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Home -> Community -> Mailing Lists -> Oracle-L -> RE: RMAN & SQL Backtrack
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I don't have any experience with SQL*Backtrack and I do have some experience
with RMAN. Here are my comments:
a) RMAN is reliable. Once you write the backup scripts, they are executed by
operations
and there no surprises. In order to rely on those scripts, one needs to test them, especially
the recovery part.
b) RMAN needs a 3rd party backup software to run. Things like OmniBackup,
Tivoli, Legato or
SyncSort can be rather expensive. RMAN doesn't write to tapes itself. RMAN delegates a
backup software contacted through the routines from libobk.so (or libobk.dll or libobk.sl) to
do its writing. To get the "libobk.so" from you backup software vendor of choice, you generally
have to write a check. That means that RMAN is NOT free. c) Before version 9, RMAN was arcane and hard to learn. Thanks to Robert Freeman, it is no
longer so. You can learn how to configure and use RMAN and you can find a decent book
to learn RMAN from. It's not very hard and it's fairly logical. One reading of the books suffices
for a good general understanding.
d) Quality of the software: RMAN leaves a lot to be desired. Its biggest
drawback is the fact that
it doesn't do any coordination with the underlying backup catalog. In other words, you can happily
declare backup obsolete in RMAN and Legato will not know anything about it and vice versa.
You can even delete backup in Legato and reuse the tape while RMAN knows nothing about it.
On the other hand, RMAN, in contrast to all other methods, does not put tablespaces into the
backup mode, thus generating floods of redo archives. RMAN doesn't backup data blocks that
have never been used ("behind the watermark blocks"), which is great if you have a fresh new
datafile which was added to the tablespace just in case something might
run out of space.
e) Personnel. Despite the certification process, it is not always easy to
find a trained personnel
which knows how to use it and how to recover the database. I consider the ability to recover
the database a basis for someone to call himself/herself a DBA. You would be surprised how
many people which claim that title do not know how to recover the database. Even smaller number
knows how to use RMAN.
f) I would suggest Jared Still, Cary Millsap, Rachel Carmichael, Jonathan
Lewis, Wolfgang Breitling,
Steve Adams, Gaja V., Arup Nanda, Kirti Deshpande and Anjo Kolk to start the Oracle List certification
process. I would trust that one more then the OCP. I apologize to anyone who I might have forgotten.
Mladen Gogala
Oracle DBA
Phone:(203) 459-6855
Email:mgogala_at_oxhp.com
-----Original Message-----
From: Smith, Ron L. [mailto:rlsmith_at_kmg.com]
Sent: Wednesday, July 16, 2003 10:59 AM
To: Multiple recipients of list ORACLE-L
Subject: RMAN & SQL Backtrack
We have been using SQL Backtrack for backup and recovery for about 6 years now. We are being pressured to start using RMAN because it is free. Makes sense but I am wondering about reliability, complexity, learning curve, etc...
Has anyone had experience with both products or anyone new to RMAN that can give me an idea of what to expect?
Thanks!
Ron
If you are not the intended recipient of this e-mail message, any use, distribution or copying of the message is prohibited. Please let me know immediately by return e-mail if you have received this message by mistake, then delete the e-mail message. Thank you.
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<DIV><FONT color=#0000ff face=Arial size=2><SPAN class=937141214-16072003>I
don't have any experience with SQL*Backtrack and I do have some
experience</SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN class=937141214-16072003>with
RMAN. Here are my comments:</SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN class=937141214-16072003>a)
RMAN is reliable. Once you write the backup scripts, they are executed by
operations</SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN
class=937141214-16072003> and there no surprises. In order to
rely on those scripts, one needs to test them, especially</SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN
class=937141214-16072003> the recovery
part.</SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN class=937141214-16072003>b)
RMAN needs a 3rd party backup software to run. Things like OmniBackup, Tivoli,
Legato or</SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN
class=937141214-16072003> SyncSort can be rather expensive.
