Oracle-L: RE: Message ARC0: Failed to archive log

From: DENNIS WILLIAMS <DWILLIAMS_at_LIFETOUCH.COM>
Date: Tue, 25 Jun 2002 09:54:15 -0800
Message-ID: <F001.004871BA.20020625095415@fatcity.com>

Barbara - I asked exactly the same question last fall, and here is the reply that Ron was kind enough to supply:

Organization: Fat City Network Services, San Diego, California Date: Wed, 14 Nov 2001 16:15:47 -0800

The alert is just telling you that there was a delay archiving your redo log. This does not mean that you have lost any data, or archive logs, but it can become a bottleneck in your database if transactions have to wait for archiving on a regular basis. If this was during a normal activity/load period, then you may need to look into the efficiency of your redo and archive file systems.

e.g. Your redo logs are on separate file systems so when the disk is done receiving write requests, it is free to perform reads necessary for archiving.

Your archive file system is separate from your redo file systems so it is always read to process the writes requests necessary to copy redo logs.

Your redo file systems and archive file systems are on dedicated spindles or striped across several spindles that are not used for other concurrent activity, e.g. not shared with data files.

You should also look into the frequency of log switches, if this is too frequent, then it is easy to need a redo log before adequate time has expired for the archiving to occur. (General rule, log switches every 15 minutes are satisfactory for most OLTP systems.)

HTH
-Ron-

-----Original Message-----

Sent: Tuesday, June 25, 2002 12:24 PM
To: Multiple recipients of list ORACLE-L

Sun Solaris 5.8
Oracle Release 8.1.7.2.0

List:
We have a small but critical database that gets bursts of activity. If left to their own devices, the 50meg redo logs sometimes switch a few per hour; sometimes do not switch for several hours.

We're manually populating a standby database, so we're forcing a switch (alter system archive log current) with a cron job every 30 minutes.

Every time a manual log switch occurs, we see this message in the alert log:

ARC0: Failed to archive log# 2 seq# 854 However, the switch always completes a few tenths of a second later.

Would this be considered normal activity? Seems odd to see a message like this in the alert, but since we see a successful switch so quickly, I'm thinking maybe it's ok.

Thanks for any advice.

Barb

Mon Jun 24 15:55:01 2002
ARCH: Beginning to archive log# 1 seq# 841 Mon Jun 24 15:55:01 2002
ARC0: Beginning to archive log# 1 seq# 841 ARC0: Failed to archive log# 1 seq# 841
Mon Jun 24 15:55:07 2002
ARCH: Completed archiving log# 1 seq# 841 Mon Jun 24 16:55:01 2002
Thread 1 advanced to log sequence 843

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Author: Baker, Barbara
INET: bbaker_at_denvernewspaperagency.com

Fat City Network Services    -- (858) 538-5051  FAX: (858) 538-5051
San Diego, California        -- Public Internet access / Mailing Lists


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Author: DENNIS WILLIAMS
INET: DWILLIAMS_at_LIFETOUCH.COM

Fat City Network Services    -- (858) 538-5051  FAX: (858) 538-5051
San Diego, California        -- Public Internet access / Mailing Lists


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