Need Raid 5 Suggestions / Help

[infiniti_guy]

Does this card have cahcing? And how important is cahcing?

[mdmint]

Originally Posted by infiniti_guy

And are there any negatives associated with using 2 arrays as opposed to one?

Two 4 drive RAID5 arrays (using total 8 drives) would loose 2 HD storage space while one 8 drive RAID5 array would loose 1 HD storage space. You might pay less for two cheaper 4 port RAID5 controllers but by using one 8 port RAID5 controller you'd save the cost of a HD for the same amount redundant storage space plus your total storage would be 1 HD greater with one 8 HD RAID5 versus two 4 HD RAID5 arrays.

Originally Posted by infiniti_guy

It looks like the 2810SA would be the card for the 8 SATA ports.

Yup.

Originally Posted by infiniti_guy

Does this card have cahcing? And how important is cahcing?

Yes, integrated 64MB (with optional battery backup). Caching adds performance by reading ahead anticipated next needed data into fast cache and by writing to cache then to HDs as they're ready. It does greatly enhance performance, especially in our Sage usage of usually writing and reading simultaneously.

[sixdoubleo]

Originally Posted by mdmint

Since you mentioned it been looking at that mobo thinking about my next workstation upgrade. (Don't really NEED the RAID5 caching controller that's in it - Promise FastTrak S150 SX4) But for a dedicated Sage Server I wouldn't necessarily go that way. Believe better off with better more expandable caching RAID5 controller and since you in no way need AMD 64 CPU horsepower for Sage Server use AMD XP (any speed will work), spend the money saved on fastest most expandable RAID5 HD subsystem. Escalade & Adaptec have very scalable SATA solutions, Promise controllers also good IMO but not as scalable internally. My SageServer even when 5xRecording @ DVD Std and feeding play back keeps up no problem. XP 2100 CPU hardly working, 7x250 SATA RAID5 Escalade 9500S-8 w/256MB cache keep up no problem.

I forget...Is your RAID 5 IN your Sage Server? I am considering building a monster RAID 5 server and sort of using it as a SAN. basically I have Active Directory at home and plan to use a Linux RAID 5 server for storage. I'll probably go with about 1.5-2TB on the Linux box and manage it all there. Then use Active Directory DFS to basically "present" it to my Windows network.... So I'd have a DFS share like \\MyDomain\Media\PVR that Sage would record to. Of course everything will be Gigabit.

I'm just wondering what is the effect when you're viewing Live TV? I mean isn't the Sage Server writing over the network to the Linux box. Then The Sage server is READING it from the Linux box and then streaming it out to the client? 3 copies of the video stream on the netwrok? Do I have that correct?

[mdmint]

Originally Posted by sixdoubleo

I forget...Is your RAID 5 IN your Sage Server? I am considering building a monster RAID 5 server and sort of using it as a SAN. basically I have Active Directory at home and plan to use a Linux RAID 5 server for storage. I'll probably go with about 1.5-2TB on the Linux box and manage it all there. Then use Active Directory DFS to basically "present" it to my Windows network.... So I'd have a DFS share like \\MyDomain\Media\PVR that Sage would record to. Of course everything will be Gigabit.

I'm just wondering what is the effect when you're viewing Live TV? I mean isn't the Sage Server writing over the network to the Linux box. Then The Sage server is READING it from the Linux box and then streaming it out to the client? 3 copies of the video stream on the netwrok? Do I have that correct?

