SEO

#1 (**permalink**) 01-05-2008, 06:05 AM

I am interested in finding out what other people have setup in regards
to mirroring rootvg and the configuration of sysdump devices. I've
been reading that mirroring dump device is not a good idea. My hdisk0
and hdisk1 are mirrored to eachother. I'm thinking that I should place
a primary dump device lg_dumplv on hdisk0 and a secondary dump device
lg_dumplv_1 on hdisk1. Is this the normal configuration that you use?
If not, please give me suggestions. I am eager to learn what other
people are doing.

Cheers!

#2 (**permalink**) 01-05-2008, 06:05 AM

shpot4@yahoo.com wrote:
> I am interested in finding out what other people have setup in regards
> to mirroring rootvg and the configuration of sysdump devices.

> I'm thinking that I should place
> a primary dump device lg_dumplv on hdisk0 and a secondary dump device
> lg_dumplv_1 on hdisk1.

I think that this is a good approach.

Yours,
Laurenz Albe

#3 (**permalink**) 01-05-2008, 06:05 AM

shpot4@yahoo.com wrote:
> I am interested in finding out what other people have setup in
regards
> to mirroring rootvg and the configuration of sysdump devices. I've
> been reading that mirroring dump device is not a good idea.

I feel that it's only a space issue. If you want to mirror it, and you
have space, why not?

> My hdisk0
> and hdisk1 are mirrored to eachother. I'm thinking that I should
place
> a primary dump device lg_dumplv on hdisk0 and a secondary dump device
> lg_dumplv_1 on hdisk1. Is this the normal configuration that you
use?

Yes. Completely normal. We have two setups: either mirror hdisk0 to
hdisk1 (except for dump), or create an alt_disk_install to hdisk1.

> If not, please give me suggestions. I am eager to learn what other
> people are doing.
>
> Cheers!

#4 (**permalink**) 01-05-2008, 06:06 AM

<shpot4@yahoo.com> wrote in message
news:1110949857.185490.106140@z14g2000cwz.googlegr oups.com...
> I am interested in finding out what other people have setup in regards
> to mirroring rootvg and the configuration of sysdump devices. I've
> been reading that mirroring dump device is not a good idea. My hdisk0
> and hdisk1 are mirrored to eachother. I'm thinking that I should place
> a primary dump device lg_dumplv on hdisk0 and a secondary dump device
> lg_dumplv_1 on hdisk1. Is this the normal configuration that you use?
> If not, please give me suggestions. I am eager to learn what other
> people are doing.
>
> Cheers!
>

Yes, that is the best practice for dump device. Mirroring and using
compression will usually cause a corrupt dump, and that kind of defeats the
purpose of the dump device. I have found this out the hard way, and all my
servers are now configured with lg_dumplv and lg_dump2lv
Doug

#5 (**permalink**) 01-05-2008, 06:06 AM

Mirroring a dump device is pointless, as AIX cannot write to both
copies during the dump. It only writes to one copy. If your device is
mirrored, when you try to read the dump later, half the reads will go
to the copy that doesn't have any data, so you'll get a "corrupt" dump.
Instead, simply make a primary and secondary dump device. This is much
more useful and is the normal configuration.

Side note: AIX does make an exception for mirrored hd6 (default paging
space) as a dump device. It still only writes to one copy during the
dump, but the dump copy command on boot knows to only read to one copy.
It doesn't actually provide any mirroring for the dump, but allows you
to mirror your paging space, which you probably want to do anyways,
even if paging is your dump device. Incidentally, this is the only
mirrored dump device IBM supports. I would still recommend a dedicated
dump device over using hd6.

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

SEO

rootvg mirrored and sysdump