topic Re: Shadowing two disk with different size in Operating System - OpenVMS

Shadowing two disk with different size

Luis_139 — Thu, 06 Oct 2005 14:49:15 GMT

Hi All,

For OpenVMS 7.3, How can I initialize one disk with less blocks? I mean.

I need to shadowcopy a disk with 35556389 blocks to another new one. This new one has 35557376 (1029 more), but I need just 35556389 for ShadowCopy.

Is it possible to initialize this new disk with just 35556389 blocks in order to be shadowcopied? If so, please send me the command line sentences

By now, we cannot upgrade to 7.3.2 and backup-restore is not an option because we have to migrate 300 GB in less than 3 hours.

Thanks in advance.

Re: Shadowing two disk with different size

Ian Miller. — Thu, 06 Oct 2005 15:00:14 GMT

Same question as here
http://www.openvms.org/phorum/read.php?f=6&i=948&t=948

Disks are on a HP MA8000 disk array and Luis wants to move to a Hitachi 9570V

Re: Shadowing two disk with different size

John Gillings — Thu, 06 Oct 2005 16:36:01 GMT

Luis,
Sorry, dissimilar size shadowing is minimum V7.3-2.

The installation of V7.3-2 is fast, simple and is completely transparent to application software. It's little more than a large patch.

You *may* be able to fiddle this on a controller but that's a very poor second best to doing it properly.

Re: Shadowing two disk with different size

Luis_139 — Thu, 06 Oct 2005 19:27:04 GMT

Hi Jhon,

thanks for your help, as I have already notice upgrading to 7.3.2 is the best choice but it is our last option.

Could you explain a little more what is that other procedure (the fiddle one) you wrote about?? Maybe it could be the only option we have

Thanks a lot

Re: Shadowing two disk with different size

Mike Reznak — Fri, 07 Oct 2005 00:53:10 GMT

Hi,

here is fairly old answer from OpenVMS wizard.

http://h71000.www7.hp.com/wizard/wiz_4715.html

It probably won't bring more light into your case.

Mike

Re: Shadowing two disk with different size

Allan Bowman — Sat, 08 Oct 2005 12:29:06 GMT

Is this VAX or Alpha? I have used a product called MagicDisk on a number of microVAX systems in the past (VMS v5.3 through v6.2) - unfortunately it is not available at all for Alpha, but it is still supported on VAX (at least to 7.3). The product allows you to create container disks (virtual disks) on a volume so that you could shadow different sized disks. We used it to create a shadow set between an RZ26 and an RZ28 where the shadow disk looked like an RA82.

Allan

Re: Shadowing two disk with different size

Ian Miller. — Sat, 08 Oct 2005 14:03:40 GMT

If you want to try container files then LD is also available.
http://h71000.www7.hp.com/freeware/freeware70/ld/