LinuxMCE Forums

General => Users => Topic started by: Ray_N on January 24, 2009, 12:05:44 am

Title: Newbie with Installation from Scratch
Post by: Ray_N on January 24, 2009, 12:05:44 am
Hello there guys and gals...
   I'm new to LinuxMCE (or any other media center solution for that matter), but I want to jump in with both feet and get myself soaked. And (side benefit) I want to show all my friends the power and flexibility of Linux. ;D By reading throughout the website, I've come up with this shopping list that I'm planning on buying to get me going. But before I actually plop down my credit card I wanted to check with you the experts to see if this makes any sense.

   This will be a Hybrid/Core system only for now...only serving my living room, to a 40" 1080p Samsung...Maaayybeee (big maybe) later extending to other rooms in the house. So that's why I'm not planning for another NIC since everything will be on my one network.

   Also, I'm seeing on the wiki page for the MOBO I picked (wiki.linuxmce.org/index.php/ASUS_M3N78-EM) that this board may not have best performance out of the box for UI2 with alpha blending, so I'm thinking maybe I should wait until LinuxMCE v0810 comes out.

   Any thoughts, thumbs up or down on the shopping list, anything I should change or add, or anything else will be very much appreciated.

(I'm fairly technical, as you can see I'm planning on building this myself, and have some intermediate knowledge of Linux so feel free to talk tech. Although I would prefer if I didn't have to be running a bunch of scripts or recompiling things to get everything going).
Thank you all,
R

Item
Cost
Description
Website
Case$49.99 hec  Black 0.7mm Thickness SECC 7K09 Micro ATX Media Center / HTPC Casewww.newegg.com/Product/Product.aspx?Item=N82E16811121027
CPU$78.00 AMD
  Athlon 64 X2 7750 Kuma 2.7GHz 2 x 512KB L2 Cache 2MB L3 Cache Socket AM2+ 95W  Dual-Core black edition		www.newegg.com/Product/ProductReview.aspx?Item=19-103-300&SortField=0&SummaryType=0&Pagesize=10&SelectedRating=-1&PurchaseMark=&VideoOnlyMark=False&VendorMark=&Keywords=(keywords)&Page=2
Motherboard$89.99ASUS M3N78-EM  AM2+/AM2 NVIDIA GeForce 8300 HDMI Micro ATX AMD www.newegg.com/Product/Product.aspx?Item=N82E16813131354
RAM$45.98 (2)
  Kingston HyperX 1GB 240-Pin DDR2 SDRAM DDR2 1066 (PC2 8500) Dual Channel Kit Desktop Memory		www.newegg.com/Product/Product.aspx?Item=N82E16820104012
Hard Drive$74.99Western Digital  Caviar Black WD5001AALS 500GB 7200 RPM 32MB Cache  SATA 3.0Gb/swww.newegg.com/Product/Product.aspx?Item=N82E16822136320
Bluray Player$109.99 LITE-ON  Black 6X Blu-ray DVD-ROM 16X DVD-ROM 48X CD-ROM SATA Internal 6X Blu-Ray DVD  ROM & 16X DVD±R DVD Burner Model iHES106-29 - OEMwww.newegg.com/Product/Product.aspx?Item=N82E16827106270
TV Capture Card$114.00pcHDTV PCHD-5500www.pchdtv.com/
Transceiver$55.00 USB  UIRTwww.usbuirt.com/order.htm
Orbiter$149.00Fiire Chiefwww.fiire.com/fiire-chief.php
Sound CardIn MOBORealtek  ALC1200 - 8 Channels
Graphics cardIn MOBONVIDIA GeForce 8300
Heatsink$24.99 COOLER  MASTER RR-CCH-P912-GP 92mm Sleeve CPU Coolerwww.newegg.com/Product/Product.aspx?Item=N82E16835103041
Thermal  Compound$5.99Arctic Silver 5  Thermal Compound - OEMwww.newegg.com/Product/Product.aspx?Item=N82E16835100007
LinuxMCEFREE!!!Woooohooo!www.linuxmce.com/

  Total:  $797.92
Title: Re: Newbie with Installation from Scratch
Post by: colinjones on January 24, 2009, 01:02:04 am
1) You need the second NIC, add it to your list. Install it, even if you don't connect it to anything. For a newbie, this is not-negotiable!

