IDS Forum

Re: Ontape backup

Posted By: Art Kagel
Date: Monday, 22 March 2010, at 12:58 p.m.

In Response To: Ontape backup (DEEPAK JOSHI)

Backup times will depend on the IO throughput of the subsystem to which it
is being written and of that of the chunks that are being backed up. Also
if the chunks are on some of the same physical structures that the archive
is being written to, there will be contention for the disk heads. Finally
the configuration of the EMC RAID group that you are writing the archive
file to will affect the back up throughput (ie RAID5 is 40% slower than
RAID10 for sustained sequential writes which is what the archive is doing).

Differences in archive times day to day can be due to activity on the server
- more updates/inserts/deletes will require that more pre-image data from
the physical log be copied out to the archive after each dbspace's back up
is completed to maintain consistency of the archive. Another cause can be
contention with other applications for IO bandwidth to the EMC array or even
between the machine that is hosting the IDS instance and other machines on
the network that may be sharing the same EMC array.

Art

Art S. Kagel
Advanced DataTools (www.advancedatatools.com)
IIUG Board of Directors (art@iiug.org)

See you at the 2010 IIUG Informix Conference
April 25-28, 2010
Overland Park (Kansas City), KS
www.iiug.org/conf

Disclaimer: Please keep in mind that my own opinions are my own opinions and
do not reflect on my employer, Advanced DataTools, the IIUG, nor any other
organization with which I am associated either explicitly, implicitly, or by
inference. Neither do those opinions reflect those of other individuals
affiliated with any entity with which I am affiliated nor those of the
entities themselves.

On Mon, Mar 22, 2010 at 12:50 PM, DEEPAK JOSHI <djoshih@hotmail.com> wrote:

> Hi All,
>
> We are running informix 7.13 on HP-UNIX 10.01. We are taking a weekly level
> 0
> backup of informix and writing backup to EMC clarrion. We noticed every
> time
> backup will complete at different time, usually it took 14 to 15 hrs to
> complete. We have a database of size 36 GB.
>
> Is that the normal behavior of ontape to backup 36Gb of data in 14 to 15hrs
> or
> we can do something to complete it faster? Secondly, can anybody help me to
> troubleshoot why the backup time varies every time.
>
> Regards
> Deepak
>
>
>
> *******************************************************************************
> Forum Note: Use "Reply" to post a response in the discussion forum.
>
>

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Messages In This Thread

• Ontape backup
  DEEPAK JOSHI -- Monday, 22 March 2010, at 12:49 p.m.
  • Re: Ontape backup
    Art Kagel -- Monday, 22 March 2010, at 12:58 p.m.
  • Re: Ontape backup
    Eric Rowell -- Monday, 22 March 2010, at 1:04 p.m.
  • Re: Ontape backup
    Art Kagel -- Monday, 22 March 2010, at 1:08 p.m.
  • Re: Ontape backup
    Marco Greco -- Monday, 22 March 2010, at 2:15 p.m.

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