topic Re: History Logs Continuous Access in Disk Enclosures

History Logs Continuous Access

RafaelCastillo — Wed, 27 Aug 2008 19:51:33 GMT

Is there a problem if the history logs are in different disk group than the replicated data?

Do you have documentation about this subject?

Thanks

Re: History Logs Continuous Access

Uwe Zessin — Thu, 28 Aug 2008 08:19:55 GMT

I've never heard about a problem - what is your concern?

Re: History Logs Continuous Access

Víctor Cespón — Thu, 28 Aug 2008 08:29:33 GMT

If you're talking about the data files and transaction logs of a database, it's even recommended that they are in different disk groups, so you cannot lose both at the same time.

Re: History Logs Continuous Access

RafaelCastillo — Thu, 28 Aug 2008 14:54:31 GMT

Hi,

vcespon:
No, I'm talking about the history logs generated by a replication process between 2 EVAs. Thanks.

Uwe Zessin:
We just want to be sure there will be no problem when the history logs and the data being replicated are in different disk groups. Actually we have Continuos Access working with data and history logs in different disk groups but our concern is about having problems in the future with logs corruption.

If you have some docs with best practices or explaining how the history logs generated by replication process can be stored it will be very helpful.

Thanks.

Re: History Logs Continuous Access

Uwe Zessin — Thu, 28 Aug 2008 15:25:42 GMT

There are some hints in the CA documentation, but not all hardware / software combinations allow you explicit placement control for the WHL.
Today, it is recommended that you do not place the WHL onto FATA disk drives, especially if you are using the enhanced asynchronous mode (using disk space as a FIFO buffer), because this puts an additional burden on the drives.
Maybe this is what you had in mind?

Re: History Logs Continuous Access

RafaelCastillo — Thu, 28 Aug 2008 16:09:58 GMT

Thanks Uwe Zessin,

Yes, we are using enhanced asynchronous mode but the WHL is placed onto SCSI disk drives.

We will review the CA Documentation again to be sure the actual configuration is right for our needs.

Thanks for your support.

Re: History Logs Continuous Access

RafaelCastillo — Thu, 28 Aug 2008 16:19:48 GMT

The Continuous Access configuration allows to indicate a location to place the WHL, our doubt was if there will be a problem or an issue if this location is different from the location of the data that is being replicated. There are no known issues about this.

Thanks for your support.

Re: History Logs Continuous Access

IBaltay — Sat, 30 Aug 2008 20:39:02 GMT

hi,
maybe this could help:
http://bizsupport.austin.hp.com/bc/docs/support/SupportManual/c01489857/c01489857.pdf

Re: History Logs Continuous Access

RafaelCastillo — Mon, 01 Sep 2008 13:38:38 GMT

We will take a look at it.

Thanks for your help.