Advice on setting up mulitple HD setup with Sagetv

[bboldschool]

I am looking for advice on setting up a muliple hd setup for Sagetv? Just partition the whole hd(s) for recording and giving it a drive letter? or using a Raid configuration? Do you just use add new directory in Sage and move your recordings to a specific drive or can you specify which drive to save recording(s)...also does Sage recognize a usb or firewire hd the same as it does internal hd's? just trying to get some practical advice in setting up my server..to hopefully to prevent some headaches in the setup...Thanks in advance...:confused:

[robogeek]

Here is how I configured my hard drives in my Media Server:

http://www.myhtpcresource.net/modules.php?name=Sections&op=viewarticle&artid=6&page=3

Formatting multiple drives as a single Dynamic Disk is not recommended if you want to keep your recordings safe. But for everyday recordings that you don't care if you have to start all over in the event of a hard drive failure, I have found it to be very efficient and network friendly. I've had pretty darn good luck when it comes to hard drives so I figured I'd push my luck just a little further :D

If you plan on keeping your recordings and want to keep them safe, creating seperate formatted hard drives with seperate recording directories and adding these directories to the SageTV configuration is safer....if one drive fails, you would only lose the recordings on that drive. Raid would be the safest way to go if you want to keep all your recordings from being wiped out due to a hard drive failure.

Hope this helps.

[Narflex]

Sage is very flexible. Just setup each disk as a single drive letter, and format it using NTFS with 64K block sizes. You can then add each one of them to Sage through Detailed Setup.

[Mike Young]

"Formatting multiple drives as a single Dynamic Disk is not recommended if you want to keep your recordings safe. "

I can second that... just spent last weekend trying to fix and then eventually restoring from a raid array failure of a Raid 0 (stripped) 2 120GBs had about 20 ripped DVD's and about 6K Mp3's, and a bunch of game installs on it. You cant beat raid 0 for speed...it will blow your mind, but I was never able to get the data back and I tried many, many utilities.
If your budget allows, I recommend what I use, the 2 120gb stripped, but I also have a 200gb that I do not keep online, I periodically bring it up and xcopy the new/changed files off the array. Of course, you would only have to mirror what you dont mind loosing. I think its a perfect solution for short-term PVR storage, but archives should be stored somewhere else.

mike/

[rrussell]

Jeff - I have two different drives set up with 64K NTFS blocks under XP, and it gets horribly fragmented. Is there something else I need to be doing to keep fragmentation down?

One is a partition on an internal IDE drive, and the other is an external firewire.

[robogeek]

rrussell,

Do you have more than one tuner card? If so, that's where the fragmentation is coming from. Multiple recordings going to the same place at the same time will cause bad fragmentation no matter how you've formatted the drive.

Diskeeper defragmenting software can be setup to run in the background and can defragment 'on-the-fly' while the disk is being used unlike the Microsoft's built in Defrag utility. If the fragmentation is causing you noticable performance problems, then Diskeeper might be worth a shot...otherwise I would say you're fighting in a no-win situation :rolleyes2

I personally don't use Diskeeper on my PVR machine so I don't can't say how well it would work or how much impact it would have on the performance of SageTV while defragmenting and recording at the same time, but for less than $50 it might be worth a shot. I use it on my 'everyday' machine (non-PVR machine) and it hasn't caused me any problems...yet :)

You can find out more about Diskeeper at: http://consumer.execsoft.com/diskeeper/diskeeper.asp?RId=1

Good luck.

[bboldschool]

This is getting a little confusing..can someone clarify/summarize?

So if you have multiple tuners can you set each different tuner to a specific hd or partition..to prevent this fragmentation occuring?

Is this cpu releated? because I know the p4 hyperthreading can process numerous tasks at once..decreasing the risk of fragmentation??

I basically have a p4 system and mb with 4 possible EIDE hd which is normal..plus I have 4 sata ports..for a total of 8 hd's...and 8 usb ports...6 pci slots...I am using this server only for recording programs and archiving the ones that I want to keep...nothing else...I have plans to have 6 tuners...maybe if that is feasible...I appreicate any further advice regarding this setup...ect....thanks:)

[robogeek]

Hey there bboldschool,

I'll try to clarify the fragmentation issue a little more...

