Re: Looking for Suggestions - 5 TB DB WHSE Backup options

Duplexing wouldn't make much sense since that would mean copying the same file to multiple destinations. He is probably referring to multiplexing or parallelism. There is a difference between RMAN multiplexing and parallelism and the term "stream" usually relates to the latter. RMAN multiplexing allows multiple files to be read at the same time within a single channel and defaults to 8. RMAN parallelism refers to multiple channels writing to the same destination and is often referred to as multiplexing on the media management side.

Oracle suggests that no more than 1 channel be used per tape device to prevent inefficient writes and shoe-shining.

*"Do not utilize media management multiplexing (multiple channels per tape drive). RMAN backup pieces will not be efficiently restored due to the interleaving of pieces on the same tape volume, which may necessitate the forward and backward movement of the tape."*

Seth Miller

On Mon, Aug 1, 2016 at 11:20 AM, Chris Taylor < christopherdtaylor1994_at_gmail.com> wrote:

> *Basically* - He keeps talking about Streams/Duplexing on the tape side -
> where 2 threads can write to the same tape apparently? I *think* that part
> is done on the Backup device outside of RMAN but I'm not sure how many
> channels I should allocate within RMAN to take advantage.
>
> For example I'm wondering (and I'll discuss with him) about the following
> scenario:
>
> Let's say we have 6 tapes and he's configured it to do 2 threads per
> tape. Does that mean I can open 12 channels in RMAN? I mean, I would
> assume so but I have no idea LOL
>
> Chris
>
>
> On Mon, Aug 1, 2016 at 10:44 AM, Seth Miller <sethmiller.sm_at_gmail.com>
> wrote:
>
>> Chris,
>>
>> It sounds like you are currently parallelizing the backup to disk with 4
>> channels and your NBU guy is suggesting parallelizing your backup directly
>> to tape using multiple channels and you're asking how that is going to be
>> different than what you are doing now. Is this correct?
>>
>>
>> Seth Miller
>>
>> On Mon, Aug 1, 2016 at 9:31 AM, Chris Taylor <
>> christopherdtaylor1994_at_gmail.com> wrote:
>>
>>> So we ran the first FULL on Friday and it took 9 hours - so your math is
>>> excellent.
>>>
>>> We did run into an ancillary problem however and that was that Netbackup
>>> was configured to use a storage pool which filled up on the Netbackup
>>> server and caused subsequent unrelated RMAN backups to fail for other
>>> databases. So, we're working through that. Our Netbackup guy wants us to
>>> write directly to tape and use multiple streams and is going to help us
>>> configure the RMAN script to take advantage of this. I'm unclear on the
>>> relationship between RMAN threads and Netbackup streams so I'm a little in
>>> the dark on what might need to be changed at this point. Currently, I'm
>>> using 4 RMAN threads/channels to write the backup.
>>>
>>> Thanks,
>>> Chris
>>>
>>>
>>> On Tue, Jul 12, 2016 at 5:32 PM, Dimensional DBA <
>>> dimensional.dba_at_comcast.net> wrote:
>>>
>>>> It really depends on your netbackup infrastructure and your network
>>>> infrastructure in between your database server and your backup
>>>> infrastructure or your remote copy on disk and your backup infrastructure.
>>>>
>>>>
>>>>
>>>> If you have a 1GB backup network from your db server to your Netbackup
>>>> Infrastrucutre with proper tuning you can normally achieve 104MB/sec
>>>> assuming proper tuning and architecture or about 432GB/hr or in your case a
>>>> 9hr full backup.
>>>>
>>>>
>>>>
>>>> If you have a 10Gb backup network from your db server to your Netbackup
>>>> Infrastructure with proper tuning you can normally achieve 780MB/sec