2) Don't bother with AlphaBlending unless you don't mind annoying tearing in your video even when the menu's are not on screen. This is not a performance thing, so bigger graphics hardware will do nothing to fix this. UI2 Overlay is the best mode to pick. On that subject, in case you were wondering, an 8300 chipset is massive overkill! It will work fine with the new nVidia drivers, but don't feel you have to use something like that, you can go much smaller if you wish.

3) 2GB of RAM is oodles, you would easily get away with 1GB if you wanted.

4) Seriously, don't plan around putting your media on the core. You can, but it is far better to scale another one of your PCs or a NAS, separation is king here. My suggestion would be to use the internal core drive for storing recorded TV only.

5) Blu-Ray (and HDDVD) support in LMCE is extremely rudimentary at best - don't rely on it, not much can be done about this currently due to commercial entities screwing the life out of products like Linux via the USA's Digital Millenium Act

Generally, if your mobo, graphics chipset, audio chipset or network chipset are not specifically mentioned on the wiki or in the forums as working, the bare minimum you have to do to ensure they will work with LMCE is check that they have working drivers for Linux, either K/Ubuntu 0710 or kernel 2.6.22-14
Title: Re: Newbie with Installation from Scratch
Post by: b4rney on January 24, 2009, 01:24:21 am
Got to agree with colinjones about the NIC. I tried to run linuxmce with one nic and it took months for me to realise it was a mistake.

Looks like you're getting a challenge with that motherboard too. A lot of issues in the wiki.
Whatever mainboard you get install i386 over 64 bit. It's generally more stable.

Good luck with your first steps into linuxmce. Stick with the tested good hardware and have fun.
Barney
Title: Re: Newbie with Installation from Scratch
Post by: thedaver on January 24, 2009, 05:14:38 am
Quote from: b4rney on January 24, 2009, 01:24:21 am
Whatever mainboard you get install i386 over 64 bit. It's generally more stable.

Can you cite a reference or something on that 64 vs 32 bit decision?  Would appreciate understanding the risk/reward a bit better.
THANKS!
Title: Re: Newbie with Installation from Scratch
Post by: b4rney on January 24, 2009, 12:13:43 pm
Hi thedaver,
I think if you search the forums you'll find the general consensus is that 32bit has fewer issues and is more stable and that the benefits of 64bit are outweighed by this. This might change with the new version in development though.

I have two 64bit computers running 32bit linuxmce 710. It's rock solid ... so I recommend it!
Title: Re: Newbie with Installation from Scratch
Post by: colinjones on January 24, 2009, 12:26:32 pm
Reality is, 64bit is not a panacea - it only offers advantages for specific types of workload. Stuff that needs a very large virtual address space for mapping mega large processes - none of that going on in LMCE, and some types of heavy duty calculation are the main ones. I seriously doubt that there is much 64 bit maths going on in your average MPEG or H264 decompression, but I suppose there could be. Either way, it would seem that the improvement in performance for a media player would be very marginal at best, and there is a material (albeit somewhat anecdotal) disadvantage in stability.

If we were running huge databases in MySQL or mega-number crunchers, then yes....
Title: Re: Newbie with Installation from Scratch
Post by: Ray_N on January 25, 2009, 06:03:07 am
  Oh wow...this is excellent feedback. Thank you colin.
Now I'm kinda disappointed here. One of the main reasons for us to do this system is to watch BluRay movies. We don't really watch a whole lot of TV programming (months can go by without us even turning the TV on for cable), but we do like our Netflix.
  So...ok here we go:
- I'll get the other NIC...no argument there.
- The 8300 chipset is MOBO integrated, so selecting a different one because 8300 would be wasteful means selecting a different MOBO. I have no issue selecting a different one but would then appreciate knowing which NVIDIA would be the best to have without going overboard. The page in hardware here (wiki.linuxmce.org/index.php/Hardware) mentions "It is recommended to use one from a GeForce 6200 to a GeForce 8500". That's why I went with the 8300. Don't know if it matters, but obviously I prefer to be able to send 1080p whenever possible. If it's that important to go lower I could save about $20.00 right there, so that's good. So please advice what number should I go to.
- I'll drop to 1Gb RAM (saves me some money to buy the NIC)  ;)
- I'll drop the internal HD to say...160GB? (saves some more money there too)

   Now for the big question: How could I play BluRay? Should I (can I) just buy a separate stand-alone player and somehow connect it to LinuxMCE? And, still be able to keep one control over everything, so LinuxMCE controls everything? The video mentions connectivity to VHS, so I assume you could also connect a BluRay player. It'd be kinda strange to have two different drive bays there, but hey! you do what you need to do, right...
What say the gods?

