SWAP not in mirror

[fiorenzo monteleone]

I have a system whit all in mirror but swap area not in mirror.
What happen if there is a fault in disk of swap area and the system is in swap?
Thanks.

[Mark Grant]

The system will probably crash.

You must mirror swap.

[Pete Randall]

If you have a fault in your swap area your system is going to crash. It's always a good idea to mirror your swap area!


Pete

[fiorenzo monteleone]

I suspect this.
Thanks for your answers

[Kent Ostby]

As Pete says, you'll have a panic anyways.

The reason you need to fix this is that you won't be able to boot your mirror if your root disk dies at this point.

You need to unmirror and re-mirror to get the lvol order correct on the mirrored drive.

Best regards,

Kent M. Ostby

[T G Manikandan]

you should also mirror it.
the important file systems to name would be / /usr & swap which should definitely be mirrored.

thought the recommendation to have a primary swap which is minimum as possible and then create a secondary swap on a another hard disk which is not mirrored or not in vg00.

There are advantages like

1.Save the disk space a lot,assume you have a big primary swap and you are mirroring it.

2.Reduce the contention of I/O on the root disk if there is more swapping on the machine.

[Johan Lorimier]

Hi,

I'm not agree with T G Manikandan, even if your swap is not in VG00 you MUST mirror it (or at least having a disk architerture with data protection).

follow the advices from all the others, mirror the swap.

Johan

[Patrick Wallek]

ALL swap space, whether it is in VG00 or not MUST be mirrored. ALL processes in HP-UX attempt to reserve some amount of swap space when they start. If your swap space is not mirrored and you have a problem with that disk, then processes will not be able to reserve space. If a process can't reserve swap space, it won't start.

Now what is recommended by some is to create a separate DUMP which is NOT mirrored. You must remember here that swap and dump are NOT the same and can be configured separately.

[A. Clay Stephenson]

ANY swap space (primary or otherwise) should be mirrored or the system will die if a disk fails. If you are mirrored (and assuming you have hot-plug disks) you can replace swap or any other LVOL's without shutting down and the system will never miss a beat. The only system areas that shouldn't be mirrored are dump spaces --- and in my view of the world swap and dump have absolutely nothing to do with each other.