Re: LVM *was* Re: [mythtv-users] Highest number of simultaneous streams recorded?
On Fri, Oct 14, 2005 at 03:45:16PM -0500, Alex Brekken wrote: If one wanted redundancy only (is that RAID-0??) then I take it you would skip LVM entirely, correct? - IOW, are the 2 mutually exclusive or can you use LVM with RAID? The reason I ask is because I'm starting to put together some plans to build a master backend server (currently I have a frontend/backend combo) which will not only house myth and it's recordings, but also all of my music and pictures/videos of the kids. (the latter of which I would want the redundancy in case of a drive failure). Raid 0 is striping for performance but no redundancy. Any other raid level (2,3,4,5,10) does redundancy. LVM basically gives you virtual partitions on top of anything that's set as an LVM partition type via fdisk. Some people use LVM ontop of raid. Someone may do raid 5 for redunancy and use LVM on top to allow them to shrink and grow virtual partitions as they want to move space around for mount points, but still have redunancy (Since LVM doesn't do redundancy). The only thing like raid LVM does is striping - but you can't resize a striped LVM partion, so LVM striping and Raid 0 are somewhat alike. --Brandon ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
Re: LVM *was* Re: [mythtv-users] Highest number of simultaneous streams recorded?
Thanks Brandon, that makes sense. For a masterbackend server that will probably have at most 2 clients, I don't get the feeling that striping the drives is necessary from a performance standpoint. I'm still trying to decide how to tackle the redundancy/backup issue. I'm wondering if doing this via RAID is overkill Rather than introduce that complication maybe I should just manually back the drives up every so often. On 10/17/05, Brandon Beattie [EMAIL PROTECTED] wrote:On Fri, Oct 14, 2005 at 03:45:16PM -0500, Alex Brekken wrote: If one wanted redundancy only (is that RAID-0??) then I take it you would skip LVM entirely, correct? - IOW, are the 2 mutually exclusive or can you use LVM with RAID? The reason I ask is because I'm starting to put together some plans to build a master backend server (currently I have a frontend/backend combo) which will not only house myth and it's recordings, but also all of my music and pictures/videos of the kids. (the latter of which I would want the redundancy in case of a drive failure). Raid 0 is striping for performance but no redundancy.Any other raidlevel (2,3,4,5,10) does redundancy.LVM basically gives you virtualpartitions on top of anything that's set as an LVM partition type via fdisk.Some people use LVM ontop of raid.Someone may do raid 5 forredunancy and use LVM on top to allow them to shrink and grow virtualpartitions as they want to move space around for mount points, but still have redunancy (Since LVM doesn't do redundancy).The only thing likeraid LVM does is striping - but you can't resize a striped LVM partion,so LVM striping and Raid 0 are somewhat alike.--Brandon ___mythtv-users mailing listmythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
Re: LVM *was* Re: [mythtv-users] Highest number of simultaneous streams recorded?
Alex Brekken wrote: Thanks Brandon, that makes sense. For a masterbackend server that will probably have at most 2 clients, I don't get the feeling that striping the drives is necessary from a performance standpoint. I'm still trying to decide how to tackle the redundancy/backup issue. I'm wondering if doing this via RAID is overkill Rather than introduce that complication maybe I should just manually back the drives up every so often. I go the manual route. I export my DB to another filesystem regularly and DVD+/-R the things I have archived in Divx under MythVideo (3-4 files per disk) and I don't really care much if I were to lose my recordings because it is just TV and the only thing I save long term is shows for the kids which can always be rerecorded. Implementing redundancy, raid levels, etc. in Linux seem more hastle than their worth when I can just back up what is important and live with losing the rest. Kevin ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
Re: [mythtv-users] Highest number of simultaneous streams recorded?