Thank you,
Ray
Title: Re: Newbie with Installation from Scratch
Post by: tschak909 on January 25, 2009, 07:19:42 am
Currently, due to AACS protection issues, blu-ray ripping and playback is still very early in the game....

You can use other things to rip the image, and copy them over. MPlayer will then play them, but you will need the fastest dual core CPU that you can buy, as the codecs we use need lots of optimization.

You can also connect a blu-ray player and control it via say, IR, and have it be a legacy AV control. Later when we have device template for the Hauppauge HD-PVR, it could be used to digitize the component output so that it can be displayed on any media director in the house.

-Thom
Title: Re: Newbie with Installation from Scratch
Post by: colinjones on January 25, 2009, 11:42:55 pm
Separation is a philosophy - LMCE isn't a specialist in storage, backup, redundancy, etc. It can do it, but if you can place your (valuable) media on a device that is better suited for these characteristics rather than on your (non-valuable) LMCE device, then why not?

By "non-valuable", this is taken to mean that the LMCE core device does not contain any irreplaceable data. At best it is stateful only - so a little config to get back to where you were, and even that is reducing with some of jon's work. So if your core was to fall over in a screaming heap, your first reaction would not be "oh shit I have to spend 40 mins rebuilding my core" it will be "shit f*#@! d#@$%, arrgh all the media I have been building up over the last 10 years is lost for ever!" See the difference?

On occasion you will likely need to rebuild your core, and so not having media on it vastly simplifies and speeds this process - you just stick a DVD in, hit the reset button and you are on your way. With media on there you may spend hours getting it all off first for safety, and much longer when you suddenly relise that you haven't got enough storage elsewhere to keep it!

Realistically, a simple NAS device consumes only a fraction more power than a hard drive on its own - do you really not have another PC in the house? Either way, you have more flexibility in setting up and scaling up or out your storage, redundancy and backup architecture when using NAS(s) or other equivalent, dedicated technologies. When you reach the limit inside a PC (like LMCE) it starts to become inconvenient, awkward, expensive or impossible to scale up. You can easily buy NAS's that allow you to add lots of drives, or daisy chain, or simply plonk another standalone NAS on your network as an additional share... no limits. Also, hardware independence - get a second cheap NAS, and use software to mirror between them. No amount of RAID will save you from a fire, but this potentially could (either in a NAS or an actual house fire!)
Title: Re: Newbie with Installation from Scratch
Post by: Ray_N on January 26, 2009, 05:16:10 am
Excellent!
   This is great...thanks guys.
Thom:  Thank you for that insight into ripping BluRay, I think that will work. Rip somewhere else and then LinuxMCE will play the BluRay .iso file.
   So here's my "final" shopping list. I added the NIC, lowered the memory and HD capacity and even changed to a nicer case with the money saved. What do you guys think? Any showstoppers? Comments are welcome...