Yes, my main Sage 8 HD RAID5 array internal to Server. And yes Gigabit NIC should handle that traffic (and plenty more) no problem. I have similar data stream happening when the 5th tuner in main HTPC client is recording while that client also playing back and another client is playing back. BTW, if my main storage was networked I'd use two gigabits in both server & storage for data path redundancy. But that's just me, I like hardware redundancy whenever possible. Right now just have both onboard gigabit & 10/100 enabled, no slots to spare in Server for 2nd gigabit NIC

[sixdoubleo]

Originally Posted by mdmint

Yes, my main Sage 8 HD RAID5 array internal to Server. And yes Gigabit NIC should handle that traffic (and plenty more) no problem. I have similar data stream happening when the 5th tuner in main HTPC client is recording while that client also playing back and another client is playing back. BTW, if my main storage was networked I'd use two gigabits in both server & storage for data path redundancy. But that's just me, I like hardware redundancy whenever possible. Right now just have both onboard gigabit & 10/100 enabled, no slots to spare in Server for 2nd gigabit NIC

Hmmm, that just seems like lots of extra traffic to have a separate dedicated file server. I mean that's what I WANT, but consider three Sage Clients viewing Live TV....

Cable/Sat Feed into Sage Server, transferred to Storage Server. Spooled recording read from storage server into Sage Server. Spooled video streamed out to client.

Multiply that by 3, and that's a LOT of traffic on the network. I could do a deciated link between Sage Server and the storage server, but consider that my storage server is also a file server for my network as well. It's not JUST a media storage server. I'm trying to turn storage into a "commodity" on my network and stop having all these "pockets of stroage" all over the place that I need to manage.

Ideas???

[mdmint]

Originally Posted by sixdoubleo

Hmmm, that just seems like lots of extra traffic to have a separate dedicated file server. I mean that's what I WANT, but consider three Sage Clients viewing Live TV....

Cable/Sat Feed into Sage Server, transferred to Storage Server. Spooled recording read from storage server into Sage Server. Spooled video streamed out to client.

Multiply that by 3, and that's a LOT of traffic on the network. I could do a deciated link between Sage Server and the storage server, but consider that my storage server is also a file server for my network as well. It's not JUST a media storage server. I'm trying to turn storage into a "commodity" on my network and stop having all these "pockets of stroage" all over the place that I need to manage.

Ideas???

Just do the math. A gigabit nic has theoretical bandwidth of 1,000,000,000 bit/second upstream and downstream simultaneously. For this example I'll use only 50% efficency. Let's say you record everything at Max Qual 5.xGB/hr, let's make it an even 6GB/hr. There are 3600 seconds in an hour and lets use 10 bits per byte so a single record stream would use 6,000,000,000GB/36000sec*=1,666,667B/s*10b/B=16,666,667b/s per Max Qual data stream. So @ 50% gigabit capacity (1,000,000,000*.5b/s)/16,666,667b/s=30 Max Qual recording data streams each direction (upstream and downstream) @ 50% gigabit nic efficiency. When you start using more than 30 tuners I'd be worried.

Now if also using for general file server you'll hit a potential problem not from NIC bandwidth but RAID array itself. Specifically if you initiate a huge multi-gig transfer off the server and then attempt to start a record or even just new connect with a Client you may see a problem. The single array could be tied up doing the file xfer and not respond to other requests until file xfer done. (I've experimented with this on my Sage server and that is in fact what I've observed happening) Since it's not something I normally do, just occasionally pulling a recorded file from Server to my workstation and the like, I just don't do it while Sage recording and haven't looked into an automatic solution.

[Cayars]

That when you want to start implementing QOS into your network

[mdmint]

Originally Posted by Cayars

That when you want to start implementing QOS into your network

Except I don't think it's a network bottleneck, it's the RAID array itself being tied up servicing the large file xfer. Gigabit NIC has more bandwidth than single SATA RAID5 array. Though I could be wrong on the why a Client can't connect while large file xfer happening... I do know as soon as the file xfer is completed the Client can connect. I also know that during the xfer the gigabit nic usage is around 20%. I also can ping the server fine during the xfer so nic responding.

[sixdoubleo]

Originally Posted by mdmint

Just do the math. A gigabit nic has theoretical bandwidth of 1,000,000,000 bit/second upstream and downstream simultaneously.


=30 Max Qual recording data streams each direction (upstream and downstream) @ 50% gigabit nic efficiency. When you start using more than 30 tuners I'd be worried.

Yeah, mathwise it works out....I just have a natural tendancy (as Im sure you do) to try and eliminate unnecessary traffic and optimize performance. Just bugs me to know that I'm streaming this thing three ways before it gets to the client.