Kevin Kuphal wrote: Joe Votour wrote: I've recorded three SD streams off of analog cable using a PVR-350 and a PVR-500, while watching a fourth (or sometimes one of the three). The CPU usage for the recording is very low because of the hardware MPEG-2 encoders in the capture cards. No loss in stream quality. The question that you ask is very vague, because you don't mention what capture hardware you have. An analog BT8x8 card is much more CPU intensive than a PVR-x50, for instance. I don't think that you can capture an HD stream (though I may be wrong on this). There are no HD capture cards that I'm aware of (the bandwidth for HD is insanely huge), and the set-top boxes that support Firewire output downsample the output (how far, I don't know). You can capture ATSC HD with an HD-3000 or an Air2PC card as well as firewire. Both are supported. I believe there are DVB cards for non-US HD capture as well. Any DVB card can capture HD, provided HD is available. This is irrespective of whether it is MPEG-2 HD or H.264. Rudy P.S. I'm curious when DVB-S2 cards will appear on the market. ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
AW: [mythtv-users] Highest number of simultaneous streams recorded?
I use 3 budget dvb cards with no problems recording 3 streams and watch ing one of them while recoding. I think also hd recording can be done with this cards, because the data is not decoded by the card and so hd is only a strem with a higher bitrate. -Ursprüngliche Nachricht- Von: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Im Auftrag von Graham TerMarsch Gesendet: Freitag, 14. Oktober 2005 07:33 An: Discussion about mythtv Betreff: Re: [mythtv-users] Highest number of simultaneous streams recorded? On Thursday 13 October 2005 4:14 pm, [EMAIL PROTECTED] wrote: What is the most number of streams anyone on the list has simultaneously recorded without problem? I assume recording 2 streams while watching a third has been done, but has it been done with no loss in quality, etc? How about 3 streams? HD + an analog stream? I'd like to get an idea of what my limitations and potentials are before I get too deep in my current project. I just dropped a PVR-150 into my MythTV machine here, to go along-side of the two PVR-250s that were in it already. Several times a week we've got all three of them recording, while -also- watching something that we'd previously recorded. Funnier yet, I -know- that my box is a bit underpowered; its a 1GHz Athlon, 640MB RAM, runs on a single 200GB WD driver on ATA-100, and uses an Nvidia Geforce4 MX 4000 board for the TV-Out. NOT the beefiest of boxes, but I (and my wife) have been quite happy with it. We did have a few ivtv driver related issues when I put the PVR-150 in it, but I'm hoping that ivtv-0.4.0 resolved the drop-outs we were getting (if not, I'm sure I'll be in the dog house again). Quality wise, all three boards are recording at the default MythTV settings; I can't remember going in and twiddling them when I installed the machine. If you're planning on recording multiple streams, do yourself the favour and get a board that does hardware MPEG encoding. CPU usage on this machine is ~5% when recording 1 stream. I haven't checked on it when we're recording 3 streams and watching a recording, but it hasn't choked on us yet. :) -- Graham TerMarsch ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
Re: [mythtv-users] Highest number of simultaneous streams recorded?
Master backend: Recoding 2xHD 1080i Playback 1xHD 1080i Slave backend: Recording 2xAnalog 480i Playback 1xAnalog 480i Remote frontend 1: Playback 1xHD 1080i Remote frontend 2: Playback 1xHD 1080i =8 total streams I've had all streams going flawlessly on multiple occasions with no loss of quality, jitters, pauses, crashes or gremlins of any kind. A typical HD 1080i broadcast, I believe, clocks in around 15 mbit/s. More if it contains multiple streams, but a HD3000 only records one stream at a time in Myth so that's irrelevant. Granted this is all going on through a gigabit lan, but a 100mbit lan should be more than enough bandwidth and possibly even your newer 54 mbit and greater wireless lans. For your average 7200 rpm drive that has sustained read and write rates of about 30 MBytes/s, multiple HD streams should barely be a flicker of activity for the drive. [EMAIL PROTECTED] wrote: My apologies if this has been asked and answered already, but I searched the archives and couldn't find the answer. What is the most number of streams anyone on the list has simultaneously recorded without problem? I assume recording 2 streams while watching a third has been done, but has it been done with no loss in quality, etc? How about 3 streams? HD + an analog stream? I'd like to get an idea of what my limitations and potentials are before I get too deep in my current project. --Andy ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
Re: [mythtv-users] Highest number of simultaneous streams recorded?
