Report of a Data Management upgrade project

[dlandrum]

I found many posts of people asking questions about Data Management, but not reporting what they actually did. Here I will try to report what I did and my lessons learned.

Parameters:
I rip DVDs to disk, yet I delete them after watching.
I had a SageTV Client hosting the disks I used for DVDs (200,200,250) .. old TV disks.
I have 2 HDHomeruns (HDHR) = 4 HD streams.
I have 2 SD MPEG tuners.
I have 3 Sage clients streaming HD content.
I had the following disks: 4x 500GB, 2x 200GB, 250GB, 300GB. I bought 2 more 500GB.
I want to maintain as few systems as possible (current 8 and that is too many)


Annoyance:
I found that if I just let SageTV write shows to any hard drive that it would record all 4 HD tuners to the same hard drive if it had the most free space. All of the shows recorded at that time would be fragmented. So, I mapped each HDHR to a 500GB disk. Then I was periodically changing that around because the disk for the primary tuner would fill-up faster than the others.


The Domino:
I got a Sage HD Media Extender (HDME) which resulted in my 'DVD' computer moving to the server room. I plan to replace all of my clients with HDMEs in order to reduce the number of computer I maintain. Before the HDME, the DVD computer only had to be on when that TV was on. Now it needs to be on 24x7 … and we can see DVDs in any room. Nice bonus. I do not want 2 servers to maintain.


Objective:
Have one Media server.
Have a solution where there is protection from drive failure.
Have a solution that supports all tuners recording and all TVs streaming HD.


Research:
I looked at NAS, but that is another server for me to maintain.
I looked a converting my server to Windows Home Server … Yet the way it uses drive space is the same as Sage, so I felt the gain was minimal to the issue at hand.
That left attached storage or bigger drives. My issue with bigger drives is that you just have more to loose when one fails, and the situation of too many streams per drive still exists.

I really liked the concept of the Drobo. Ultimately, I did not feel it could meet my performance requirements.
So that left external SATA, USB, or Firewire.


Purchase:
I decided to get an external eSata box; the Norco DS-500.
Winning factors: bundled eSATA card that I knew they would support, sturdy design, similar performance to its competitors.
Factors I tolerate: No S.M.A.R.T. notices, it is very loud.
It was a very comforting install. It took 30 minutes from opening the box to completing the drive configuration. Note: I did read the online documentation whilst it was shipping.


Security vs. Reality:
I built a hardware Raid 5 array with 5x 500GB disks. I started recording 3 HD shows and streamed 2 of them from the clients … fragmentation. This failed the minimal performance requirement.

At this point let me state that I received sign-off from the wife that it is OK to loose some TV shows due to a drive failure.

I then setup a Raid 0 (stripe) across 2x 500GB drives. I repeated this again to have 2 sets of 1TB stripes. The logic being that worst case I would loose 1/2 my TV data if one drive failed.
Repeated the test and saw no issues. I added to the test 2x SD recordings and the 3rd HD client in the house. No issues.

To me this confirmed that the first failure was not due to: cpu, memory, network, or eSata card bandwidth.

If money were no object, I think Raid 0+1 would work: buy 8 drives, build 4 hardware Raid 1 (mirror), then using XP dynamic disks build a single stripe across the 4 disks. This would provide security if any one drive failed. I would need another DS-500 ($420) and 3 drives ($340) more than the Raid 5 setup. This would cost $760 more than a Raid 5 array with the same redundancy. Maybe the $760 could be spent on a better eSata card or enclosure that could perform better?


Results:
1TB Raid 0 stripe (2x 500GB) - TV shows
1TB Raid 0 stripe (2x 500GB) - TV shows
2x 500GB - DVDs
200GB Raid 1 mirror (2x 200GB) - secure data
250GB and 300GB sitting on a shelf until I need the space (zero power draw)

I hard coded HD tuner 1 and HD tuner 4 to one stripe. I hard coded HD tuner 2 and HD tuner 3 to the other stripe. I expect them to grow at about the same rate.
I built the Spanned volume with the thought that if one drive fails I can likely recover some data on the surviving disk using data recovery tools. I have not tested this.


Summary:
I really wish I could have gotten Raid 5 to work. Oh well.
If one of the 200GB disks fails in the mirror, I would likely buy two 500GB to create the new mirror …. Then it is only 2 more disks after that to create two Raid 5 arrays (5x 500GB).

I have a dedicated closet for my servers, so the noise is not a factor, yet I may open-up the box to see what the noise is from.

In my experience it seems consistent that the number of disks needed is: (# HD tuners + (#SD tuners)/2 + #HD clients + (#SD clients)/2) / 2


The end.

[stanger89]

Originally Posted by dlandrum

Purchase:
I decided to get an external eSata box; the Norco DS-500.
Winning factors: bundled eSATA card that I knew they would support, sturdy design, similar performance to its competitors.
Factors I tolerate: No S.M.A.R.T. notices, it is very loud.
It was a very comforting install. It took 30 minutes from opening the box to completing the drive configuration. Note: I did read the online documentation whilst it was shipping.


