Re: Cron management...
From: Hans Forbrich <fuzzy.graybeard_at_gmail.com>
Date: Wed, 22 Apr 2015 09:06:23 -0600
Message-ID: <5537B8EF.8040608_at_gmail.com>
On 22/04/2015 8:41 AM, Mladen Gogala (Redacted sender mgogala_at_yahoo.com for DMARC) wrote:
> On 04/22/2015 09:54 AM, Hans Forbrich wrote:
>>
>> From the docs: "An RMAN channel represents one stream of data to a
>> device, and corresponds to one database server session." More in
>> depth at
>> http://docs.oracle.com/database/121/BRADV/rcmtunin.htm#BRADV170
>> discusses the processes involved in reading and writing.
>>
>> I agree with Freek - the channel is on the database machine. It is a
>> server process and effectively does a form of 'direct path IO' with
>> the database. At least some portion of the MML must be on the DB
>> server machine.
>>
>> That said, it is possible for the channel to communicate across the
>> network with remote tapes and remote media software - such as
>> Oracle's Secure Backup, which acts as an MML. This is discussed in
>> the in-depth section of the docs - although there are large gaps in
>> the details.
>
> Hans, I was commenting on the proposal to have the MML on the 3rd node
> and do backups of all database from that node. We seem to have lost
> track of the original proposal.
>
Date: Wed, 22 Apr 2015 09:06:23 -0600
Message-ID: <5537B8EF.8040608_at_gmail.com>
On 22/04/2015 8:41 AM, Mladen Gogala (Redacted sender mgogala_at_yahoo.com for DMARC) wrote:
> On 04/22/2015 09:54 AM, Hans Forbrich wrote:
>>
>> From the docs: "An RMAN channel represents one stream of data to a
>> device, and corresponds to one database server session." More in
>> depth at
>> http://docs.oracle.com/database/121/BRADV/rcmtunin.htm#BRADV170
>> discusses the processes involved in reading and writing.
>>
>> I agree with Freek - the channel is on the database machine. It is a
>> server process and effectively does a form of 'direct path IO' with
>> the database. At least some portion of the MML must be on the DB
>> server machine.
>>
>> That said, it is possible for the channel to communicate across the
>> network with remote tapes and remote media software - such as
>> Oracle's Secure Backup, which acts as an MML. This is discussed in
>> the in-depth section of the docs - although there are large gaps in
>> the details.
>
> Hans, I was commenting on the proposal to have the MML on the 3rd node
> and do backups of all database from that node. We seem to have lost
> track of the original proposal.
>
Issue here is the definition of BackUp. Unfortunately, I have run across too many people who believe the RMAN executable actually does the work of backing up the database. My post was to allow access official references on the process.
As for central 'back up', the referenced doc mentions Oracle Secure Backup, which is also a centralized mechanism similar in nature to other commercial products. From that perspective, it is useful to look at Oracle's implementation of what you describe, and that is available at http://docs.oracle.com/cd/E16926_01/doc.121/e16564/osb_rman_backup.htm#OBADM187
/Hans
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