What is the most number of streams anyone on the list has simultaneously recorded without problem? I assume recording 2 streams while watching a third has been done, but has it been done with no loss in quality, etc? How about 3 streams? HD + an analog stream? I'd like to get an idea of what my limitations and potentials are before I get too deep in my current project. we have 2 pvr-500's and we regularily record 4 streams at once at an average bitrate of about 4500 without any loss of quality. we have actually been contemplating putting another 500 into the mix. the bitrates of the recordings on a pvr-500 are miniscule compared to the throughput of a modern drive, though latency could be an issue i guess with a large number of streams. i just tried it and we have now recorded 4 shows and watched all four on four different frontends simultaneously without the backend breaking a sweat. though, my roommates did look at me funny as i ran around the house turning on all the tvs. ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
Re: [mythtv-users] Highest number of simultaneous streams recorded?
On Thu, Oct 13, 2005 at 06:14:23PM -0500, [EMAIL PROTECTED] wrote: What is the most number of streams anyone on the list has simultaneously recorded without problem? I assume recording 2 streams while watching a third has been done, but has it been done with no loss in quality, etc? How about 3 streams? HD + an analog stream? I'd like to get an idea of what my limitations and potentials are before I get too deep in my current project. The current limitations on number of streams has to do with what hardware you choose to use. This includes tuner cards, hard drives, network cards, and CPU. I think it would still be rather easy to get 10+ streams recording and 4-5 being played back (1 local, 3-4 remote) before you see any problems. To do this you would need either hardware assisted analog encoders, or an HD tuner because they won't use more than 3% or so CPU. To reach a 10Rec 5Play number, you would want a good processor and memory, something 3.4Ghz or over would be fine -- If you're not going to watch video locally though, I bet you could do all this with 2Ghz or less. Disk usage is the next issue. Using raid 0, 5 or 10 would help in this areas you may be able to do 15 streams total with 2-3 striped drives I would bet. Networking will be the final issue. HD streams run up to just under 20Mb/s. As much as we wish to get 1Gb/s speeds all the time, expecting much over 400Mb/s constant is not always possible. Myth struggles to play video smoothly unless it feels like it has room to breath and almost no packet loss. Personally I've recorded 5 HD streams at once (3 pcHDTV HD-3000's and 2 pcHDTV HD-2000 tuners) and watched 1 at once. The load on the (backend) AMD 2500XP was about 10% (Viewing the single stream to a frontend, P4 3.0Ghz). I've recorded 4 full HD station feeds (One channel was broadcasting 43Mb/s of data so I recorded this stations feed 4 times and saved the entire feed as-is to disk) to a single drive. This was all done prior to Myth getting an internal memory buffer that now only write disk when it needed to, not every second. When this buffer was added, the overall throughput to disk went up 3x-5x times. However, if I peg a 6 disk setup with dd'ing /dev/zero to a file, I can interupt a single recording disk write and lose some data - Ths fix for this though is simply increasing the memory buffer in Myth for recording HD data. Right now the only limitation I see is how many PCI slots your computer has, how many firewire devices you can reach before hitting the max bandwidth for the motherboards firewire bus, and how much data you can push through a network client to remote frontends. Right about when you max these things out I think the CPU and system bus would be near maxed and that's the point where Myth would start to struggle. At this point, adding extra backends will let you scale on a new level, but I've never experimented in this area. --Brandon ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
Re: [mythtv-users] Highest number of simultaneous streams recorded?
On Friday 14 October 2005 02:56, Jake wrote: we have 2 pvr-500's and we regularily record 4 streams at once at an average bitrate of about 4500 without any loss of quality. we have actually been contemplating putting another 500 into the mix. the bitrates of the recordings on a pvr-500 are miniscule compared to the throughput of a modern drive, though latency could be an issue i guess with a large number of streams. i just tried it and we have now recorded 4 shows and watched all four on four different frontends simultaneously without the backend breaking a sweat. though, my roommates did look at me funny as i ran around the house turning on all the tvs. awesome, I've been thinking about getting a PVR-500, its good to know its working well. hopefully it will work with a couple DVB HD3000 cards as well. Question, my play is to use one tuner and the svideo/audio(from cablebox) as the two inputs to the 500, is this combination possible? Steve ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
Re: [mythtv-users] Highest number of simultaneous streams recorded?
