Re: Would you ever recommend Shared Disk Failover for HA?

On Fri, 2024-02-23 at 02:21 -0500, Ron Johnson wrote:
> On Fri, Feb 23, 2024 at 2:02 AM Laurenz Albe <laurenz.albe@cybertec.at> wrote:
> [snip] 
> >
> > Anyway, my personal experience with a shared disk setup is a bad one.
> >
> > Imagine two nodes, redundantly attached to disks mirrored across data
> > centers with fibrechannel.  No single point of failure, right?
> > Well, one day one of the fibrechannel cables had intermittent failures,
> > which led to a corrupted file system.
> > So we ended up with a currupted file system, nicely mirrored across
> > data centers.  We had to restore the 3TB database from backup.
>
> 1. Sounds like both nodes were turned on.

Possible, but I think that's not relevant.

> 2. Couldn't this happen in /any/ SAN with redundant cabling?

I'd say yes, and the redundant cabling is irrelevant too - I just
wanted to emphasize that hardware redundancy is not enough.

The single point of failure was the file system.

Yours,
Laurenz Albe