But when I weigh that against the total managability I'll have, the managability wins.

Guess I'm gonna start the planning....

[infiniti_guy]

Was looking at other RAID controllers... this one looks like it is at a good price point, holds 6 SATAs internal... $278 at Newegg.

LSI MEGARAID SATA 150-6
It has 64MB ECC Cache.. Hot Swap, and some other stuff... I'm not sure about the adding drives later... could be a problem as I don't see OCE support. This means I would have to setup all 6 drives at one time correct?

Anyone have experience with LSI?

Here's a link to the specs...
http://www.lsilogic.com/files/docs/m...50-6_Final.pdf

[mdmint]

Originally Posted by infiniti_guy

Was looking at other RAID controllers... this one looks like it is at a good price point, holds 6 SATAs internal... $278 at Newegg.

LSI MEGARAID SATA 150-6
It has 64MB ECC Cache.. Hot Swap, and some other stuff... I'm not sure about the adding drives later... could be a problem as I don't see OCE support. This means I would have to setup all 6 drives at one time correct?

Anyone have experience with LSI?

Here's a link to the specs...
http://www.lsilogic.com/files/docs/m...50-6_Final.pdf

Don't have personal experience with LSI RAID controllers, just 3ware, Promise & Adaptec. However, the specs DO list OCE and RAID Level Migration. Raid level migration is different than expansion. Migration means you can start with two drive RAID1 (mirror), later add a third drive and migrate to 3 drive RAID5. Expansion then comes into play adding fourth drive etc. It's a nice feature I actually used with my Promise S150 SX4 controller on my workstation. Initially setup a 2 drive RAID1 (mirror) migrated and expanded on the fly to 4 drive RAID5.

[infiniti_guy]

You're right it does have OCE, cool. It carries a lower price and seems to support a wide variety of OS.

Hey, do you guys run RAID on your TV drives, or just for other media, like DVDs, Music, etc.?

[mdmint]

Originally Posted by infiniti_guy

You're right it does have OCE, cool. It carries a lower price and seems to support a wide variety of OS.

Hey, do you guys run RAID on your TV drives, or just for other media, like DVDs, Music, etc.?

Uh, if you click on my Server/Client pic's & spec's sig line you'd see my Sage Server is using 1.495TB Raid5 array. Yeah, it handles 5 record & 3 Client playback concurrently DVD Std Q no problem.

[infiniti_guy]

I spoke with Ingraham Micro Tech Sup and they said LSI is Dell's supplier for RAID solutions. So this may be another good alternative.

[edgley]

So it seems that the choice of card comes down to 2:

3ware 9500S $300
- batt. back up, no online expansion yet

Adaptec 2810SA $460
- online expansion

I am presuming that you can still add a disk to the 3ware one, but it needs to take the array offline to install it?

[infiniti_guy]

I don't think those are comparable prices. The 3Ware $300 card only has 4 SATA ports, while the the 2810SA has 8 SATA.

The 8 SATA card from 3 Ware runs $450 (although the pics off Newegg show that th 9500S-8MI doesn't have SATA directly on the board).

Also, the LSI card (with 6 SATA) is $290 and has OCE.

[stanger89]

Originally Posted by edgley

I am presuming that you can still add a disk to the 3ware one, but it needs to take the array offline to install it?

You need to destroy the array to add another disk without OCE.

[mdmint]

Originally Posted by stanger89

You need to destroy the array to add another disk without OCE.

And if you're unclear, destroying array also means destroying all data on existing array. (not referring to you stranger89)

[edgley]

Thanks Guys,

Guess that means Adaptec for me!

[salsbst]

Is there any drawback to the 2810SA (other than price)? It seems a lot of people were recommending 3ware, and yet in my research I can't find any reason to choose anything other than the Adaptec 2810SA (if you're not sitting on a whole bunch of PATA drives).

Is the 2810SA compatible with the SATA backplane for the Chenbro RM312 case?