Security vs. Reality:
I built a hardware Raid 5 array with 5x 500GB disks. I started recording 3 HD shows and streamed 2 of them from the clients … fragmentation. This failed the minimal performance requirement.

Please define what you mean by "hardware" RAID-5, the cards that ship with Norco enclosures are NOT hardware RAID controllers.

At this point let me state that I received sign-off from the wife that it is OK to loose some TV shows due to a drive failure.

I then setup a Raid 0 (stripe) across 2x 500GB drives. I repeated this again to have 2 sets of 1TB stripes. The logic being that worst case I would loose 1/2 my TV data if one drive failed.
Repeated the test and saw no issues. I added to the test 2x SD recordings and the 3rd HD client in the house. No issues.

To me this confirmed that the first failure was not due to: cpu, memory, network, or eSata card bandwidth.

If money were no object, I think Raid 0+1 would work: buy 8 drives, build 4 hardware Raid 1 (mirror), then using XP dynamic disks build a single stripe across the 4 disks. This would provide security if any one drive failed. I would need another DS-500 ($420) and 3 drives ($340) more than the Raid 5 setup. This would cost $760 more than a Raid 5 array with the same redundancy. Maybe the $760 could be spent on a better eSata card or enclosure that could perform better?

I doubt an enclosure would make much difference, especially not with only 5 discs. However (and I realize it's too late now) for about $100 more than you spent, you could have got a 3ware 9550SXU-8 and a 5-in-3 hot swap cage (would go in your PC), and I bet the performance would have been a lot better.

That's my tentative plan at the moment, I'll get a 9550SXU-8, a 5-in-3 hot-swap cage, and 3, 1TB drives, then (after I do a factory restore on my NAS to take advantage of the larger cluster size in V4.0) I'll transition my 8x250 array to the new controller/drives and have room for another 6TB.

Anyway, new working server, sounds like fun

[dlandrum]

You are right on the software raid 5. I knew I wanted to highlight it ... just typed too fast.

What do you think about these cards:
http://www.highpoint-tech.com/USA/rr2314.htm

http://www.addonics.com/products/hos...SA3GPX8-4e.asp

[stanger89]

Wouldn't touch either one

[dlandrum]

I continued to tweak my build.

I changed the controller card to a HighPoint 2304 which performs HARDWARE RAID.

I setup a RAID 5 array (5x 500GB drives) that is performing well.

I am able to record 4 HD shows + record 2 SD shows + watch 3 HD shows without fragmentation whilst viewing or fragmentation on the recorded shows.

I am happy enough with the results that I may build another one. We will see how things perform after a few months.

[stanger89]

FWIW, I can't find anything to indicate that card is a Hardware RAID controller, I seriously doubt it is.

Glad it's performing well though.

[BobPhoenix]

Originally Posted by dlandrum

I changed the controller card to a HighPoint 2304 which performs HARDWARE RAID.

Originally Posted by stanger89

FWIW, I can't find anything to indicate that card is a Hardware RAID controller, I seriously doubt it is.

Glad it's performing well though.

If the 2304 is like HighPoint's other cards it could be classed as Hardware assisted Raid. It probably has a chip on it to do the XOR's but the actual Raid functionality is still software. That is how the 464 and 1820A cards do it anyway.

BobP.

[mikesm]

I assume you didn't want to go the linux software raid route, but you can get very good performance that way. There are reports that windows server 2008 has MUCH improved software raid reliability and performance. You might try going down that route with the hardware you have - you might be able to make raid5 work.

[stanger89]

Originally Posted by BobPhoenix

If the 2304 is like HighPoint's other cards it could be classed as Hardware assisted Raid. It probably has a chip on it to do the XOR's but the actual Raid functionality is still software. That is how the 464 and 1820A cards do it anyway.

BobP.

Hardware XOR is what makes a hardware RAID card, a hardware RAID card.

I'm positive the 464 and 1820 aren't hardware RAID (no HW XOR). I highly doubt the 2000 series is HW raid (they don't advertise it). It looks like Highpoint finally does make some real HW RAID cards in the 3000 family, these use Intel processors and if you look at the specs you'll see "Dedicated I/O RAID Processor", a line which is absent on all the lower cards.

There's also the 3-4x price difference between a hardware RAID card and a software/firmware one.

[BobPhoenix]

Originally Posted by stanger89

Hardware XOR is what makes a hardware RAID card, a hardware RAID card.

I'm positive the 464 and 1820 aren't hardware RAID (no HW XOR). I highly doubt the 2000 series is HW raid (they don't advertise it). It looks like Highpoint finally does make some real HW RAID cards in the 3000 family, these use Intel processors and if you look at the specs you'll see "Dedicated I/O RAID Processor", a line which is absent on all the lower cards.

There's also the 3-4x price difference between a hardware RAID card and a software/firmware one.

I know I saw a reference to it and the chip I was lead to believe was doing the XOR's has a part number something like ????601 on the cards (have to look tonight). Must have been a bad review or something since I cannot find a manual on the 464 anymore and the 1820a definately doesn't make a reference to it.