On Friday 14 October 2005 10:16, Brandon Beattie wrote: The current limitations on number of streams has to do with what hardware you choose to use. This includes tuner cards, hard drives, network cards, and CPU. I think it would still be rather easy to get 10+ streams recording and 4-5 being played back (1 local, 3-4 remote) before you see any problems. To do this you would need either hardware assisted analog encoders, or an HD tuner because they won't use more than 3% or so CPU. To reach a 10Rec 5Play number, you would want a good processor and memory, something 3.4Ghz or over would be fine -- If you're not going to watch video locally though, I bet you could do all this with 2Ghz or less. Disk usage is the next issue. Using raid 0, 5 or 10 would help in this areas you may be able to do 15 streams total with 2-3 striped drives I would bet. Networking will be the final issue. HD streams run up to just under 20Mb/s. As much as we wish to get 1Gb/s speeds all the time, expecting much over 400Mb/s constant is not always possible. Myth struggles to play video smoothly unless it feels like it has room to breath and almost no packet loss. another option if you find yourself recording this much is to use LVM (logical volume manager). It would allow you to connect, say four 300gig drives and use them all as one AND stripe data across them (like RAID 0). Or you could use 3 striped and the 4th as a parity drive in case one dies. This would most definitely give you the drive speed required to not only record 4+ streams at once, but play back equally as many. Steve ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
Re: [mythtv-users] Highest number of simultaneous streams recorded?
Steve, is there any way to add an LVM on an up-and-running system, or must it be done during the OS install when partitioning the disk? (sorry, I don't mean to hijack this thread but I figured this would be a quick answer) Thanks!On 10/14/05, Steve Adeff [EMAIL PROTECTED] wrote: On Friday 14 October 2005 10:16, Brandon Beattie wrote: The current limitations on number of streams has to do with what hardware you choose to use.This includes tuner cards, hard drives, network cards, and CPU.I think it would still be rather easy to get 10+ streams recording and 4-5 being played back (1 local, 3-4 remote) before you see any problems.To do this you would need either hardware assisted analog encoders, or an HD tuner because they won't use more than 3% or so CPU.To reach a 10Rec 5Play number, you would want a good processor and memory, something 3.4Ghz or over would be fine -- If you're not going to watch video locally though, I bet you could do all this with 2Ghz or less.Disk usage is the next issue.Using raid 0, 5 or 10 would help in this areas you may be able to do 15 streams total with 2-3 striped drives I would bet.Networking will be the final issue.HD streams run up to just under 20Mb/s.As much as we wish to get 1Gb/s speeds all the time, expecting much over 400Mb/s constant is not always possible.Myth struggles to play video smoothly unless it feels like it has room to breath and almost no packet loss.another option if you find yourself recording this much is to use LVM (logicalvolume manager). It would allow you to connect, say four 300gig drives and use them all as one AND stripe data across them (like RAID 0). Or you coulduse 3 striped and the 4th as a parity drive in case one dies.This would most definitely give you the drive speed required to not only record 4+ streams at once, but play back equally as many.Steve___mythtv-users mailing listmythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
LVM *was* Re: [mythtv-users] Highest number of simultaneous streams recorded?
On Friday 14 October 2005 14:25, Alex Brekken wrote: Steve, is there any way to add an LVM on an up-and-running system, or must it be done during the OS install when partitioning the disk? (sorry, I don't mean to hijack this thread but I figured this would be a quick answer) Thanks! On 10/14/05, Steve Adeff [EMAIL PROTECTED] wrote: On Friday 14 October 2005 10:16, Brandon Beattie wrote: The current limitations on number of streams has to do with what hardware you choose to use. This includes tuner cards, hard drives, network cards, and CPU. I think it would still be rather easy to get 10+ streams recording and 4-5 being played back (1 local, 3-4 remote) before you see any problems. To do this you would need either hardware assisted analog encoders, or an HD tuner because they won't use more than 3% or so CPU. To reach a 10Rec 5Play number, you would want a good processor and memory, something 3.4Ghz or over would be fine -- If you're not going to watch video locally though, I bet you could do all this with 2Ghz or less. Disk usage is the next issue. Using raid 0, 5 or 10 would help in this areas you may be able to do 15 streams total with 2-3 striped drives I would bet. Networking will be the final issue. HD streams run up to just under 20Mb/s. As much as we wish to get 1Gb/s speeds all the time, expecting much over 400Mb/s constant is not always possible. Myth struggles to play video smoothly unless it feels like it has room to breath and almost no packet loss. another option if you find yourself recording this much is to use LVM (logical volume manager). It would allow you to connect, say four 300gig drives and use them all as one AND stripe data across them (like RAID 0). Or you could use 3 striped and the 4th as a parity drive in case one dies. This would most definitely give you the drive speed required to not only record 4+ streams at once, but play back equally as many. Steve from my understanding, yes it is, and properly set up you can also add and remove drives from an LVM at any point as well. I recently discovered LVM so I've yet to implement it, but I did a good amount of research and it seems to be quite easy now and I did not see anything that made me think I'd have to reinstall. Of course, I wouldn't use a LVM for your root partition, at least until you know what your doing... I'm just going to be using it for my storage drives. Steve ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
Re: LVM *was* Re: [mythtv-users] Highest number of simultaneous streams recorded?