Thanks,
Ray
Item
Cost
Description
Website
Case$58.99 hec Black 0.7mm Thickness SECC Steel 7KJ9 Micro ATX Media Center / HTPC Case - Retailwww.newegg.com/Product/Product.aspx?Item=N82E16811121068
CPU$78.00 AMD
  Athlon 64 X2 7750 Kuma 2.7GHz 2 x 512KB L2 Cache 2MB L3 Cache Socket AM2+ 95W  Dual-Core black edition		www.newegg.com/Product/Product.aspx?Item=N82E16819103300
Motherboard$89.99ASUS M3N78-EM  AM2+/AM2 NVIDIA GeForce 8300 HDMI Micro ATX AMD www.newegg.com/Product/Product.aspx?Item=N82E16813131354
RAM$22.99 Kingston HyperX 1GB 240-Pin DDR2 SDRAM DDR2 1066 (PC2 8500) Dual Channel Kit Desktop Memorywww.newegg.com/Product/Product.aspx?Item=N82E16820104012
Hard Drive$34.99Western Digital Caviar Blue WD800JD 80GB 7200 RPM 8MB Cache SATA 3.0Gb/s Hard Drive - OEMwww.newegg.com/Product/Product.aspx?Item=N82E16822135106
BluRay Player$109.99 LITE-ON  Black 6X Blu-ray DVD-ROM 16X DVD-ROM 48X CD-ROM SATA Internal 6X Blu-Ray DVD  ROM & 16X DVD±R DVD Burner Model iHES106-29 - OEMwww.newegg.com/Product/Product.aspx?Item=N82E16827106270
TV Capture Card$114.00pcHDTV PCHD-5500www.pchdtv.com/
2nd NIC$27.49Intel PWLA8391GT 10/ 100/ 1000Mbps PCI PRO/1000 GT Desktop Adapter 1 x RJ45 - OEMwww.newegg.com/Product/Product.aspx?Item=N82E16833106121
Transceiver$55.00 USB  UIRTwww.usbuirt.com/order.htm
Orbiter$149.00Fiire Chiefwww.fiire.com/fiire-chief.php
Sound CardIn MoBoRealtek  ALC1200 - 8 Channels
Graphics cardIn MoBoNVIDIA GeForce 8300
CPU Cooler$24.99 COOLER MASTER RR-CCH-P912-GP 92mm Sleeve CPU Coolerwww.newegg.com/Product/Product.aspx?Item=N82E16835103041
Thermal  Compound$5.99Arctic Silver 5  Thermal Compound - OEMwww.newegg.com/Product/Product.aspx?Item=N82E16835100007
LinuxMCEFREE!!!Woooohooo!www.linuxmce.com/

  Total:  $771.42
Title: Re: Newbie with Installation from Scratch
Post by: tkmedia on January 26, 2009, 05:20:54 am
Take a closer look at that mother board some others have had problems with that mobo working oob with LinuxMCE 0710

chk post

http://forum.linuxmce.org/index.php?topic=6838.0


Tim
Title: Re: Newbie with Installation from Scratch
Post by: tkmedia on January 26, 2009, 05:27:27 am
Note: due to limited quantities the Fiire Chief is presently only offered for sale along with a Fiire Engine (Fiire 12TB) or a Fiire Station (Prestige, Prestige Light, or Invisible).


You may want to look at other options for orbiters n800, cisco, 7970, WebDt366


good luck

Tim
Title: Re: Newbie with Installation from Scratch
Post by: colinjones on January 26, 2009, 07:15:20 am
or perhaps a Gyration remote
Title: Re: Newbie with Installation from Scratch
Post by: Marie.O on January 26, 2009, 05:09:57 pm
Instead of looking at a single NAS with more drives, how about adding a second NAS?
Title: Re: Newbie with Installation from Scratch
Post by: tkmedia on January 26, 2009, 05:18:04 pm
I put together a freenas box combined with the 4bay 3 ware side car for raid5 3tb been up for about week now.


So far very happy with it.




Tim
Title: Re: Newbie with Installation from Scratch
Post by: Ray_N on January 26, 2009, 08:36:26 pm
Well that's just great...  >:(
   I don't think I want to buy 100 Fiire Chiefs just so I could use one. Thank you for the heads-up Tim. I did look at the Gyration remotes but I just don't like that awful Windows logo right in the middle...It would be kind of insulting to have all this nice Linux thing going and have to look at that stooopid logo every day. Any ideas? I actually called Gyration and asked them if they would manufacture now or in the future the exact same remote but without the Windoze logo. Their answer: "Hell no...We won't go...", and he referred me to a company called Fiire. How about that?  So I asked him about manufacturing a remote that (just like some ladies watches and cellphones) you could open the clear plastic flip cap where the logo is and put in any picture that you wanted. He said No to that also.
   But he did say that I could, myself open up the remote and change the logo...but did clarify that that would void the warranty...How about that now?

