topic Re: Question on Mirror UX in Operating System - HP-UX

Question on Mirror UX

Fabien BARBIER — Fri, 25 Oct 2002 08:47:29 GMT

Hi,
I have a question for you, asked by one of our customers:
He has 2 distant sites,both with HP servers.
Each server has its own disk bay, disks controled by physical raid cards in the bay.
I'd like to know if mirror-ux can handle a mirror of a disk from site 1 to site 2. I made a little drawing to explain my question... Please forgive my English and my poor arstistic sense...
Thanks in advance! any answer welcome.

Fabien

Re: Question on Mirror UX

David Lodge — Fri, 25 Oct 2002 09:01:23 GMT

MirrorDisk will only mirror discs in the same Volume Group - so if the discs are on different servers then no.

If the discs are on different arrays connected to the same server then yes.

Re: Question on Mirror UX

U.SivaKumar_2 — Fri, 25 Oct 2002 09:02:04 GMT

Hi,
Using Mirror-UX you cannot span the mirror disks between the servers. But only on different controlleers in the same server.

However ,There are hardware solutions like SAN to mirror disks in remote site for disaster recover.

regards,
U.SivaKumar

Re: Question on Mirror UX

David Lodge — Fri, 25 Oct 2002 09:16:04 GMT

MirrorDisk/UX doesn't distinguish on that level - it works on the *Volume Group* level. If the server sees the discs as part of the same Volume Group it will mirror them, regardless of its eventual location - it has no idea whether the discs are next to each other or thousands of miles apart; or even if the 'disc' is actually several discs in a RAID 5 group.

This is the whole point of using SANs - to further abstract Hardware from OS.

Re: Question on Mirror UX

Fabien BARBIER — Fri, 25 Oct 2002 09:16:13 GMT

Thanks for your answers.
But I'd like a precision, or confirmation (no points until then! LOL ;-)).
We are already in a SAN environment: each server owns HBA controllers, connected to switches, themselves connected to disk bays...
I'd like to have the confirmation that mirror ux can mirror a disk from disk bay 1 to disk bay 2 (distant site), and if limitations exist (distance?).
Thanks!

Fabien

Re: Question on Mirror UX

Fabien BARBIER — Fri, 25 Oct 2002 09:19:18 GMT

Thanks

David, your 2nd answer came at the same time than my 2nd question, but it was the one I expected! Of course, I meant "volume group"...
Points awarded, topic colsed!

Cheers

Fabien