RMAN doesn't write to tapes itself. RMAN delegates a</SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN
class=937141214-16072003> backup software contacted through
the routines from libobk.so (or libobk.dll or libobk.sl) to</SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN
class=937141214-16072003> do its writing. To get the
"libobk.so" from you backup software vendor of choice, you generally
</SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN
class=937141214-16072003> have to write a check. That means
that RMAN is NOT free.</SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN class=937141214-16072003>c)
Before version 9, RMAN was arcane and hard to learn. Thanks to Robert Freeman,
it is no </SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN
class=937141214-16072003> longer so. You can learn how to
configure and use RMAN and you can find a decent book</SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN
class=937141214-16072003> to learn RMAN from. It's not very
hard and it's fairly logical. One reading of the books suffices
</SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN
class=937141214-16072003> for a good general
understanding.</SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN class=937141214-16072003>d)
Quality of the software: RMAN leaves a lot to be desired. Its biggest drawback
is the fact that</SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN
class=937141214-16072003> it doesn't do any coordination with
the underlying backup catalog. In other words, you can
happily</SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN
class=937141214-16072003> declare backup obsolete in RMAN and
Legato will not know anything about it and vice versa.</SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN
class=937141214-16072003> You can even delete backup in Legato
and reuse the tape while RMAN knows nothing about it.</SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN
class=937141214-16072003> On the other hand, RMAN, in
contrast to all other methods, does not put tablespaces into
the</SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN
class=937141214-16072003> backup mode, thus generating
floods of redo archives. RMAN doesn't backup data blocks that
</SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN
class=937141214-16072003> have never been used ("behind
the watermark blocks"), which is great if you have a fresh
new</SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN
class=937141214-16072003> datafile which was added to
the tablespace just in case something might run out of
space.</SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN
class=937141214-16072003>e) Personnel. Despite the certification process,
it is not always easy to find a trained personnel</SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN
class=937141214-16072003> which knows how to use it and
how to recover the database. I consider the ability to
recover</SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN
class=937141214-16072003> the database a basis for
someone to call himself/herself a DBA. You would be surprised
how</SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN
class=937141214-16072003> many people which claim that
title do not know how to recover the database. Even smaller number
</SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN
class=937141214-16072003> knows how to use
RMAN.</SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN
class=937141214-16072003>f) I would suggest Jared Still, Cary
Millsap, Rachel Carmichael, Jonathan Lewis, Wolfgang Breitling,
</SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN
class=937141214-16072003> Steve Adams, Gaja V., Arup Nanda,
Kirti Deshpande and</SPAN></FONT><FONT color=#0000ff face=Arial
size=2><SPAN class=937141214-16072003> Anjo Kolk to start the Oracle List
certification</SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN
class=937141214-16072003> process. </SPAN></FONT><FONT
color=#0000ff face=Arial size=2><SPAN class=937141214-16072003>I would trust
that one</SPAN></FONT><FONT color=#0000ff face=Arial size=2><SPAN
class=937141214-16072003> more then the OCP. I apologize to anyone who I
might have forgotten.</SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN
class=937141214-16072003></SPAN></FONT> </DIV>
<DIV> </DIV>
<P><FONT face=Arial size=2>Mladen Gogala</FONT> <BR><FONT face=Arial
size=2>Oracle DBA</FONT> <BR><FONT face=Arial size=2>Phone:(203) 459-6855</FONT>
<BR><FONT face=Arial size=2>Email:mgogala_at_oxhp.com</FONT> </P>
<BLOCKQUOTE style="MARGIN-RIGHT: 0px">
<DIV align=left class=OutlookMessageHeader dir=ltr><FONT face=Tahoma
size=2>-----Original Message-----<BR><B>From:</B> Smith, Ron L.
[mailto:rlsmith_at_kmg.com]<BR><B>Sent:</B> Wednesday, July 16, 2003 10:59
AM<BR><B>To:</B> Multiple recipients of list ORACLE-L<BR><B>Subject:</B> RMAN
& SQL Backtrack<BR><BR></DIV></FONT>
<DIV><FONT face=Arial size=2><SPAN class=328505213-16072003>We have been using
SQL Backtrack for backup and recovery for about 6 years now. We are
being pressured to start using RMAN because it is free. Makes sense but
I am wondering about reliability, complexity, learning curve,
etc...</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=328505213-16072003></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN class=328505213-16072003>Has anyone had
experience with both products or anyone new to RMAN that can give me an idea
of what to expect?</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=328505213-16072003></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN
class=328505213-16072003>Thanks!</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=328505213-16072003></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN
class=328505213-16072003>Ron</SPAN></FONT></DIV>
<P><FONT face=Arial size=2>If you are not the intended recipient of this
e-mail message, any use, distribution or copying of the message is prohibited.
Received on Wed Jul 16 2003 - 09:40:54 CDT
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