   In terms of the MoBo, I think I'm getting confused by the numbers here:
- M3N78-EMH HDMI: This one seems to be the one that Tim mentions is having huge issues
   (www.asus.com/products.aspx?l1=3&l2=149&l3=643&l4=0&model=2082&modelmenu=1)

- M3N78-EM: Seems to have worked to some people with minor tweaking (http://wiki.linuxmce.org/index.php/ASUS_M3N78-EM)
   (www.asus.com/products.aspx?l1=3&l2=149&l3=676&l4=0&model=2319&modelmenu=1)

Is this not true? And so based on http://wiki.linuxmce.org/index.php/ASUS_M3N78-EM , I should not have that many problems. Especially when 0810 comes out. Am I missing something?
Thanks,
R
Title: Re: Newbie with Installation from Scratch
Post by: seth on January 26, 2009, 08:56:35 pm
 ;)
@Domodude

Just build  small form factor pc, with hardware you have laying around, or really inexpensive mobo/cpu combos, get a 3com or highly available/inexpensive NIC card, put some controllers in for extra storage (scale as you need) and run FreeNAS.

Going to be cheaper, and then you will not be limited as to the number/size of the drives you decide to use/add.


Regards,

Seth
Title: Re: Newbie with Installation from Scratch
Post by: tkmedia on January 26, 2009, 09:02:01 pm
If you call minor tweaking building your own nic driver and replacing on board video cards go for it.

If not you may want a 6x or 7x mobo so it will work out of the box. especially for 0710


good luck


Tim
Title: Re: Newbie with Installation from Scratch
Post by: colinjones on January 26, 2009, 10:31:18 pm
Quote from: Domodude on January 26, 2009, 07:51:24 pm
Quote from: posde on January 26, 2009, 05:09:57 pm
Instead of looking at a single NAS with more drives, how about adding a second NAS?

That's always a possibility but I would like to concentrate everything in one box. My aim is to have a 3 or 4 TB RAID5, with a spare drive already installed. There should also be room for expansion, because 3TB will soon turn out to be too little (no matter how big your drive is....). So that requires at least 3x1(3GB)+1(RAID5)+1(spare)=5 drives.

All those larger RAID solutions are ridiculously expensive! Maybe just an old PC with a lot of bays? How much CPU would you need for, lets say, a box with eventually 6TB RAID5 storage plus a spare drive?


Is your aim to have highly reliable disk? Because your design is already "wasting" 2 disks and not achieving it for that level of wastage. If you are that keen to get reliability that you are prepared to waste one disk on parity and another for hotspare, then you definitely shouldn't be using RAID5. Not only is it nowhere near as reliable as most people incorrectly think, it can be less recoverable because of the striping in a loss of array config scenario. It is also vastly slower that any other RAID type (both read and write, and particularly for random access). No serious enterprise uses RAID5 any more, it was always just a compromise to reduce cost by "wasting" the minimum amount of disks. Typically RAID 10 or RAID 01 or meta RAIDs are used.

You could set up 4 x 2TB disks in a mirror set - this would give you 4TB storage, with less disks probably for a similar price. But you would have high performance both during normal operation and during degraded operation without the need for a hot spare. Plus, even if the RAID completely collapses in a disaster, all the data is on both pairs of disks in a form that can be read by a non-RAID system, making it far more recoverable.
Title: Re: Newbie with Installation from Scratch
Post by: Ray_N on January 27, 2009, 12:42:52 am
Ok...so all these conversations about the MoBo made me look for possible alternatives. I found this one.
ASUS M2N68-AM AM2+/AM2 NVIDIA GeForce 7050PV Micro ATX AMD Motherboardhttp://www.newegg.com/Product/Product.aspx?Item=N82E16813131342

Everything seems to be the exact same that the one I originally picked except for a lower nVidia chipset: NVIDIA GeForce 7050PV
and the Audio Chipset:    VIA VT1708B

I searched on the wiki and forums for comments on the audio but found not one comment. So I'm kind of worried on this one.

What do you say guys?...any good/bad experiences with this audio or MoBo?
Thank you,
R
Title: Re: Newbie with Installation from Scratch
Post by: tkmedia on January 27, 2009, 01:09:46 am
I am currently testing that board for use in my starter kits.

http://forum.linuxmce.org/index.php?topic=7266.0

I have been using a similar board from ABIT ANM2HD (7050) for over a year


The Asus M2N68Vm worked plug and play oob as MD I will be testing as a core this week.
only tested with analog sound .

