Veritas Storage Foundation 5.1 SP1: Storage and Availability Management for Oracle (5900-1504, April 2011)

Similarly, Veritas Storage Foundation for DB Flashback technology creates logs
that can be used for quick recovery from database corruption by restoring a
database to its state at a previous time. Flashback logs are normally kept for a
shorter period than archived database logs. If used at all, they are typically used
within a few hours of creation. Two or three days are a typical Flashback log
lifetime.
The rapidly decaying probability of use for archive and Flashback logs suggests
that regular enforcement of a placement policy that relocates them to lower-cost
storage after a period of inactivity can reduce an enterprise’s average cost of
online storage.
For example, a customer could be using a large OLTP Oracle database with
thousands of active sessions, which needs to be up and running 24 hours a day
and seven days a week with uptime of over 99%, and the database uses Flashback
technology to correct any accidental errors quickly. The database generates large
number of archive logs per day. If the database goes down for any reason, there
is business requirement to bring the database back online and functional within
15 minutes. To prevent Oracle log switch delays during transactions, the archive
logs need to be created in a fast EMC array. Archive logs older than a week can be
moved to a mid-range Clarion array. Archive logs older than 15 days can be moved
to slow JBOD disks. Archive logs are purged after 30 days. Current Flashback logs
are created manually by the database administrator on fast EMC storage and can
be moved to Clarion storage after two days. The database administrator then
deletes the Flashback logs after a week. To set up a system like this, see the
following example. Assume that archive logs and Flashback logs are created on
the same file system, /oralog. On the file system, /oralog/archive1 contains archive
logs and /oralog/flashback contains Flashback logs.
Figure 15-1 illustrates a three-tier volume configuration that is suitable for
automatic relocation and deletion of archive logs and Flashback logs.
SmartTier for Oracle use cases
SmartTier for Oracle file-based use cases
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