Re: [EXTERNAL] Re: rman backup slow even after patching it

From: David Barbour <david.barbour1_at_gmail.com>
Date: Mon, 22 Aug 2022 10:20:05 -0500
Message-ID: <CAFH+ife1f4tRwKLe2pc6TZksXfFigo4pZhXY0rwzaoWmXdQiVg_at_mail.gmail.com>



What is your backup target? Source media? Third-party backup application? We had a problem with backing up to Oracle Cloud after moving to 19.15 and the solution turned out to be re-installing the Oracle Database Cloud Backup Module . Seems there is a mismatch with the older oci interface. I wouldn't bet against a similar issue with the libraries in 19.14.

On Tue, Aug 16, 2022 at 10:38 AM Mladen Gogala <gogala.mladen_at_gmail.com> wrote:

> On 8/16/22 09:44, Beckstrom, Jeffrey wrote:
>
>
>
> In a rare factual error my friend Mladen missed that the list is ascending.
>
>
>
> Still probably a network issue. Smirk. Unless that is backup & recovery
> read time (The key thing that **might** tell you a **lot** would be
> separation of I/O into I and O). I cannot remember their detailed
> description of this event and I’m too lazy to too it up. But I did
> re-arrange the output for that one line into “What” and useful “How much”
> columns.
>
>
>
> Notice that the “also ran” second place was only about a minute of total
> wait. So this one bundled line for I and O is pretty much everything. So 41
> milliseconds per I/O and I have no idea what a raw system level I/O between
> your source system and backup system is, or what size RMAN’s I/O unit is
> (min, max, average) as configured. If you have some idea of the total bytes
> written, you could do a system to system level I/O of that size (maybe a
> bundle of 100 or 1000 repeats, so any possible begin and end process time
> error is minimized) and get a clue whether I/O time between systems is the
> problem, rather than something more complex inside Oracle.
>
>
>
> Of course, Mark is right. I am using similar kind of query with "DESC"
> option for the ordering so I assumed that Jeff does the same. Apparently,
> my assupmtion was wrong. Not only that, rman network communication doesn't
> use SQL*Net, so the "SQL Net data to client" message is unlikely to be
> caused by rman. It *might*, however, be indicative of a network problem.
> My advice would be to also check disk I/O and network throughput using the
> Linux tools like atop, iotop and iptraf-ng. Even strace can be useful in
> this situation. Also useful are "perf" tools, like "perf top" and system
> wide profilers like "oprofile".
>
> You may need to open a case with Oracle or your backup vendor.
>
> Regards
>
> --
> Mladen Gogala
> Database Consultant
> Tel: (347) 321-1217https://dbwhisperer.wordpress.com
>
>

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Received on Mon Aug 22 2022 - 17:20:05 CEST

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