I will test hdmi sound
and digital out hopefully this week as well



Tim

Title: Re: Newbie with Installation from Scratch
Post by: tkmedia on January 27, 2009, 02:29:57 am
Looks like some audio issues

I will test this week to see if i have the same issue.

http://forum.linuxmce.org/index.php?topic=7282.0;topicseen


Tim
Title: Re: Newbie with Installation from Scratch
Post by: tkmedia on January 27, 2009, 04:08:38 pm
Ok first test are in on the M2N68 -VM

0710 Testing:
i386- AMD64

Video: PV7050 tested fine at 720p OOB vga/hdmi
Audio: analog works OOB
Audio: HDMI not working OOB
Nic: PXE booted fine OOB
SPDIF: not tested yet - others have seen issues


Notes:
IEC958 not displayed in alsamixer


ToDo:
1080p video testing
Spdif testing
Test as core / hybrid


Tim



Tim
Title: Re: Newbie with Installation from Scratch
Post by: Zaerc on January 28, 2009, 01:12:19 am
Quote from: tkmedia on January 27, 2009, 04:08:38 pm
Ok first test are in on the M2N68 -VM

0710 Testing:
i386- AMD64

Video: PV7050 tested fine at 720p OOB vga/hdmi
Audio: analog works OOB
Audio: HDMI not working OOB
Nic: PXE booted fine OOB
SPDIF: not tested yet - others have seen issues


Notes:
IEC958 not displayed in alsamixer


ToDo:
1080p video testing
Spdif testing
Test as core / hybrid


Tim



Tim
Add it to the wiki.
Title: Re: Newbie with Installation from Scratch
Post by: indulis on January 28, 2009, 04:47:26 am
Quote from: colinjones on January 26, 2009, 10:31:18 pm

Is your aim to have highly reliable disk? Because your design is already "wasting" 2 disks and not achieving it for that level of wastage. If you are that keen to get reliability that you are prepared to waste one disk on parity and another for hotspare, then you definitely shouldn't be using RAID5. Not only is it nowhere near as reliable as most people incorrectly think, it can be less recoverable because of the striping in a loss of array config scenario. It is also vastly slower that any other RAID type (both read and write, and particularly for random access). No serious enterprise uses RAID5 any more, it was always just a compromise to reduce cost by "wasting" the minimum amount of disks. Typically RAID 10 or RAID 01 or meta RAIDs are used.

Actually most large organisations are using RAID5/6 for most data as it performs nearly as well as RAID-10 in transactional random I.O in most cases and you get a lot more capacity for your $.  The exception is where there is a very high write ratio.  Most modern disk subsystems will mask any RAID5 write penalty in the disk controller cache.

One of my customers actually did the test with a disk subsystem and 64 x 15K rpm drives, set up in either RAID5 or RAID-10, and the "crossover" point where RAID-10 got faster than RAID5 was 50% R/W ratio.  Higher write than that the RAID10 was better, less than that RAID5 was better.  This was for random I/O workload.

This might be different using a server set up to do RAID in software, or RAID cards (either fakeRAID or real RAID).  YMMV and I have not researched this to get any real numbers.

A bigger concern is data scrubbing which must be continually carried out checking all the drives for soft or hard errors before a total drive failure in a RAID array.  If this isn't done then the odds of hitting a hard read error during RAID rebuild are quite high.  This holds for both RAID-10 and RAID5.  Of course if you have a RAID5 array with a large # of disks you make the odds higher as you have to rely on ALL the other disks in the array being 100% OK.  With RAID-10 you only have to rely on one other disk being OK.
Title: Re: Newbie with Installation from Scratch
Post by: colinjones on January 28, 2009, 05:29:05 am
I'm sorry, Indulis, I simply do not agree. For the last 8 years I worked for a large multinational - as the Infrastructure Operations manager. I was intimately involved in the design, specification, purchasing and project implementations of numerous SAN, DAS, NAS, iSCSI, archival platforms and ultimately made the decisions on what approach to take. I made these decisions in light of years of experience with storage systems and in conjunction with Professional Services project advice from vendors such as EMC and IBM. On several occasions they even modelled performance of various suggested configurations.