On Fri, Oct 14, 2005 at 03:11:42PM -0400, Steve Adeff wrote: another option if you find yourself recording this much is to use LVM (logical volume manager). It would allow you to connect, say four 300gig drives and use them all as one AND stripe data across them (like RAID 0). Or you could use 3 striped and the 4th as a parity drive in case one dies. This would most definitely give you the drive speed required to not only record 4+ streams at once, but play back equally as many. Steve from my understanding, yes it is, and properly set up you can also add and remove drives from an LVM at any point as well. I recently discovered LVM so I've yet to implement it, but I did a good amount of research and it seems to be quite easy now and I did not see anything that made me think I'd have to reinstall. Of course, I wouldn't use a LVM for your root partition, at least until you know what your doing... I'm just going to be using it for my storage drives. Before you go running off let me give you a warning. Although LVM supports striping, adding/removing disks, shrinking and growing fs's, they do _not_ all work together. If you stripe you can't add/remove disks or change fs size. If you use xfs or jfs you can't shrink a fs. After using Raid 0, 1, 5, LVM on 6 disks with XFS, JFS, and Reiser I have settled with only LVM and ReiserFS (As much as I dislike Reiser for performance downsides with many gig files compared to xfs and jfs). In my experience, raid 5 is overkill for my desire to record TV shows. Anything I want safe I backup to another computer completely. In dealing with 6 drives I've found it very useful to shrink fs's at times, and since ReiserFS (Not Reiser 4) is the only fs that supports shrinking I use it. Striping would be nice, but adding/removing disks I've found to be a much better feature. I've also found seagate drives to run 10%-30% faster for reading and writing (reading and writing 100+ gig files) plus the 5yr warranty comes in nice, since of 9 drives I've had in the last 3 years, half the Maxtor 200GB drives have gone bad. ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
Re: LVM *was* Re: [mythtv-users] Highest number of simultaneous streams recorded?
On Friday 14 October 2005 16:13, Brandon Beattie wrote: Before you go running off let me give you a warning. Although LVM supports striping, adding/removing disks, shrinking and growing fs's, they do _not_ all work together. If you stripe you can't add/remove disks or change fs size. If you use xfs or jfs you can't shrink a fs. After using Raid 0, 1, 5, LVM on 6 disks with XFS, JFS, and Reiser I have settled with only LVM and ReiserFS (As much as I dislike Reiser for performance downsides with many gig files compared to xfs and jfs). In my experience, raid 5 is overkill for my desire to record TV shows. Anything I want safe I backup to another computer completely. In dealing with 6 drives I've found it very useful to shrink fs's at times, and since ReiserFS (Not Reiser 4) is the only fs that supports shrinking I use it. Striping would be nice, but adding/removing disks I've found to be a much better feature. I've also found seagate drives to run 10%-30% faster for reading and writing (reading and writing 100+ gig files) plus the 5yr warranty comes in nice, since of 9 drives I've had in the last 3 years, half the Maxtor 200GB drives have gone bad. Thanks for the info! I'll keep all that in mind. I might just stick with a RAID 0 for my recording drive and leave backup to the LVM or plain filesystem or something... I'm looking at getting WD's w/ 3yr warranty's. I've had very good luck with them (and seagate as well) and they're about $40 less for 320gb than the seagates, which I can live with, since in 3 years time I plan on having 1TB drives ;-) (or something much larger than my current drives). ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
Re: LVM *was* Re: [mythtv-users] Highest number of simultaneous streams recorded?
