[Ardour-Users] disk not able to keep up with ardour...

[maillistnoll]

The 4MB/sec is *not* a typo, and you are correct, the SATA drives show up as
SCSI drives. This performance number comes from the output of Bonnie++, and,
yes, I was pretty sure it was not what it should be. The drives are software
mirrored, if that makes any difference.

1) I am running Gentoo with kernel 2.6.22 (or maybe .16 - I've tried sveral)
+rt patches and the Gentoo realtime overlay packages (installs the kernel RT
patches and some other related items).

2) I'm using Ardour 2.1, though I will mention that I didn't have this
problem with 0.99x with an older version of the kernel.

3) The only other processes running are related to the desktop (KDE). I
typically don't even run things like Qjackctl. I made sure when building
this system that no servers or databases got installed, since I knew it
would be specifically used for recording. I don't even have sshd set to run
automatically.

4) I don't know about open files, but I don't think there's going to be an
extraordinarily large number. I can check this.

Note my comment about the older kernel - something like 2.6.9 without the RT
patches was working fine for up to 4-5 tracks (that's the most I tried, it
might have done more). That's why I'm wondering about the kernel tuning.

I didn't want to clutter this list with all of this, but as I said in my
first post, I can't find any resource that gives a "do it this way" guide
that is consistent with any other guide. For example, I've seen several
threads in different places about which scheduler to use for audio
recording, and they all come to different conclusions.

If someone can point me to resources that describe best practices for tuning
a system for use with Ardour I'll be glad to take it to another forum.
Arnold gave me a starting point by pointing to hdparm, but what settings
should I look at in hdparm? What other utilities and what specific settings
in the kernel do the people on this list use?

I did see a post in the Ardour forums by dcsimon that was the first
reasonably up to date "howto" that I've found. I'll be comparing my system
to that as soon as I get back home, but I note that he doesn't mention
anything about tuning the drive performance.

Thanks, again, for the help.

--kan--

 

-----Original Message-----
From: Brett Clark [mailto:Brett at ciscoinc.com] 
Sent: Thursday, December 06, 2007 12:40 PM
To: maillistnoll; ardour-users at lists.ardour.org
Subject: RE: [Ardour-Users] disk not able to keep up with ardour...

SATA drives should show up as a SCSI device, so hdparm may not be much help.
I agree that 4MB/s is slow.  Im wondering if thats a typo and should be
40MB/s even though that is also really slow for SATA.
 
I also have a 1010 and run a single dedicated SATA-1 drive for Ardour and
ive managed 18 track sessions at 24/96k before.  
 
Here's a couple of questions:
 
1) What flavor and version of Linux?  Fedora? core 4, 5, 6, 7, 8?
 
2) Are you running Ardour 2.1?   Or a previous release?
 
3) Are there other processes running at the same time?  System backups?
Databases?  Apache servers?  Can you see if you're doing a lot of swapping?
You mentioned 2 Gig of ram, so im assuming swapping isnt the issue, but it
never hurts to check.
 
4) Maybe your session has a lot of files open.  You can check with the
following:
  a) ps -ef | grep ardour  # get the PID
  b) lsof -p <pid> | wc -l   # get count of open files
 
 
Thanks
--Brett

________________________________

From: ardour-users-bounces at lists.ardour.org on behalf of maillistnoll
Sent: Thu 12/6/2007 8:06 AM
To: ardour-users at lists.ardour.org
Subject: Re: [Ardour-Users] disk not able to keep up with ardour...




I'm having trouble with my disks keeping up with Ardour. I remembered
reading this thread a while back and I've searched through some of the other
FAQs and mailing lists, but can't seem to come to any particular conclusion.

I have a 3GHz HT Intel system (Dell) with a set of mirrored Seagate SATA
drives.

Unlike the previous discussion, though, I am having trouble just getting 3-4
minutes of 3 mono tracks to record at 44.1KHz from a Delta 1010. I've run
Bonnie to test performance (approx. 4MB/sec if I remember correctly) and I
believe it should be more than sufficient, though not optimal. I've been
focusing on the IO scheduler as a possible culprit, but none of the FAQs and
other info that I've found can seem to come to any consensus whether to use
the AS, CFQ, or Deadline schedulers. My default is the AS.

Does anyone have a recommendation?

--kan--
--
Kevin A. Noll, KD4WOZ
CCIE, CCDP


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