IDS Forum

Re: Recovery Point with Informix IDS

Posted By: Madison Pruet
Date: Sunday, 15 February 2009, at 7:26 p.m.

In Response To: Re: Recovery Point with Informix IDS (Fernando Nunes)

With HDR/RSS, all that is replicated is the logical log. With a disk b=
ased
replication solution, you end up not only replicating the logical log, =
but
the physical log, and all page flushes, Also, things which do not even =
need
to be replicated will be written to the mirrored disk, such as sort spa=
ce
and temporary tables. That means that a disk based solution uses much =
more
band-width than HDR or RSS will require.

Also, with a disk based solution, the IO is not considered complete unt=
il
the IO has been written to the replicated disk system. And finally, in
order to ensure that the copy will be able to be recovered, the disk ba=
sed
replication solution must be ordered exactly the same way on the copy a=
s it
is on the source. All of this will mean that IO writes will be rather
sluggish.

-------------------------------------
Madison Pruet, STSM
IDS Replication Architect

=

"Fernando Nunes" =

<domusonline@gmai =

l.com> =
To

Sent by: ids@iiug.org =

ids-bounces@iiug. =
cc

org =

Subj=
ect

Re: Recovery Point with Informix=

02/15/2009 05:41 IDS [14891] =

PM =

=

=

Please respond to =

ids@iiug.org =

=

=

A few comments... don't take them as a definitive or oficial answer:

- IDS 9.4 will be out of support in April 2009. IDS 10 will be out of
support in September 2010. Assuming you'll move in the 4th quarter, you=
'll
run out of support for several months, and you'll be out of support in =
less

than one year...

As for the product you mention... Apparently it's a low level disk
replication solution. If this is correct, theorectically you could use =
it
for having a failover system. But please consider that IDS has it's
internal
recovery mechanisms... And these assume some order on the I/O operation=
s...

If your disk system's replication replicates the writes in a different
order, IDS will surely fail to recover on the failover system.
Then you can ask yourself a lot of other questions... What do you want =
to
achieve? Can't you use HDR or continuos log restore do do the same? Whi=
ch
solution do you prefer of feel more confortable with?
How much is a "block"? How much data will it transfer, compared with HD=
R?
How does it handle connectivity failure?..

I don't think IDS has nothing special for this kind of technology (neit=
her
any other database) except the "blocked checkpoint" (onmode -c
block/unblock).
This can be used to get an external disk image, which you can then use =
to
make and external physical restore. It's a very nice way to get a copy =
of
your data (for HDR/RSS, for a test instance etc.). Usually people use s=
ome
ongoing disk replication and then block for a few seconds in order to a=
llow

the disk replication to assure a full synchronization).

Regards.

On Thu, Feb 12, 2009 at 4:50 PM, Achilleas Achilleos <
AchilleasAchilleos@semltd.com.cy> wrote:

> Hi to ALL
>
> First of all I would like to inform you that we are running on
Informix9.4
> FC6 and at the end of this year we are planning to move to Informix 1=
0
> (latest version).
>
> A few day ago BULL company present to as the Recovery Point of EMC
>
> What I would like to know, because is a new item (let say) , a new
> philosophy and a field that we DON'T know concerning the Recovery Poi=
nt
>
> if there is anyone that use this (Recovery Point) with Informix IDS o=
r at

> least have the knowledge to advise as if it support Informix IDS ????=
???
>
> A piece of information about this Recovery Point
>
> * RecoverPoint (for the broader enterprise)
>
> - Continuous data protection (CDP) between LUNs on the same SAN
>
> - Continuous remote replication (CRR) between LUNs across two SANs
>
> - Concurrent local and remote (CLR) data protection between LUNs
> across two SANs
>
> - Heterogeneous operating system and storage array support
>
> - Integrated with intelligent fabric from Brocade and Cisco
>
> * RecoverPoint/SE (for EMC CLARiiON and Windows)
>
> - CDP between LUNs in the same CLARiiON array in the same SAN
>
> - CRR between LUNs in two CLARiiON arrays, one in each SAN
>
> - CLR data protection between LUNs in the same CLARiiON array or
> between two CLARiiON arrays in two SANs
>
> - Supports Microsoft Windows only; no fabric integration; supports
> CLARiiON array-based splitting for heterogeneous hosts
>
> * Common functionality
>
> - Local CDP at a block level
>
> - Remote asynchronous replication (CRR) at a block level
>
> - Changes journaled to maximize the number of recovery points
>
> - Virtual and physical recovery modes optimize recovery time
>
> - Application-state integration for intelligent recovery using
> bookmarks
>
> - Dependent write-order consistency is maintained locally and
> remotely
>
> * RecoverPoint splitter drivers
>
> - Intercepts server writes (block level)
>
> - Resides on host, CLARiiON or in fabric
>
> - Mirrors write to RecoverPoint appliance
>
> * RecoverPoint appliance
>
> - Manages and prioritizes resources
>
> - Compresses data for WAN transfer
>
> - Distributes changes to remote site
>
> - Manages recovery processes
>
> - Supports instant access to protected data
>
> - Distributes replicated data to Journal
>
> * Journal
>
> - Tracks all data changes to every protected LUN
>
> - Utilizes bookmarks for application-aware recovery
>
> - Repository for live data updates
>
> - Provisioned from existing SAN LUNs
>
> - Dynamically compressed, which saves storage
>
> * Provides advanced functionality
>
> - Policy-based bandwidth management
>
> - 3-10x data compression
>
> - Lowers cost of IP infrastructure
>
> * Supports heterogeneous environments
>
> - Works with EMC and third-party storage
>
> - True any-to-any volume replication
>
> Regards
>
> Cooperative Computer Society (S.E.M) Ltd
>
> 1306 Nicosia
>
> P.O.B. 25037 CY
>
> Tel: +357 22 673 901
>
> Fax: +357 22 672 774
>
> Achilleas Achilleos
>
> Official A
>
> OS and Databases Management
>
> AchilleasAchilleos@semltd.com.cy
>
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> --Boundary_(ID_kA7uahz+FhCqZCyKDefODw)
>
>
>
>
***********************************************************************=
********

> Forum Note: Use "Reply" to post a response in the discussion forum.
>
>

--
Fernando Nunes
Portugal

http://informix-technology.blogspot.com
My email works... but I don't check it frequently...

--001636c5bf2c4c8b240462fd9d3c

***********************************************************************=
********

Forum Note: Use "Reply" to post a response in the discussion forum.

=

Messages In This Thread

• Recovery Point with Informix IDS
  Achilleas Achilleos -- Thursday, 12 February 2009, at 11:50 a.m.
  • Re: Recovery Point with Informix IDS
    Fernando Nunes -- Sunday, 15 February 2009, at 6:41 p.m.
    • Re: Recovery Point with Informix IDS
      Madison Pruet -- Sunday, 15 February 2009, at 7:26 p.m.

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