Mark, Thank you very much for that insight. I had never realized that it could cause longer latency. The machine I setup for a client was SCSI raid, so maybe that makes a difference as well. Of course, the other client that I did a special RAID for was doing video work, and they almost required a RAID. Maybe for my purposes simply have 2 drives, one for operating system other strictly for recording, would be better? In the end I will only be doing 4 different inputs max, so maybe I am overdoing it a bit. On a side note, is there any way I could get you to give me a bit more info about how you went about setting up your RAID(s)? Offlist is fine if it will be too offtopic. Don't worry about it if you don't want to. Thanks! Bryan On Wed, 26 Mar 2003, Mark Knecht wrote: |Bryan, | Actually, it's an interesting issue. I've looked just a little bit at |this. I think it depends a lot on how you do it. RAID *can* improve raw |throughput, but it *almost* *always* has longer latency, or at least the |one's that I've set up. It has seemed that in audio work latency makes at |least as big a difference as throughput, maybe more, and RAID didn't work |well for me. | | Keep in mind that a 24-bit, 44.1KHz signal is only using a bit over |120KB/S, and my current EIDE hard drive under Linux is providing nearly |45MB/S, implying the ability to supply more than 200 stereo channels. |(Assuming no seek issues, etc., which will happen.) | | However, I agree that if you have a good RAID controller that can do |speculative look-ahead operations and has lots of caching on board the |controller, it seems like it should help. | | Personally, I get 32 channels today from a single 1394 hard drive which |suits my purposes very well. I haven't had the need to push further, but do |this it would be interesting to try. | |Cheers, |Mark | |> -----Original Message----- |> From: linux-audio-user-admin(a)music.columbia.edu |> [mailto:linux-audio-user-admin@music.columbia.edu]On Behalf Of Bryan |> Koschmann - GKT |> Sent: Wednesday, March 26, 2003 1:19 PM |> To: Linux Audio Users |> Subject: [linux-audio-user] Raid setup (kinda OT) |> |> |> Hello, |> |> While I know this is specfically an audio group, I'm thinking this is |> still related, but I apologize if it is too far off topic. |> |> I was wondering if anyone here has setup an IDE raid, either via hardware |> or software. I ask because I know it usually would speed up disk access |> which is good for realtime audio work (I had to work on a scsi system with |> a layla for a customer of mine). I was looking at doing a striped raid |> with 2 80 gigs (or maybe 2 120s). |> |> I tried to setup a striping (then later a mirror) on my other machine |> running slack 8.0 but had absolutely no luck whatsoever. Neither the |> hardware on my motherboard (HPT370 on abit VP6) or just a simple software |> raid worked. I will probably be using the same board for audio recording |> unless someone has a better suggestion (looking at asus). |> |> So, if anyone can give me any recommendations or hints/tips I would be |> quite happy. :) |> |> Thanks in advance, |> |> Bryan |> |> |> |> |> |> | |

On Wed, Mar 26, 2003 at 02:13:14PM -0800, Bryan Koschmann - GKT wrote: First and foremost, download Neil Brown's mdadm package. It makes kernel software RAID a piece of cake! (apt-get install mdadm will work if you run Debian) Second: # mdadm --create /dev/md0 --chunk=X --level=0 --raid-disks=2 /dev/disk1 /dev/disk2 The chunksize is an integer parameter that set how wide the stripes are - playing with this value can change performance a lot, so definately do some benchmarking! *HOWEVER* - I wonder if you're not asking for a disaster. RAID0 has no provision of reliability. ie, if one of those disks starts having problems, you've lost all your data. I would be very reluctant to use RAID0 as permanent storage for any of my music - there's too much risk. Let me agree with other posters that it's probably overkill, especially considering the data loss potential. I do my GNU/Linux recording work to a partition that's actually a mirrored RAID1 pair (slower than a single disk) and I've never had problems. -- Ross Vandegrift ross(a)willow.seitz.com A Pope has a Water Cannon. It is a Water Cannon. He fires Holy-Water from it. It is a Holy-Water Cannon. He Blesses it. It is a Holy Holy-Water Cannon. He Blesses the Hell out of it. It is a Wholly Holy Holy-Water Cannon. He has it pierced. It is a Holey Wholly Holy Holy-Water Cannon. He makes it official. It is a Canon Holey Wholly Holy Holy-Water Cannon. Batman and Robin arrive. He shoots them.

On Thu, Mar 27, 2003 at 07:19:17PM +0700, Darren Landrum wrote: Same here :) What are the specs ? regards, v