For home use I use software raid0 on XP 64. It is amazingly faster and I really have no idea why someone would say software raid0 offers no better performance. It’s the difference from night and day. I use Acronis 2009 for my data backups, so I don’t really need a raid5, had a raid 0+1 before, and it worked just fine.

Having to really use a software raid now because I want to install Ubuntu 7.10 on my raid0 for a dual boot, and with hardware raid…I don’t want to even think about the headache I would get trying that.

This is all on a suse 10.1 box. Downside i see on the hardware raid on linux is when you add a drive to extend the array on the controller side, the os doesnt allow you to do any resizing of the drive array.

Is there a way round this or is this a limitation?

We always buy the hardware raid controller, because dell basically flog it away, and it supports raid 1 with a hot spare which is what we normally use. I have used software raid 1 before (both on the motherboard of a Abit NF7-S with the promise Sil3112 controller and on a Asus A8V deluxe with a Via VT8237 controller.)

Motherboard software raids (all those nforce, promise and via chipset boards, some tyan/supermicro actually have real raid cards from LSI and adaptec onboard) are worst that software raid in my experience. They are slow, buggy proprietary and a real hastle to recover, dont do half the things they do either.

I’ve used software raid as well, only in raid0, and it worked flawlessly in SuSE linux and still use software raid 1 in SuSE 9.3 with an adaptec SATA controller. (non raid controller).

Hardware raid is great if you have the money, and the space (my adpatec 2100S is a full PCI-X card – it’s huge in my atx case). It provides weird raid modes – raid 5/6/10/01/25/50/ you get the idea. Also there is a battery operated cache so my card has 128mb of ram on it just for the disks. In the new dell 1950 with the perc6i LSI controller, they come with 256mb cache which is really quite nice.

I think it all boils down to cost, if you can afford it, it’s awesome works flawlessly, if you don’t – ignore the raid on your motherboard – it’s not worth bugger all, use software raid.

Chris Samuel: Thanks for this, I stumbled upon dmraid last week while checking the ubuntu 8.10 blueprints, although it doesn’t seem like work has yet been done on this blueprint just yet, it has been approved and the priority is set to high. I hope this will make it into intrepid.

https://blueprints.launchpad.net/ubuntu/+spec/dmraid-support

Software RAID-5 under Linux has a single-point of failure at boot time. Either the MBR and boot files are on a non-RAID boot drive, or they sits on the first disk of the RAID array. If the boot device fails, the system will not boot (hence the name “boot device”).

A server could be booted off of cheap flash memory devices and then start/rebuild the systems RAID array. This would make the system more reliable. It could allow the system to send a call for help over the network in case of disk failure. Maintenance is then easy, people just replace drives (don’t touch the software).

I would like to set up something that was zero-skill-maintenance like the ReadyNAS.

Look at the Infrant (now Netgear) ReadyNAS products. These products are Samba/NFS/FTP/RSYNC/webDAV, DHCP, and print servers that feature disk-failure-resistant storage. The downside is that they are slow and expensive.

http://www.readynas.com/?p=214

The X-RAID appears to be just software RAID5 (ext3 + lvm2 + md + mdadm) and scripts to start RAID rebuilds. It is easy, just put drives in and the array expands or rebuilds a lost drive. If the OS is on the flash memory, it is less likely to fail, and so the system will boot and run the detection/rebuilding scripts.

I don’t know if this is best done with chroot switching, odd mount points & directory structures, or live-CD-like (and Eee-PC-like) Union-FS tricks.

Any input?