Mirrors

Mirrors

Post by Daniel Madvig - Systems/Analy » Sat, 28 May 1994 08:26:16



I understand that a few months ago, before I attained membership
in this august group, there was quite a discussion going on
regarding Informix mirroring versus hardware mirroring.  Sorry
I missed it.

We're having a bit of fun on our own.  Informix mirroring is NOT
working for us.  If either the primary or the mirror drive goes
offline, OLE will soon stop.  He will continue to function until
it's time to do a checkpoint.  Then STUCK CITY.  Tbstat shows
"CKPT REQ".  We shutdown OLE with "tbmode -ky", shutdown hp-ux,
reseat the edge connector on the drive, and bring the system back
up.  Whatever transactions happened till the checkpoint was
reguested get committed during the restart.

Yes, we've replaced the edge connectors, so now the drives don't
go offline, BUT (perhaps you would agree) THAT'S NOT THE POINT.  
What if irrepairable harm should befall one of the drives?

We're running 5.01 on an HP9000/842s.  The drives in question
are all on the same SCSI chain.  The fact that one drive might
be offline does not affect hp-ux operations anywhere else in
the chain.

Informix is trying to help, but they haven't gotten anywhere.

Are we the ONLY ones experiencing this?  

I'm off for a long Memorial Day holiday.  Back Wednesday
--


   Bethel College & Seminary            phone:  (612) 638-6414
   3900 Bethel Drive                    fax:    (612) 638-6001
   St. Paul, MN 55112

               If you think health care is expensive now,
               just wait until it's free.  --  Gary Bauer

 
 
 

Mirrors

Post by Daniel Madvig - Systems/Analy » Sat, 28 May 1994 08:26:13


I understand that a few months ago, before I attained membership
in this august group, there was quite a discussion going on
regarding Informix mirroring versus hardware mirroring.  Sorry
I missed it.

We're having a bit of fun on our own.  Informix mirroring is NOT
working for us.  If either the primary or the mirror drive goes
offline, OLE will soon stop.  He will continue to function until
it's time to do a checkpoint.  Then STUCK CITY.  Tbstat shows
"CKPT REQ".  We shutdown OLE with "tbmode -ky", shutdown hp-ux,
reseat the edge connector on the drive, and bring the system back
up.  Whatever transactions happened till the checkpoint was
reguested get committed during the restart.

Yes, we've replaced the edge connectors, so now the drives don't
go offline, BUT (perhaps you would agree) THAT'S NOT THE POINT.  
What if irrepairable harm should befall one of the drives?

We're running 5.01 on an HP9000/842s.  The drives in question
are all on the same SCSI chain.  The fact that one drive might
be offline does not affect hp-ux operations anywhere else in
the chain.

Informix is trying to help, but they haven't gotten anywhere.

Are we the ONLY ones experiencing this?  

I'm off for a long Memorial Day holiday.  Back Wednesday
--


   Bethel College & Seminary            phone:  (612) 638-6414
   3900 Bethel Drive                    fax:    (612) 638-6001
   St. Paul, MN 55112

               If you think health care is expensive now,
               just wait until it's free.  --  Gary Bauer

 
 
 

Mirrors

Post by m.. » Wed, 01 Jun 1994 19:05:25


ID>Are we the ONLY ones experiencing this?

Well, we have 8 drives mirrored using 4.1. Recently we had two drives
fail (same mounting kit, same dodgy connector). The backup drives took
over perfectly. When we replaced the primary drive connectors, Informix
re-mirrored (about 1GB in an hour); no interruption to service.

Works well for us, but that's not much use to you. All I can say is that
it should work...

The opinions stated are not necessarily those of the Houston BBS, or
Houston Crest, or of the person stating them. Everything is relative.

 
 
 

1. To mirror or not to mirror

Hello,
I'm installing an SQL 6.5 server..
I read somewhere that mirroring a device on SQL 6.5 is a serial proces.
My question is...
...does it affect the performance of the server...if you mirror some or all
devices?
... because you have more I/O disk access...I think it does...

All info & tips for installing and managing the SQL6.5 are welcome...

And...
In case mirroring affects the performance...Does somewhone has any
information about RAIDconfigurations

Please mail me at



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