IDS Forum

Re: Archive ABORTED

Posted By:
Date:

Hi,

it can well be a problem of tape space shortage.

But first of all I would check the error message that was
produced by the backup front end :
- If you're using "ontape", then you have to check it's
output on stdout/stderr to get more info.
- if you're using ON-Bar, then check the ON-Bar Activity
Log (configured in $ONCONFIG file by BAR_ACT_LOG).

Tape capacity is something that can be discussed for
hours without end ...
Usually a tape device does some compression and often
the tape vendor refers on the label of the tape to size of
compressed data.
Unfortunately all these are (best) guesses. The compression
rate (of any data compression without actual data loss)
depends on the data itself. If that data is compressed already,
then applying another "round of compression" on it may actually
INCREASE the size of the data. Common utilities like "gzip"
nowadays recognize this and leave such data as is, not
compressing it a second time ...
But I don't know, what the hardware compression algorithm of
your tape device is doing in such a case.

In most cases where there are such lengthy discussions with
customers, it turns out that they have some kind of BLOBs in
their database and these BLOBs contain already-compressed
data (e.g. GIF or JPEG files). During backup to a tape with
(hardware) compression, it can easily happen that these BLOB
data actually become bigger on tape (rather than smaller) with
the net-effect that the tape capacity seems to be smaller than
what the vendor claims it would be. This is due to the fact that
the average compression rate over all the data cannot be
achieved ...

Apart from that, IDS backup only archives data pages that are
in use. If a table has allocated a large extent, that does not mean
that all the pages in that extent will be archived. Only those pages
of the extent that are actually in use (i.e. data has been written to
them) will be archived. Pages that are (still) free (empty) are not
archived.
Try "oncheck -pT ..." to get a more acurate picture of the pages
actually used in your system ...

Regards,
Martin
--
Martin Fuerderer
IBM Informix Development Munich
Data Management Solutions





"Serdar Can" <scan@bellona.com.tr>
Sent by: forum.subscriber@iiug.org
29.04.2003 08:44


To: ids@iiug.org
cc:
Subject: Archive ABORTED [1020]




hi all,
when i check the online.log ,i have seen the following message:
21:05:30 Archive on rootdbs, plogdbs, llogdbs, datadbs, idxdbs, =
data3dbs ABORTED.

also both tfgld418 and tfgld410 tables have allocated new extent ,each =
1,900,000 KB in size .
now in our database the total used page in size is 79.647 GB.(it is the =
the sum of rootdbs, plogdbs, llogdbs, datadbs, idxdbs, data3dbs) and the =
capacity of our Archive tape is 80 GB.

we are taking Level 0 archive every night,and before these tables havent =
got new extend our Level 0 archives were succesful.
Do you think this problem is related with free tape shortage?

Messages In This Thread

• Archive ABORTED
  Serdar Can -- Tuesday, 29 April 2003, at 2:44 a.m.
  • Re: Archive ABORTED
    Martin Fuerderer -- Tuesday, 29 April 2003, at 3:59 a.m.
  • RE: Archive ABORTED
    Simmons, Keith -- Tuesday, 29 April 2003, at 4:15 a.m.
  • Re: Archive ABORTED
    Serdar Can -- Tuesday, 29 April 2003, at 11:55 a.m.
    • Re: Archive ABORTED
      Clifton M. Bean -- Tuesday, 29 April 2003, at 1:59 p.m.

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