If one wanted redundancy only (is that RAID-0??) then I take it you would skip LVM entirely, correct? - IOW, are the 2 mutually exclusive or can you use LVM with RAID? The reason I ask is because I'm starting to put together some plans to build a master backend server (currently I have a frontend/backend combo) which will not only house myth and it's recordings, but also all of my music and pictures/videos of the kids. (the latter of which I would want the redundancy in case of a drive failure). On 10/14/05, Steve Adeff [EMAIL PROTECTED] wrote: On Friday 14 October 2005 16:13, Brandon Beattie wrote: Before you go running off let me give you a warning.Although LVM supports striping, adding/removing disks, shrinking and growing fs's, they do _not_ all work together.If you stripe you can't add/remove disks or change fs size.If you use xfs or jfs you can't shrink a fs.After using Raid 0, 1, 5, LVM on 6 disks with XFS, JFS, and Reiser I have settled with only LVM and ReiserFS (As much as I dislike Reiser for performance downsides with many gig files compared to xfs and jfs). In my experience, raid 5 is overkill for my desire to record TV shows. Anything I want safe I backup to another computer completely.In dealing with 6 drives I've found it very useful to shrink fs's at times, and since ReiserFS (Not Reiser 4) is the only fs that supports shrinking I use it.Striping would be nice, but adding/removing disks I've found to be a much better feature. I've also found seagate drives to run 10%-30% faster for reading and writing (reading and writing 100+ gig files) plus the 5yr warranty comes in nice, since of 9 drives I've had in the last 3 years, half the Maxtor 200GB drives have gone bad.Thanks for the info!I'll keep all that in mind. I might just stick with a RAID 0 for my recordingdrive and leave backup to the LVM or plain filesystem or something... I'm looking at getting WD's w/ 3yr warranty's. I've had very good luck withthem (and seagate as well) and they're about $40 less for 320gb than theseagates, which I can live with, since in 3 years time I plan on having 1TB drives ;-) (or something much larger than my current drives).___mythtv-users mailing listmythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
Re: LVM *was* Re: [mythtv-users] Highest number of simultaneous streams recorded?
On Fri, 2005-10-14 at 14:13 -0600, Brandon Beattie wrote: ng and writing 100+ gig files) plus the 5yr warranty comes in nice, since of 9 drives I've had in the last 3 years, half the Maxtor 200GB drives have gone bad. I just want to second this. I have had two 160GB Maxtor drives die within a month of purchase. Maxtor used to be a reliable brand when disks were smaller, but my experiences with their larger drives have been bad and I won't ever buy another one. Got shafted on a rebate to boot )-: --Greg ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
Re: LVM *was* Re: [mythtv-users] Highest number of simultaneous streams recorded?
On Friday 14 October 2005 16:45, Alex Brekken wrote: If one wanted redundancy only (is that RAID-0??) then I take it you would skip LVM entirely, correct? - IOW, are the 2 mutually exclusive or can you use LVM with RAID? The reason I ask is because I'm starting to put together some plans to build a master backend server (currently I have a frontend/backend combo) which will not only house myth and it's recordings, but also all of my music and pictures/videos of the kids. (the latter of which I would want the redundancy in case of a drive failure). I'm doing something similar, I already have a file server, I plan on having a seperate MythTV computer with its own recording drives, but I plan on doing xvid encodes to my file server. RAID 0 is striped, RAID 1 is mirroring. I want to basically have one large drive on the file server with some sort of parity backup in case I loose one of the drives. I'm hoping to do this with LVM and one drive for parity repair. Steve ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
[mythtv-users] Highest number of simultaneous streams recorded?
