I setting up and testing my new server I am getting to experience a RAID rebuild quite often...

I want to check whether the rebuild times I am seeing fit with other people's experience. I have two 250GB SATA drives, running with three RAID1 arrays (50MB /boot, 1GB swap and all the rest for /).

The /boot and swap arrays resync very quickly. The main 213GB array takes over 5 hours to resync, trundling along at about 12,000K/sec most of the time.

Is this the best that I can expect ?

You can tune the parameters a bit for faster rebuilds:

http://lists.centos.org/pipermail/centos/2005-February/044484.html

Mine are set to 1000 and 200000 and my RAID5 resync is pretty fast. Of course, making it faster means slowing down the box a little bit; there's no free lunch.

It seems my Debian install is already so tweaked.

My 250gb*3 software raid5 takes literally days, but I'm pretty sure there's something wrong with the install. I'm switching to the USB enclosures mentioned in another post for the hotswapability and the ability to add them without extra IDE cards.

Anyone have a good guide to linux software raid (preferably on debian, or distribution agnostic)? I got through the setup enough to make it work when I set up the last array, but I'd like to Do It Right this time with everything optimized.

Matthew

Most of the Debian software RAID guides are out of date in one way or another I'm afraid. Almost all of them talk about the Debian installer not being able to install a working bootable RAID1 system (with / on the RAID1 array).

In fact the current installer (even in the stable version of Debian) is perfectly capable of achieving a bootable RAID1 system.

Exactly. and mdadm is a brand new thing that you should try out.

I don't actualy care about a bootable raid partition, the uptime on the server is inconsequential, it's the data that it's storing that's important.

Matthew