>>>> assuming proper tuning and architecture or about 2.88TB/hr or in your case
>>>> a 2hr full backup.
>>>>
>>>>
>>>>
>>>> This is without any special equipment or SW licenses.
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> You also could
>>>>
>>>> 1. If you have the Oracle ASO for advanced compression then you
>>>> can also turn on compression in your RMAN backups and decrease the amount
>>>> of data that has to be transferred across the link.
>>>>
>>>> 2. look at performing mixed incrementals and partial fulls to
>>>> spread a full backup over multiple days.
>>>>
>>>> 3. Use the Incremental forever, although I wouldn’t recommend
>>>> this.
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> *Matthew Parker*
>>>>
>>>> *Chief Technologist*
>>>>
>>>> *Dimensional DBA*
>>>>
>>>> *425-891-7934 <425-891-7934> (cell)*
>>>>
>>>> *D&B *047931344
>>>>
>>>> *CAGE *7J5S7
>>>>
>>>> *Dimensional.dba_at_comcast.net <Dimensional.dba_at_comcast.net>*
>>>>
>>>> *View Matthew Parker's profile on LinkedIn*
>>>> <http://www.linkedin.com/pub/matthew-parker/6/51b/944/>
>>>>
>>>> www.dimensionaldba.com
>>>>
>>>>
>>>>
>>>> *From:* oracle-l-bounce_at_freelists.org [mailto:
>>>> oracle-l-bounce_at_freelists.org] *On Behalf Of *Ilmar Kerm
>>>> *Sent:* Tuesday, July 12, 2016 3:20 PM
>>>> *To:* christopherdtaylor1994_at_gmail.com
>>>> *Cc:* ORACLE-L
>>>> *Subject:* Re: Looking for Suggestions - 5 TB DB WHSE Backup options
>>>>
>>>>
>>>>
>>>> Hi
>>>>
>>>>
>>>>
>>>> We do "incremental forever" backups using incrementally updated image
>>>> copies that are located on a separate disk storage than the primary
>>>> database. Before updating the image copy, we snapshot the backup filesystem
>>>> to provide backup history. Also store a second copy of the archivelogs in
>>>> that same filesystem where the image copy is located - LOG_ARCHIVE_DEST_x
>>>> parameter, so no separate archivelog backup is needed.
>>>>
>>>>
>>>>
>>>> Tape is ruled out in this case and you also need either a storage
>>>> system that can do NFS, snapshots, compression (optional) and thin clones
>>>> (Oracle ZFSSA, Netapp, ...) or a filesystem that can do these things (ACFS,
>>>> ZFS, ..?). But all the steps needed (except storage snapshots) can be done
>>>> using RMAN and no 3rd party libraries are needed - just need to write a
>>>> script to orchestrate the steps.
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> Ilmar
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> On Tue, Jul 12, 2016 at 7:42 PM, Chris Taylor <
>>>> christopherdtaylor1994_at_gmail.com> wrote:
>>>>
>>>> Ok, guys & gals, I'm looking for suggestions for the following
>>>> challenge. I'm very familiar with RMAN fulls w/ incrementals writing
>>>> either to disk or directly to tape. What I'm NOT familiar with is other
>>>> options that I may not know of and that's where I need your help.
>>>>
>>>>
>>>>
>>>> Objective:
>>>> Nightly backups of 5 TB Data Warehouse that is currently being
>>>> snapshotted weekly at the SAN Layer instead of tape or disk based backups.
>>>>
>>>>
>>>>
>>>> Hardware/OS:
>>>>
>>>> IBM XIV Storage (not sure of model #)
>>>>
>>>> RedHat Linux OS (5.x)
>>>>
>>>> Oracle 11.2.0.4
>>>>
>>>> Netbackup is tape solution
>>>>
>>>>
>>>>
>>>> Method Options:
>>>>
>>>> 1. RMAN Fulls on Weekend, (either to disk or direct to tape) with
>>>> nightly incrementals. I'm leaning toward disk based backups which are then
>>>> written to tape and using parallel threads for the disk based backup to
>>>> prevent overwhelming our tape library
>>>>
>>>>
>>>>
>>>> 2. Other options?
>>>>
>>>>
>>>>
>>>> Chris
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> --
>>>>
>>>> Ilmar Kerm
>>>>
>>>
>>>
>>
>

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