My apologies if this has been asked and answered already, but I searched the archives and couldn't find the answer. What is the most number of streams anyone on the list has simultaneously recorded without problem? I assume recording 2 streams while watching a third has been done, but has it been done with no loss in quality, etc? How about 3 streams? HD + an analog stream? I'd like to get an idea of what my limitations and potentials are before I get too deep in my current project. --Andy ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
Re: [mythtv-users] Highest number of simultaneous streams recorded?
I've recorded three SD streams off of analog cable using a PVR-350 and a PVR-500, while watching a fourth (or sometimes one of the three). The CPU usage for the recording is very low because of the hardware MPEG-2 encoders in the capture cards. No loss in stream quality. The question that you ask is very vague, because you don't mention what capture hardware you have. An analog BT8x8 card is much more CPU intensive than a PVR-x50, for instance. I don't think that you can capture an HD stream (though I may be wrong on this). There are no HD capture cards that I'm aware of (the bandwidth for HD is insanely huge), and the set-top boxes that support Firewire output downsample the output (how far, I don't know). -- Joe --- [EMAIL PROTECTED] wrote: My apologies if this has been asked and answered already, but I searched the archives and couldn't find the answer. What is the most number of streams anyone on the list has simultaneously recorded without problem? I assume recording 2 streams while watching a third has been done, but has it been done with no loss in quality, etc? How about 3 streams? HD + an analog stream? I'd like to get an idea of what my limitations and potentials are before I get too deep in my current project. --Andy ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users __ Yahoo! Mail - PC Magazine Editors' Choice 2005 http://mail.yahoo.com ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
Re: [mythtv-users] Highest number of simultaneous streams recorded?
On 10/13/05, Joe Votour [EMAIL PROTECTED] wrote: I've recorded three SD streams off of analog cableusing a PVR-350 and a PVR-500, while watching a fourth(or sometimes one of the three).The CPU usage forthe recording is very low because of the hardwareMPEG-2 encoders in the capture cards.No loss in stream quality.The question that you ask is very vague, because youdon't mention what capture hardware you have.Ananalog BT8x8 card is much more CPU intensive than aPVR-x50, for instance. I don't think that you can capture an HD stream(though I may be wrong on this).There are no HDcapture cards that I'm aware of (the bandwidth for HDis insanely huge), and the set-top boxes that supportFirewire output downsample the output (how far, I don't know).Joe[EMAIL PROTECTED] wrote: My apologies if this has been asked and answered already, but I searched the archives and couldn't find the answer. What is the most number of streams anyone on the list has simultaneously recorded without problem?I assume recording 2 streams while watching a third has been done, but has it been done with no loss in quality, etc? How about 3 streams?HD + an analog stream?I'd like to get an idea of what my limitations and potentials are before I get too deep in my current project. Andy I think what might be more of concern here is how much you can write to disk before your buffers overflow. -- Thanks,Devan Lippman devan at lippman dot net ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
RE: [mythtv-users] Highest number of simultaneous streams recorded?
Thanks for the input. Right now I have a BT8x8 card. I'm going to upgrade to a hauppauge pvr-500 some time soon, but right now I'm trying to learn with what I have. Is it better to go that route, or is it a whole other learning curve when I move to the hardware based encoder cards? I'm just getting started in all of this, so I'm afraid you all might have to tolerate a few poorly worded questions until I get my feet on firm ground. :) --Andy -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Joe Votour Sent: Thursday, October 13, 2005 6:50 PM To: Discussion about mythtv Subject: Re: [mythtv-users] Highest number of simultaneous streams recorded? I've recorded three SD streams off of analog cable using a PVR-350 and a PVR-500, while watching a fourth (or sometimes one of the three). The CPU usage for the recording is very low because of the hardware MPEG-2 encoders in the capture cards. No loss in stream quality. The question that you ask is very vague, because you don't mention what capture hardware you have. An analog BT8x8 card is much more CPU intensive than a PVR-x50, for instance. I don't think that you can capture an HD stream (though I may be wrong on this). There are no HD capture cards that I'm aware of (the bandwidth for HD is insanely huge), and the set-top boxes that support Firewire output downsample the output (how far, I don't know). -- Joe --- [EMAIL PROTECTED] wrote: My apologies if this has been asked and answered already, but I searched the archives and couldn't find the answer. What is the most number of streams anyone on the list has simultaneously recorded without problem? I assume recording 2 streams while watching a third has been done, but has it been done with no loss in quality, etc? How about 3 streams? HD + an analog stream? I'd like to get an idea of what my limitations and potentials are before I get too deep in my current project. --Andy ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users __ Yahoo! Mail - PC Magazine Editors' Choice 2005 http://mail.yahoo.com ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
Re: [mythtv-users] Highest number of simultaneous streams recorded?