In point of fact, on high end systems like SANs, the actual containers are so far abstracted from the RAID subsystems through meta- and hyper-LUNs, as almost to make no difference. Nevertheless, in the last 5 years, across hundreds of LUNs, many hundreds of servers, and several data centres, I recall only once implementing a RAID5 array, and that was a compromise at the time (which of course have a tendancy to stick and come back to haunt you!)

Notwithstanding that, asking such a vendor to implement a RAID 5 array is invariably met with strange looks, and ardent advice to the contrary. In my interface with peers in other medium and large enterprises with which this organisation operated, none ever considered RAID 5 to be an "enterprise" solution. In fact I have to go back 12 years, to my days as a small solutions provider to offices and retail establishments of 10 people or less and a single "server" plus dialup modem, before I can recall regularly using RAID 5.

Saying that RAID controller caches mask write penalties is a profound misunderstanding. It is simply wrong. Caches always run at 100%, therefore it merely shifts the problem... and that is circular... you don't get something for nothing.

Bringing this to the point of LMCE. Performance between different RAID technologies varies dramatically depending on what you are doing, as you pointed out. For instance, random writes on RAID10 are quiet poor compared with other technologies (such as RAID5). However, in pretty much every other test, RAID10 is far superior to RAID5. And in particular, sequential reads are vastly faster - note the vast majority of what LMCE does is sequential reads. Note that with RAID10 (and equivalents), adding spindles progressively and nearly linearly improves performance for most operations. In RAID5, write operations in particular get slower and slower as the subsystem has to read more stripes from more disks to calculate parity before writing it. This in turn causes blocking I/Os within the disk subsystem. Advanced systems can offload some of this to an extent, but never completely.

Transactional read performance is almost irrelevant - this is where "caching" does come in. In every database technology you can name, the db engine sets up a read-through buffer in core, and typcially has very sophisticated replacement algorithms. eg in MS SQL and particularly MS Exchange, the bulk of reads need to come from this buffer for the system to perform acceptable - this is particularly true of Exchange, which commonly achieves 70-90% buffer hits. This demonstrates where a disk cache becomes pointless - the buffer is usually so much larger than the disk cache and dedicated, that if it didn't hit the buffer, then it certainly isn't going to hit the disk cache! This is usually even true of high end Clariion and Symetrix SANs which have disk caches of at least 8-16GB (not MB!)
Title: Re: Newbie with Installation from Scratch
Post by: tschak909 on January 28, 2009, 07:07:46 am
Thank you for nailing that on the button. If _I_ had said it, he would probably be barking back at me.

-Thom
Title: Re: Newbie with Installation from Scratch
Post by: colinjones on January 28, 2009, 07:47:20 am
Taking a look at http://en.wikipedia.org/wiki/Standard_RAID_levels#RAID_5 is instructive, particularly the section on RAID5 performance. It doesn't completely enumerate the issue with read-modify-write, although I have read detailed technical breakdowns elsewhere, but it does give a feel for it. Essentially, say you wanted to increment a counter in a database, the steps you would need to take are:

Read that entry from disk
Increment it in memory
Write the entry back to disk (atomic transaction)
   Sequential write to transaction log
      Read all data blocks plus parity block in that stripe
      Calculate new parity block value once transaction entry is written
      Write transaction log entry
      Write new parity block
   Random write to database
      Read all data blocks plus parity block in that stripe
      Calculate new parity block value once db entry is updated
      Write db entry
      Write new parity block
End process

If this was on an 6 disk RAID5, it would correlate to 17 soft I/O operations to the disk surface. A similar RAID10 would correlate to 5 such operations, moreover, the number increases which each disk added to a RAID5, it remains the same when increasing a RAID10.

Also, note the article compares with RAID0 - which for read purposes is the same or slower than RAID10 (because you can read multiple sequential or random pieces of data from multiple channels and disks simultaneously) - and it indicates that RAID5 is "slightly slower". For write performance in clearly indicates that it is dramatically slower (sometimes by as much as "an order of magnitude"). And mentions a group I had never heard of! BAARF - Battle Against Any RAID Five. An organisation I would have been a card carrying member of had they existed and I had been aware of them back in my DB days!! :)
Title: Re: Newbie with Installation from Scratch
Post by: nite_man on January 28, 2009, 09:04:28 am
I have Asus M3N78-EM (http://wiki.linuxmce.org/index.php/Asus_M3N78-EM) on my core/hybrid. So far I found following issues with it:

I didn't test RAID because I use NAS.
Title: Re: Newbie with Installation from Scratch
Post by: tschak909 on January 28, 2009, 05:17:00 pm
The storage radar will always automatically pick the NAS with the most storage space in the storage selector by default.

