Difference between revisions of "User talk:Mrsdonovan"
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I completely disagree with your notion that RAID 5 isn't acceptable. I routinely get 110MB/sec reads and 60MB/sec writes. Copying a file on the same volume is usually in the 45MB/sec range. You don't really say what your hardware is, but I'm doing this with (4) SATA drives and 256MB of RAM cache. Small burst writes to the cache are 290MB/sec. I've recorded (2) SD and (2) HD simultaneously while watching one of those HD streams. Not a single stutter. Might want to check out the [[LVM_on_RAID]] page if you ever head back to RAID 5. --[[User:DirkGecko|DirkGecko]] 16:30, 13 February 2008 (UTC) | I completely disagree with your notion that RAID 5 isn't acceptable. I routinely get 110MB/sec reads and 60MB/sec writes. Copying a file on the same volume is usually in the 45MB/sec range. You don't really say what your hardware is, but I'm doing this with (4) SATA drives and 256MB of RAM cache. Small burst writes to the cache are 290MB/sec. I've recorded (2) SD and (2) HD simultaneously while watching one of those HD streams. Not a single stutter. Might want to check out the [[LVM_on_RAID]] page if you ever head back to RAID 5. --[[User:DirkGecko|DirkGecko]] 16:30, 13 February 2008 (UTC) | ||
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| + | Only 45Mb/s? Doesn't just one HD stream at 1080p use 15 to 25Mbps? Are you using a dedicated RAID 5 card? I was talking about the software solution that comes with Linux. | ||
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| + | My hardware was using a mixture of IDE and SATA drives, so that might have been it. It wasn't continuous stuttering that was the problem, it was an intermittent loss of packets during high loads whose only affect on playback was to skip a few seconds. The problem was really intermittent and seemed worse during transitions, i.e. when playback/commercial detection was ending, etc. It might be due to a bug in MythTV too, where database writes, etc. can cause interruption of writing to the disks. [[User:Mrsdonovan|TugBoat]] 17:22, 13 February 2008 (UTC) | ||
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Revision as of 17:22, 13 February 2008
I completely disagree with your notion that RAID 5 isn't acceptable. I routinely get 110MB/sec reads and 60MB/sec writes. Copying a file on the same volume is usually in the 45MB/sec range. You don't really say what your hardware is, but I'm doing this with (4) SATA drives and 256MB of RAM cache. Small burst writes to the cache are 290MB/sec. I've recorded (2) SD and (2) HD simultaneously while watching one of those HD streams. Not a single stutter. Might want to check out the LVM_on_RAID page if you ever head back to RAID 5. --DirkGecko 16:30, 13 February 2008 (UTC)
Only 45Mb/s? Doesn't just one HD stream at 1080p use 15 to 25Mbps? Are you using a dedicated RAID 5 card? I was talking about the software solution that comes with Linux.
My hardware was using a mixture of IDE and SATA drives, so that might have been it. It wasn't continuous stuttering that was the problem, it was an intermittent loss of packets during high loads whose only affect on playback was to skip a few seconds. The problem was really intermittent and seemed worse during transitions, i.e. when playback/commercial detection was ending, etc. It might be due to a bug in MythTV too, where database writes, etc. can cause interruption of writing to the disks. TugBoat 17:22, 13 February 2008 (UTC)