What is the most number of streams anyone on the list has simultaneously recorded without problem? I assume recording 2 streams while watching a third has been done, but has it been done with no loss in quality, etc? How about 3 streams? HD + an analog stream? I'd like to get an idea of what my limitations and potentials are before I get too deep in my current project. It's going to depend on your disk I/O and the bitrate of your recorded streams. Look at the specs for your drive(s) and any raid controllers and then do the math based on the bitrate(s) you are capturing at. - Ben -- A: Because it destroys the flow of conversation. Q: Why is top posting dumb? ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
Re: [mythtv-users] Highest number of simultaneous streams recorded?
[EMAIL PROTECTED] wrote: What is the most number of streams anyone on the list has simultaneously recorded without problem? I assume recording 2 streams while watching a third has been done, but has it been done with no loss in quality, etc? How about 3 streams? Recorded 4 shows while watching one pre-recorded using 4xPVR-250's in a single combined FE/BE (that's also running all sorts of services--Samba, Apache, FTP, ...) with no loss of quality. HD + an analog stream? Don't yet have an HDTV setup in place. I'd like to get an idea of what my limitations and potentials are before I get too deep in my current project. Using Hauppauge PVR-x50's or HDTV capture cards takes virtually no CPU and even HDTV has a relatively low bitrate compared to UDMA-enabled hard drives, but if all else fails, just set up another backend... Mike ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
Re: [mythtv-users] Highest number of simultaneous streams recorded?
Joe Votour wrote: I've recorded three SD streams off of analog cable using a PVR-350 and a PVR-500, while watching a fourth (or sometimes one of the three). The CPU usage for the recording is very low because of the hardware MPEG-2 encoders in the capture cards. No loss in stream quality. The question that you ask is very vague, because you don't mention what capture hardware you have. An analog BT8x8 card is much more CPU intensive than a PVR-x50, for instance. I don't think that you can capture an HD stream (though I may be wrong on this). There are no HD capture cards that I'm aware of (the bandwidth for HD is insanely huge), and the set-top boxes that support Firewire output downsample the output (how far, I don't know). You can capture ATSC HD with an HD-3000 or an Air2PC card as well as firewire. Both are supported. I believe there are DVB cards for non-US HD capture as well. Kevin ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
Re: [mythtv-users] Highest number of simultaneous streams recorded?
On Thursday 13 October 2005 4:14 pm, [EMAIL PROTECTED] wrote: What is the most number of streams anyone on the list has simultaneously recorded without problem? I assume recording 2 streams while watching a third has been done, but has it been done with no loss in quality, etc? How about 3 streams? HD + an analog stream? I'd like to get an idea of what my limitations and potentials are before I get too deep in my current project. I just dropped a PVR-150 into my MythTV machine here, to go along-side of the two PVR-250s that were in it already. Several times a week we've got all three of them recording, while -also- watching something that we'd previously recorded. Funnier yet, I -know- that my box is a bit underpowered; its a 1GHz Athlon, 640MB RAM, runs on a single 200GB WD driver on ATA-100, and uses an Nvidia Geforce4 MX 4000 board for the TV-Out. NOT the beefiest of boxes, but I (and my wife) have been quite happy with it. We did have a few ivtv driver related issues when I put the PVR-150 in it, but I'm hoping that ivtv-0.4.0 resolved the drop-outs we were getting (if not, I'm sure I'll be in the dog house again). Quality wise, all three boards are recording at the default MythTV settings; I can't remember going in and twiddling them when I installed the machine. If you're planning on recording multiple streams, do yourself the favour and get a board that does hardware MPEG encoding. CPU usage on this machine is ~5% when recording 1 stream. I haven't checked on it when we're recording 3 streams and watching a recording, but it hasn't choked on us yet. :) -- Graham TerMarsch ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
