the filesystems offered by Linux.  

: Does Linux offer a reliable filesystem such as Veritas on SVR4.2?
: Since I'm going to be using Linux on a laptop I would be very
: disappointed to see my files disappear when the battery dies.

: Thanks,

: Glenn Rysko

--

The Veritas filesystem (vxfs) is not in the public domain and I haven't
seen anything in the groups about it. But ... I've been running Linux on a
laptop for more then 8 months, and even when the batteries die, I don't lose files.
This is because of the update program, that syncs the buffers every 30 secs.
furthermore, the ext2fs filesystem is extremly good.

                Ron Smits


/*-( My opinions are my opinions, My boss's opinions are his opinions )-*/
/*-(                They might not be the same                        )-*/

 
 
 

Does Linux offer a Reliable Filesystem?

Post by Robert Sande » Wed, 27 Apr 1994 03:14:50




>: The Veritas filesystem (vxfs) is not in the public domain and I haven't
>: seen anything in the groups about it. But ... I've been running Linux on a
>: laptop for more then 8 months, and even when the batteries die, I don't lose files.
>: This is because of the update program, that syncs the buffers every 30 secs.
>: furthermore, the ext2fs filesystem is extremly good.
>Update has nothing to do with vxfs or its reliability, it runs on any other

Yesssss...he didn't say it had anything to do with Veritas.  Usenet myopia
reigns supreme.

Quote:>filesystem.  And what happens if you write 5 sec. after your last update and
>then 2 sec. later lose power?  Your write has not been actually written to
>the disk and you _do_ lose your data, right?  This update/syncing thing is
>exactly what makes unix filesystems so vulnerable to crashes.

People don't seem to understand the advantage of log-structured filesystems.
Look, there is no way to ensure that every write gets to disk before power
fails.  WHat you can do is to make sure that no matter when the power fails,
the filesystem is in a consistent state, or can be gotten to one rather easily.
Log-structured filesystems do that by discarding all the activity since the
last provable "consistent" state, so you're as likely to lose recently-written
data on Veritas as on ext2fs; the difference is that with ext2fs, FFS, and
other more traditional filesystems, there's a chance of losing old data
as well.

No UNIX filesystem bypasses the writeback cache; the performance hit would
be tragic.

--

`*MV' hi,ocie! |-/ad! /   \ss!!  | ooga ooga!!    |    II (cool)!         `VW*'

 
 
 

Does Linux offer a Reliable Filesystem?

Post by Davor Cubran » Wed, 27 Apr 1994 00:37:40



: : Does Linux offer a reliable filesystem such as Veritas on SVR4.2?
: : Since I'm going to be using Linux on a laptop I would be very
: : disappointed to see my files disappear when the battery dies.

: The Veritas filesystem (vxfs) is not in the public domain and I haven't
: seen anything in the groups about it. But ... I've been running Linux on a
: laptop for more then 8 months, and even when the batteries die, I don't lose files.
: This is because of the update program, that syncs the buffers every 30 secs.
: furthermore, the ext2fs filesystem is extremly good.

Update has nothing to do with vxfs or its reliability, it runs on any other
filesystem.  And what happens if you write 5 sec. after your last update and
then 2 sec. later lose power?  Your write has not been actually written to
the disk and you _do_ lose your data, right?  This update/syncing thing is
exactly what makes unix filesystems so vulnerable to crashes.

--
Davor Cubranic

 
 
 

Does Linux offer a Reliable Filesystem?

Post by John R. Campbe » Sat, 30 Apr 1994 01:24:36



>Update has nothing to do with vxfs or its reliability, it runs on any other
>filesystem.  And what happens if you write 5 sec. after your last update and
>then 2 sec. later lose power?  Your write has not been actually written to
>the disk and you _do_ lose your data, right?  This update/syncing thing is
>exactly what makes unix filesystems so vulnerable to crashes.

I have not looked (myself) yet-  does Linux support O_WSYNC in fcntl()???

Otherwise, is fsync() implemented?

We already _know_ that sync() is implemented.  If you need reliable
writes, use O_WSYNC first (if present), fsync() is O_WSYNC ain't present,
and sync() when you're _really_ desperate.

Just remember, forced (synchronous) writes will _slow_ your application
by quite a bit-  but that's the cost of doing business...

--


        When cryptography is outlawed, bayl bhgynjf jvyy unir cevinpl
  GUNs don't kill people, but GNU's not UNIX.  (National Non-Sequitur Society)

 
 
 

1. What can Linux offer that Win95 or OS/2 Wrap doesn't offer

I have heard a lot about Linux but I wonder what can Linux offer someone
who is currently using Win95 or OS/2 Wrap. Do people use if for
application development primarily since from what I know the number of
software for Linux is smaller than Win95.

I am considering installing Linux onto my computer since my school uses
UNIX and I wish to do my work (mostly compilation of programs) at home.
Would you recommend me to install Linux onto my computer?

2. Using JNI on Linux

3. Need reliable/stable BACKUP tool/method for 24hr filesystems

4. hp 680c only prints ascii now?

5. Reliable non-buffering removable filesystem

6. CDE under Solaris 2.4

7. Is pkgchk reliable also is pkgadd reliable ?? 2.3

8. Menu Utility

9. Need good dos emulator (one that is reliable)

10. Accessing Linux filesystems from DOS

11. How to access Linux filesystem while running dos?

12. Linux filesystem like DOS RAM-disk?

13. HELP: Connectivity between DOS/DOS and DOS/Linux