topic Re: mirror OS in Operating System - Linux

mirror OS

Ratzie — Sun, 04 Jul 2004 00:34:11 GMT

I have just read a post saying that you can not mirror swap or /.

Why is it on the build of Red Hat it allows you to do it.

I first created 2 raid devices, then created a md that was associated with say swap, /, /tmp, /boot

I was able to create RAID 1 on all my partitions without Red Hat complaining.

Re: mirror OS

Alexander Chuzhoy — Sun, 04 Jul 2004 00:44:57 GMT

There's no problem creating mirror of / during installation.The problem is (or at least was) to do that on existing system.

Re: mirror OS

Stuart Browne — Sun, 04 Jul 2004 18:27:51 GMT

As Alexander said, there's no problem doing this.

However, why create a software-raid swap device ?! Why increase the over-head for page-memory?

RAID your /, your /boot and other filesystems, but don't bother with software RAID for a swap device. Unless you think you're going to be using alot of swap on a regular basis, the performance hit won't be worth it.

Re: mirror OS

Thomas Bianco — Tue, 06 Jul 2004 09:13:08 GMT

since swap is not persistent across reboots, there really isn'y much need to mirror swap. the only posiblity is in the event of a hard disk failure, you'd be able to keep running.

consider hardware raid though. there is less overhead on the system if the math to do the raid is done in hardware.

Re: mirror OS

Steven E. Protter — Tue, 06 Jul 2004 11:08:02 GMT

You can mirror swap.

I mirror all the partitions including swap raid 1 on my production Red Hat Servers.

I set it up with disk druid on initial install, but that is not a necessity, it can be done after installation as well.

The post, was wrong.

SEP