Originally posted by bboldschool
[B]This is getting a little confusing..can someone clarify/summarize?

So if you have multiple tuners can you set each different tuner to a specific hd or partition..to prevent this fragmentation occuring?

Not exactly. You can have multiple hard drives and/or partitions assigned in SageTV (Detailed Setup-->General-->Video Directories), but I believe SageTV treats them as one big lump of storage space. Once one is full, SageTV starts filling up the next...I am assuming. Jeff, Dan, or someone that has multiple Video Directories set up would have to clarify this one.


Is this cpu releated? because I know the p4 hyperthreading can process numerous tasks at once..decreasing the risk of fragmentation??

Not really CPU or hyperthreading related as far as being a cause of fragmentation, but fragmentation can cause performance slow downs that will be more noticable on slower processors and machines with slower hard drives. Other than that, fragmentation really doesn't have anything to do with the CPU. Fragmentation of your Windows partition (the operating system files and swap file) is what will cause the most noticable slow downs. With 1GHz+ machines, fragmented media files on a seperate hard drive shouldn't affect performance too much...although, if you experience audio/video sync problems or choppy recordings or choppy video playback, fragmentation can be the cause of these. Otherwise, I wouldn't worry too much about it.

You've probably seen the recommendations to format your hard drives that store video with NTFS and 64K blocks. In theory, formatting with 64K blocks means that the smallest possible file fragment will be 64KB in size. Formatting with the default settings (4K blocks) would mean that it would be possible to have file fragments of 4KB. That could mean up to 16 times as much fragmentation...in theory. I do believe that the way Windows NT/2000/XP handles NTFS and file storage is intelligent when it comes to caching and writing files to the hard drive. Far be it from perfect, it yields much better results than Windows 95/98/ME and FAT32 format.

If anyone is curious, I'm not having any problem with fragmentation. That's not to say I don't have fragmentation, it's just not causing me any noticable problems. Here are some details from the Analysis Report (from Disk Defragmenter in the Computer Management console in Windows XP) after analyzing the volume I store my SageTV recordings on:

Volume Size: 468GB
Cluster Size: 64KB
Used Space: 220GB
Free Space: 248GB
Total Fragmentation: 47%
File Fragmentation: 94%
Total Files: 211
Avg File Size: 1.1GB
Total Fragmented Files: 185
Total Excess Fragments: 119,606
Avg Fragments per file: 568

I have several recordings that are broken into 1000 to 3000 fragments, and one football game recording that was broken into over 9000 fragments! Even with this kind of fragmentation, I haven't noticed any a/v sync issues, choppy recording, or choppy playback. The severe fragmentation is due to the fact that there are sometimes mpeg streams from 3 tv tuners being sent to the same hard drive at the same time...but as I said, I haven't had any problems with it. I'm running SageTV on an AMD 2000XP with only 256MB RAM, ATA100 7200RPM hard drives, 2 PVR-250's, and 1 DVCR network encoder. I should also mention that this machine is a dedicated SageTV server. I don't have any other unnecessary applications installed and I only use the computer to tweak SageTV and occassionally watch a show.

Hope this helps :)

[rrussell]

Hi guys -

Good questions! Just one tuner, and the recycle bin is indeed turned off.

It hadn't occurred to me at the time, but there was some pretty hairy tearing and stuttering while watching a recorded football game, esp. during the faster camera action. I wonder if that was due to the fragmentation. Hm.

Diskeeper might be a thought. We use it at work, but I hadn't thought about it for home.

Thanks,
R

[rrussell]

OK, excellent.

I downloaded a trial version of Diskeeper (http://www.diskeeper.com/coverpage.asp) and installed it last night. They've improved it to no end since we had it here at work.

Overnight it had defragged both my video partitions AND my system drive, and recording had gone on as normal. I don't have to think about it. The only drawback is that during configuration, I can't see even CLOSE to the entire program window on my TV since resolution is set to 800x600. Oh well, I just need it to run in the background anyway

I'm digging this. Thanks for the suggestion, robogeek! :D

R