Fake Raid vs Software Raid

GogglesGuy · 2009-09-29 19:15:07

I have 4 harddrives that I like to setup in a RAID-5 configuration. My motherboard comes with one of those Fake Raid controllers (Intel ICH10R) and was wondering whether there is any advantage of using the fake raid vs regular software raid. Perhaps one is easier to setup than the other, or there may be some performance differences?. My OS will be installed on a separate harddrive, so I don't plan on booting from the raid, it will be mainly used for data storage.

lilsirecho · 2009-09-29 19:59:50

Perhaps you will get some guidance from the wiki for mkinitcpio which describes the use of mdadm raid...software raid.

Most posts regarding raid recommend using mdadm software raid.

My system has a four device raid0 for storage. It has four 45MB/s compact flash devices of 32GB total that reads in hdparm 176MB/s.

Write speed for multi files runs 30 to 40MB/sec.

So it does well for reads of large files and falls short on reads of multi smaller files.

All was expected when the system was initiated.

It assembles during initramfs and mounts via fstab /or/ one could mount it as root as needed.

Recommend mdadm for the raid0 storage. Mine has been running about a year now with 640 files, 4GB. Add to it from time to time.

Zariel · 2009-09-29 20:43:41

If you want to install windows and have raid I think you have to go fake raid, I personally went mdadm after dmraid didnt work. Mdadm is great, having email on failure is a must!

fukawi2 · 2009-09-29 22:36:54

Personally, I would go with... Wait, I've answered this before:
http://bbs.archlinux.org/viewtopic.php? … 67#p611667

Third paragraph is most relevant

Not trying being rude, but just saving me typing that same stuff over again

Last edited by fukawi2 (2009-09-29 22:37:36)

GogglesGuy · 2009-09-30 16:16:12

Thanks for the input. I guess I'll be going with plain software raid.

GogglesGuy · 2009-09-30 19:07:38

Assuming you just want to access multiple harddrives as one big virtual harddrive, you basically have 3 options:

1) LVM only

- full disk space available. add/remove/replace drives possible.
- no redundant data

2) RAID-5

- redundant data, less disk space available (n-1)
- add/remove/replace drives possible

3) RAID-5 + LVM

Is there any benefit at all for the situation I'm describing here?

fukawi2 · 2009-09-30 22:31:19

If you need to grow in the future, you can add a second RAID array, then add that to the LVM. So you'll have one LVM, with 2 separate RAID arrays under it (ie, /dev/md0 and /dev/md1)

Arch Linux

#1 2009-09-29 19:15:07

Fake Raid vs Software Raid

#2 2009-09-29 19:59:50

Re: Fake Raid vs Software Raid

#3 2009-09-29 20:43:41

Re: Fake Raid vs Software Raid

#4 2009-09-29 22:36:54

Re: Fake Raid vs Software Raid

#5 2009-09-30 16:16:12

Re: Fake Raid vs Software Raid

#6 2009-09-30 19:07:38

Re: Fake Raid vs Software Raid

#7 2009-09-30 22:31:19

Re: Fake Raid vs Software Raid

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