Hello Everybody,
I have received lot of responses to my question. I would like to
thank you all for responding to my query. Here is the summary of the
responses.
Mohan Mahajan
Email : mmahajan_at_anand.nddb.ernet.in
**************************************************************
--- On Thu, 27 Jun 1996 10:33:45 +0530 Mohan Mahajan
<MMAHAJAN_at_anand.nddb.ernet.in> wrote:
>Hello OSF Manangers,
>
>I would like to know the advantages/disadvantages of Advfs (advanced
>file system) of Digital Unix over ufs (unix file system). I am using
>file system type as ufs for all the partition. I checked with the
>digital support engineer about advfs, I didn't get satisfactory
>answer. I found that most of people are using advfs and thinking of
>using it for new hard disks. I appriciate your comments, suggestion.
>
>Thanks in advance.
>
>Mohan Mahajan
>NDDB, Anand
>Email : mmahajan_at_anand.nddb.ernet.in
>
-----------------End of Original Message-----------------
Mohan,
I'm using ADVfs for all filesystems except one. I have
one which doesn't use it as a backup file system which can be
used for testing. I have found the following advantages and
disadvanges with ADVfs:
Advantages: Cacheing with DEC's Prestoserve board (read+write
cache) works well. (it might work well with ufs, too)
The filesystem doesn't seem to corrupt too easily. I did have
some trouble with firmware revisions early on, but since that
was resolved it's worked pretty well under moderate load.
Digital engineering is investing time in improving this filesystem.
Disadvantages: All directory files are at least 8K long
There aren't too many tools for fixing problems. I've had to
recreate corrupt filesystems which means a full restore. DEC
has a lot of room for improvement here. I also have have their
optional ADVfs tools product which has graphical tools which is
nice, but their still is no good recovery/repair tool. That
concerns me.
I'm sure their are other technical reasons to use or not to use
ADVfs, these are the practical things I've seen.
Ron
-------------------------------------
Name: Ron Barrett
E-mail: ron.barrett_at_cubic.com
Date: 6/27/96
Time: 7:44:12 AM
-------------------------------------
Hi Mohan,
We currently use advfs on ALL disks and its works well. We went
to advfs so as to avoid the long fschk after a system failure. As
advfs is a journalled file system it starts quicker. One point is
that to convert from ufs to advfs requires you to backup and
restore the filesystem so it is then advfs.
Regards,
Craig Makin
System Administrator
Ferntree Computer Corp.
Perth, Australia
--------------------------------------------------------------------
Hi Mohan,
We running advfs on all our Alpha's, 2x 2100, 1x 1000, 1x 3000
We running d_unix 3.2B, all works fine, no perfect....
The only think we had:
The 2100 crashed on Advfs , Digital Netherlands send us
a view patches.
Regards, Gert...
-------------------------------------------------------------------
Gert Maaskant. _______ _ ___
| _|_|_ | Gert.Maaskant_at_nedlloyd.nl
| _(_____| | Nedlloyd Computer Services
| _(_____) | P.O. Box 2454
| |_____) | 3000 CL Rotterdam (The Netherlands)
|__ |_| ______| +31 10 - 400 7400 Fax: +31 10 - 4006345
-------------------------------------------------------------------
ADVFS Advantages:
1) No fsck required at boot time, so booting after a power
outage is much faster, especially with larger (multi-gigabyte)
drives.
2) Very easy storage management. You can move storage around
between file systems without disrupting active processes.
3) You can clone a fileset, and backup the clone. This gives
you a consistent backup, even with concurrent activity on the
original fileset.
4) You can stripe individual files across multiple volumes,
giving major performance improvements in some types of
applications. Note: This is different from RAID 0, which ADVFS
doesn't do, though you can certainly implement ADVFS on top of a
RAID set.
5) You can defragment a file system or an individual file
concurrently with normal use.
ADVFS Disadvantages:
1) Items 2-4 above, and perhaps 5, require the extra cost ADVFS
Utilities product.
2) It doesn't do well with applications like news spools where
you need a huge number of small files, though I understand this
has been improved in recent versions.
3) Stability and robustness problems:
There have been several bugs with Advfs, some of which cause
system crashes. You MUST keep up with the latest patches.
