Dream/Reality RAID Fileserver/HD Sage Server

[salsbst]

Originally Posted by korben_dallas

You are choosing RAID 5/6 because of fault tolerance, correct?

Because it is not necessarily better performance. If you are wanting performance, then I'd be inclined to look into JBOD if I were you. Alot of RAID cards will do JBOD now, and if a drive crashes, you only lose the files on that drive (not the whole RAID volume).

A good controller will do RAID 5 faster than JBOD, and the more disks you have, the faster the array under RAID 5. JBOD is basically only as fast as the disk on which it is currently writing.

[ToxMox]

I just wanted to point out regarding some of the stuff said ealier in this thread regarding bottlenecks recording HD etc.

I am currently running two HDHomeRun devices on my current Sage server not even the new one being built and even while recording 4 TS streams and some SD streams my CPU usage has barely gone up at all. Only bump in CPU is from playback of the TS via the Purevideo Decoders on the server making CPU usage around 40% - 50% while recording and playing back.

So I have no doubt in my mind that my new server will work wonderfully with the HD tuners etc.

[salsbst]

FYI, I don't know where you are in your process, ToxMox, but I just discovered that some 10-20 second pauses during playback were solved (I think, I hope, but so far so good) by disabling tagged command queuing on my Areca volume. (This is a 6-drive RAID 6 set using SATA 150 NCQ drives.)

It seems that under my load (which can theoretically be as high as 3 HD streams being recorded while 2 are playing back), the TCQ algorithm was sometimes starving the playback streams.

I tried to solve this with NumBuffers and BufferSize registry settings in Sage, but for some reason, that didn't seem to do the trick. Perhaps I never bumped them high enough, but my clients only have 512MB RAM, so I believe there's only so far I can reasonably go down that path.

[ToxMox]

Thanks salsbst. I'll keep that in mind if I have that problem when the time comes. I plan on getting the newer ARC-1261ML so maybe the newer processor on the card won't have that problem. I haven't gotten much farther yet with this build. The motherboard is coming in the next couple of weeks and the rest will wait until I move into my house.

[salsbst]

Grrr. I got some delays this morning while watching The Wire when Sage started to record The Today Show in HD.

So it looks like I haven't totally solved this problem. I wonder if there's some way to control how Windows or the card allocate their efforts in order to keep the playback streams from starving?

[Spratley]

I'm in the process of setting up a similar server.

Tyan s2915
Dual 2212 Opteron's
4 GB ram
cheap video card
Areca 1220 w/ 8 WD 500GB RE's in raid 5
Coolermaster Stacker case with 2x 5-in-3 sata hotswap drive cage
2x Corsair HX520w power supply

The server's not live yet, but here's a couple of things that I've found working with it.

1. I'm currently running WinXP Pro SP2 32bit and it only shows 2.75GB ram. I think to use all 4GB's under Windows, I'd have to use XP64bit, WinXP32 w/ SP1 or Win2003 server.

2. My PVR500 doesn't like my PCIX slots (or vice versa). It works fine in the PCI slot, but it's a tight fit between the video and raid card. I've got a HDHomeRun that I haven't had a chance to try out yet, but I'm sure it will work.

Paul

[ToxMox]

Spratley,
Does it show 2.75GB Ram during post also? If so then you have to enable memory hole mapping in the bios I believe. You may also have to enable the 3GB switch in windows. I can't google a reference for you right now but you should be able to easily find how to do it. Once you've done both those things in XP 32bit I think you'll still only see a max of 3.5GB.
That sucks about the PVR500 since I have two of them. What happened when you put the PVR500 in one of the PCIX slots? Did you have anything in the other PCIX slot at the time?

[Spratley]

No, the Bios and post all show 4GB of ram - as do a couple of different 32bit flavors of Linux, I've had loaded. I set the /3GB flag in the boot.ini file and messed with the Bios a bit, but I've still got 2.75GB reported under System Properties. I'm no computer genius, but I've come to the conclusion that 2.75GB's is all I'm going to get with WinXP32. Hopefully I'm proven wrong, but I think I'll just use WinXP64bit or Linux.

The PVR500 was the only card on the PCI-X bus. I messed with it for a while under both Ubuntu Server and SageTV's Gentoo distribution. On the Linux OS's it threw alot of java.ioExceptions (or something similar), displayed video but froze the system on channel changes. Under WinXP, the system froze or rebooted on initial liveTV playback. I didn't relized the problem was the PRV500+PCI-X slot until I started testing it with WinXP.

I think there's still hope. Hauppauge reference the same issue with the PVR150 in thier FAQ -

http://www.hauppauge.com/pages/faq/s...pvr150.html#23

- I've emailed tech support, so hopefully, their "hardware change" solution will work for the PVR500 too.

[ToxMox]

If you are up for it humor me and try the memory hole mapping setting in the bios anyway with the 3gb flag on as well then perhaps you'll get the 3.5 max that xp32 is supposed to be able to achieve.

Let me know how it goes with the PVR500 if anything comes of that.

Thanks for the info and please post if you come across any other interesting things with this board.

[gplasky]

Originally Posted by Spratley

No, the Bios and post all show 4GB of ram - as do a couple of different 32bit flavors of Linux, I've had loaded. I set the /3GB flag in the boot.ini file and messed with the Bios a bit, but I've still got 2.75GB reported under System Properties. I'm no computer genius, but I've come to the conclusion that 2.75GB's is all I'm going to get with WinXP32. Hopefully I'm proven wrong, but I think I'll just use WinXP64bit or Linux.

The PVR500 was the only card on the PCI-X bus. I messed with it for a while under both Ubuntu Server and SageTV's Gentoo distribution. On the Linux OS's it threw alot of java.ioExceptions (or something similar), displayed video but froze the system on channel changes. Under WinXP, the system froze or rebooted on initial liveTV playback. I didn't relized the problem was the PRV500+PCI-X slot until I started testing it with WinXP.

I think there's still hope. Hauppauge reference the same issue with the PVR150 in thier FAQ -

http://www.hauppauge.com/pages/faq/s...pvr150.html#23

- I've emailed tech support, so hopefully, their "hardware change" solution will work for the PVR500 too.

You'll probably run into issues with 64bit XP because all of your hardware will require 64 bit drivers and those are few and far between or problematic. I know Happauge has some beta ones out there but haven't seen many comments regarding them running with 64 bit XP. And you'll need 64 but drivers for your sound card.

Gerry

[Spratley]

Originally Posted by ToxMox

If you are up for it humor me and try the memory hole mapping setting in the bios anyway with the 3gb flag on as well then perhaps you'll get the 3.5 max that xp32 is supposed to be able to achieve.

Let me know how it goes with the PVR500 if anything comes of that.

Thanks for the info and please post if you come across any other interesting things with this board.

I tried the memory hole mapping setting in the bios along with the 3GB flag, which resulted in 2.75GB's of ram being reported by WinXP32.

[ToxMox]

OK turn off the memory hole and read this link
http://support.microsoft.com/?id=888137
so unfortunately it seems SP2 makes this limit happen in SP2. You could try XP x64 or perhaps wait for vista.

[mattdcknsn]

Originally Posted by salsbst

A good controller will do RAID 5 faster than JBOD, and the more disks you have, the faster the array under RAID 5. JBOD is basically only as fast as the disk on which it is currently writing.

I know this is a bit late, but just to let you know, The more drives you add to a RAID 5 can decrease performance of the array. I think I remember reading a max of 8 or 9 drives gives you the highest performance. After that your performance will decrease. For max performance and redundancy I would go with RAID 10. Much more expensive but maximum performance.