Well, after a few have chipped in to the other side, I am going to have to
beg to differ.

Unix file systems, as all file systems, do tend to fragment, especially in
times of rapid growth of data on the file system, or in situations where
free space and free inodes on any given file system, become tight. Once file
systems have been heavily utilized, (75% full or higher), even if files have
since been deleted, there will be fragmentation.

Another situation where fragmentation may bite you is if you write large,
sequential files to disk, then delete them, then re-write similar large
files frequently, (i.e. spool files, etc...). Some post-relational database
applications can tend to do this. Any combination of these two situations
occuring can certainly contribute to fragmentation.

Granted, this does not seem to occur as often as it has in the past, or seem
to have as much impact. I have come across situations in the past where this
has brought platforms and applications running on them, to it's knees. If
the systems folks really would like to perform such a function, (AIX Backup,
Format Disk, Restore), it is not necessarily such a bad thing. I would go so
far as to recommend such operational functions be performed periodically,
especially if percent utilization of file systems can exceed 75%.

My two cents.

Regards,
Scott Richardson
Sr Systems Engineer / Consultant
Marlborough, MA 01752
****************************************
DPMonitor - http://www.deltek.us

----- Original Message ----- 
From: "Anthony W. Youngman" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Thursday, November 03, 2005 6:49 PM
Subject: Re: [U2] [UV] AIX Backup, Format Disk, Restore


> In message
> <[EMAIL PROTECTED]
> .com>, [EMAIL PROTECTED] writes
> >Does anyone out there still do this (if you ever have)?
> >
> >Take a backup of the file systems (in our case, AIX UNIX), format the
disks
> >clean, then restore the data back down to lay it back contiguous.
> >
> >Are there any (noticeable) I/O advantages to doing this for a UniVerse
> >database on today's servers?  Provided our files are properly sized, of
> >course.
> >
> >Our Systems guys are itching to do this.
> >
> Are they Microsoft-trained? :-)
>
> Unless you fill up the hard disk, Unix file systems don't fragment. The
> only real reason for this is if you're using LVM and your partition
> allocation has fragmented badly.
>
> In normal use, you should never need to defragment.
>
> Cheers,
> Wol
> -- 
> Anthony W. Youngman <[EMAIL PROTECTED]>
> 'Yings, yow graley yin! Suz ae rikt dheu,' said the blue man, taking the
> thimble. 'What *is* he?' said Magrat. 'They're gnomes,' said Nanny. The
man
> lowered the thimble. 'Pictsies!' Carpe Jugulum, Terry Pratchett 1998
> Visit the MaVerick web-site - <http://www.maverick-dbms.org> Open Source
Pick
> -------
> u2-users mailing list
> [email protected]
> To unsubscribe please visit http://listserver.u2ug.org/
-------
u2-users mailing list
[email protected]
To unsubscribe please visit http://listserver.u2ug.org/

Reply via email to