Error messages, diagnostics and repair utilities aren't documented
well.
Should be more robust in the face of disk hardware failures.
I've seen data corruption and system crashes as a result of
failing disk drives with no advanced warnings in the error logs.
This may be the fault of Digital Unix (or Unix in general)
rather than ADVFS. ADVFS isn't magic, after all.
For us here at SPU, the advantages far outweigh the disadvantages.
--
-- Phil Rand <prand_at_spu.edu> aka <postmaster_at_spu.edu>
-- http://paul.spu.edu/~prand/ (206) 281-2428
-- Computer & Information Systems
-- Seattle Pacific University
-- 3307 3rd Ave W, Seattle, WA 98119
------------------------------------------------------------------
- It gives you a lot of flexibility. You can add more space to a
fileset without reformatting. You can also do it through LSM,
though.
- It allows you to do online backups through the use of clone
filesets.
- It is FASTER (I mean much much faster). Of course, if you do
long transfers you won't notice any difference, but it speeds
file creation, opening, renaming, etc, a lot. I really did notice
the speed increase when I moved to AdvFS.
Greetings,
Pedro.
-------------------------------------------------------------------
Pedro Jose Lobo Perea Tel: +34 1 336 79 29
Centro de Calculo Fax: +34 1 331 92 29
EUIT Telecomunicacion - UPM e-mail: pjlobo_at_euitt.upm.es
Hi,
yes, I prefer usage of AdvFs !
Advantagees:
- Very short and actually better fsck !
- Online defagmentation possible.
- You can combine two or more "hard" devices to one singele
filesystem.
... maybe some more, but those are most important to me
Disadvantages:
- You need a license for AdvFs-Utilities ( maybe included in some
NAS license ...)
- I think one of the main pitfalls will occure if you make a full new
installation. When the root file system is replaced, the descriptive
directory "fdmns" in "/etc" is also deleted.
for use with DU3.2C I used a smal script, I will append to the
message.
Karl-Heinz Dewenter
AEG Atlas Schutz und Leittechnik GmbH
Bremen, Deutschland
--------
#! /bin/zsh
# sorry, I used zsh, but it should work with /bin/sh as well
# as printer I used "ps", you perhaps have to change this
#
HOST=`hostname | cut -d"." -f1`
#echo $HOST
SV_FILE=/tmp/advfs-on_${HOST}.sh
HLP_FILE=/tmp/hlp_${HOST}
#
if [ ! -d /etc/fdmns ]
then
echo "No /etc/fdmns directory"
echo " No Advanced Filesystems found!"
fi
#
lpr -Pps /etc/fstab
ls -lR /etc/fdmns | lpr -Pps
#
echo "#! /bin/sh" > $SV_FILE
echo "mkdir /etc/fdmns" >> $SV_FILE
for i in `ls /etc/fdmns`
do
echo "mkdir /etc/fdmns/$i" >> $SV_FILE
done
find /etc/fdmns -type l -ls | cut -c69- | sed -e "s/ //g" > $HLP_FILE
#for lin in `find /etc/fdmns -type l -ls | cut -c69-`
for lin in `cat $HLP_FILE`
do
# echo "=$lin="
x=`echo $lin | cut -f1 -d'-'`
y=`echo $lin | cut -f2 -d'>'`
echo "ln -s $y $x" >> $SV_FILE
done
---------------------------------------------------------------
Two things to beware of: Advfs does not work very well with LSM,
though the manuals will try to tell you otherwise, and it really
doesn't work at all for a Usenet news filesystem, though the
manuals will try to tell you otherwise.
We've been using Advfs since OSF/1 2.0 and have had more
problems with it than you can shake a stick at. Most of these
problems have been fixed in recent releases, but several
(including LSM and news interaction) have not.
jonathan
--
+++ Jonathan Rozes, Unix Systems Administrator, Tufts University
++ jrozes_at_tcs.tufts.edu, http://rozes.tcs.tufts.edu/
+ Ultimately, thinking is a very inefficient method of processing
data.... [Surfing the Himalayas, 0-312-14147-5]
Received on Fri Jun 28 1996 - 06:55:54 NZST