-Thom
Title: Re: Newbie with Installation from Scratch
Post by: colinjones on January 28, 2009, 10:00:56 pm
Quote from: Domodude on January 28, 2009, 02:04:01 pm
Hi,
Thanks for the very elaborate explanation. Looks like I will be revising my storage setup and ditch the RAID5.
If I do end up with several NAS units, is there any way to specify that music should go on NAS1, movies on NAS2, etc? Or expendable vs. valuable?

Quote from: colinjones on January 28, 2009, 07:47:20 am
And mentions a group I had never heard of! BAARF - Battle Against Any RAID Five. An organisation I would have been a card carrying member of had they existed and I had been aware of them back in my DB days!! :)
;D

Not sure I follow - music doesn't "go" anywhere as such. The only thing that "go"es somewhere in the sense you are talking about is when you record live TV as this the only time that LMCE writes something new. And Thom has answered that for you. Oh yeah, ripping DVDs/CDs, silly me - same thing, it will present you the options which you can then override if you wish...
Title: Re: Newbie with Installation from Scratch
Post by: colinjones on February 03, 2009, 09:19:06 pm
I'm assuming that the logic is just how Thom suggests, it will show the partition with the most space. I don't think you can set a default, certainly not by media type anyway. Really, its just going to present you with 2 or 3 location options in a menu with the largest at the top, so its a single click. You have to navigate to the subfolder you want the rip to be in anyway, so when ripping, allong with choosing which tracks, public/private, and giving it a name, saving on a single extra click will do nothing for ease or useability!
Title: Re: Newbie with Installation from Scratch
Post by: totallymaxed on February 03, 2009, 09:44:57 pm
Quote from: Ray_N on January 25, 2009, 06:03:07 am
- The 8300 chipset is MOBO integrated, so selecting a different one because 8300 would be wasteful means selecting a different MOBO. I have no issue selecting a different one but would then appreciate knowing which NVIDIA would be the best to have without going overboard. The page in hardware here (wiki.linuxmce.org/index.php/Hardware) mentions "It is recommended to use one from a GeForce 6200 to a GeForce 8500". That's why I went with the 8300. Don't know if it matters, but obviously I prefer to be able to send 1080p whenever possible. If it's that important to go lower I could save about $20.00 right there, so that's good. So please advice what number should I go to.
- I'll drop to 1Gb RAM (saves me some money to buy the NIC)  ;)
- I'll drop the internal HD to say...160GB? (saves some more money there too)

   Now for the big question: How could I play BluRay? Should I (can I) just buy a separate stand-alone player and somehow connect it to LinuxMCE? And, still be able to keep one control over everything, so LinuxMCE controls everything? The video mentions connectivity to VHS, so I assume you could also connect a BluRay player. It'd be kinda strange to have two different drive bays there, but hey! you do what you need to do, right...
What say the gods?

Thank you,
Ray


Hi Ray,

Colin is right in saying that currently there is not too much to be gained from using any nVidia card above say a 7300. But if you want to be able to exploit the forthcoming improvements in the nVidia driver and or use onboard chipset based nVidia graphics then really you should look at nVidia 8000 series cards or chipsets and above.

Re the external BlueRay player... yes this is possibly the best route to go currently. Something like the Denon 2500 or 3800 RS232 enabled BlueRay player routed through a Denon Surround Amp such as the 2309 would work well. Currently there are no device templates for the 2500/3800 players (we will be working on one or you could create one yourself). Even without the device template and RS232 control this would provide a very good BlueRay source (they are not cheap though!).

All the best

Andrew
Title: Re: Newbie with Installation from Scratch
Post by: Ray_N on February 03, 2009, 11:59:24 pm
Thanks for the insight Andrew, it does help. However, I just received all the parts shipment yesterday and started building the system already. On the BluRay, I decided to go the "rip somewhere else" route...'cause you're right on... those players aren't cheap.

Thank you...looking forward to contributing my successes/frustrations. :-)
R