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MirrorDisk/UX documentation

 
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Olivier Drouin
Trusted Contributor

MirrorDisk/UX documentation

'sup

I need to learn how mirrordisk/UX works. Right now I'm reading http://docs.hp.com/hpux/pdf/B2355-90742.pdf which is a great file for recipes on how to do specific things but it doesn't explain the how's ( for mirrordisk ).

In the beginning of the chapter the author states:

###
If you would like to learn more about basic mirroring tasks, it is
suggested that you refer to the book Disk and File Management Tasks on
HP-UX published by Prentice Hall PTR, 1997.
###

which I cant find. Is there any other files/sites that I could read ??

Thanx.
O
12 REPLIES 12
Sridhar Bhaskarla
Honored Contributor

Re: MirrorDisk/UX documentation

Hi,

Look at the following document "Managing Systems and Workgroups: A Guide for HP-UX System Administrators " at docs.hp.com

http://docs.hp.com/hpux/onlinedocs/B2355-90742/B2355-90742.html

Look at "Managing Disks and Filesystems" Chapter. You should get all the information needed.

-Sri
You may be disappointed if you fail, but you are doomed if you don't try
Olivier Drouin
Trusted Contributor

Re: MirrorDisk/UX documentation

hard day @ work, huh?! -_-

Thanks but thats the file I'm talking about in my post...
Jeff Schussele
Honored Contributor
Solution

Re: MirrorDisk/UX documentation

Hi Olivier,

The HP-UX SW Recovery handbook - specifically the LVM chapter - has a good section on Mirror-UX.
Here's the link to the LVM chapter:

http://www1.itrc.hp.com/service/iv/docDisplay.do?docId=prodITRC/DE_SW_UX_swrec_EN_01_E/LVM.pdf

You can get to the entire handbook via the "Navigate Knowledge Trees" link of the ITRC home page.

HTH,
Jeff
PERSEVERANCE -- Remember, whatever does not kill you only makes you stronger!
Jeff Schussele
Honored Contributor

Re: MirrorDisk/UX documentation

And it should be noted that no *new* commands are introduced by the install of Mirror-UX, rather certain functionality (lvextend -m X for example) is introduced. So there are probably no manuals, per se, for Mirror-UX exclusively. But *any* good LVM manual will have what you want.

Rgds,
Jeff
PERSEVERANCE -- Remember, whatever does not kill you only makes you stronger!
Mic V.
Esteemed Contributor

Re: MirrorDisk/UX documentation

From amazon.com:

Disk and File Management Tasks on Hp-Ux (Hewlett-Packard Professional Books) by Tom Madell, Thomas Madell (Paperback - January 1997)
Books:
Buy new: $29.40 Used & new from $24.50 Special Order

One thing to remember about MirrorDisk: whatever you do with it, the host (computer) performs the processing. That means if you're mirroring, the process of keeping disks synchronized is being done by your computer and those resources are not available for the regular "work" that the computer is doing. That's one reason that people invest in external disk arrays (EMC, Hitachi, HP) -- they may perform RAIDing for you, thus offloading the resource drain from the host.

HTH,
Mic
What kind of a name is 'Wolverine'?
Sridhar Bhaskarla
Honored Contributor

Re: MirrorDisk/UX documentation

yeah.. It's a kind of multi-tasking day.

Jeff got the stuff for you.

Have a good day.

-Sri
You may be disappointed if you fail, but you are doomed if you don't try
Jeff Schussele
Honored Contributor

Re: MirrorDisk/UX documentation

Hi mic,

That's true to some extent, but remember most of the double-write penalty is offset by the ability to direct reads to 2 different devices - i.e. the next read is always placed on the device with the smallest queue.

But, in my mind, mirrors are about safety & availability. In our shop all our local or non-RAID storage is mirrored so drive failures do not cause us downtime.

You really have to look at Mirror-UX that way - it's not intended for performance - it's for availability. I wouldn't even think about using MC/SG w/o Mirror-UX.

My 2 cents,
Jeff
PERSEVERANCE -- Remember, whatever does not kill you only makes you stronger!
Mic V.
Esteemed Contributor

Re: MirrorDisk/UX documentation

Jeff,

How would you handle a SG cluster with a 300GB database hosted on a Symmetrix/Hitachi/XP (database only active on one node)? MirrorDisk on the host or let the array handle it?

Just trying to understand your perspective. Sorry to be off-topic.

Mic
What kind of a name is 'Wolverine'?
Jeff Schussele
Honored Contributor

Re: MirrorDisk/UX documentation

An array RAID5 of course.
Would you want to boot off of it?

Back at ya,
Jeff (Who keeps vg00 safely close to home & mirrored)
PERSEVERANCE -- Remember, whatever does not kill you only makes you stronger!