[mythtv-users] OT: Troubleshooting write speed problems

[Nathan A. Smith]

On Mon, 2007-08-20 at 10:23 +0000, nasa01 at comcast.net wrote:
> Hi,
> 
> I know, this is way off topic, but I figured there must be a lot of smarter people on the list than I.
> I was troubleshooting what I thought was a network issue, when I decided to test my harddrive speeds... Looking at the results, my aim how changed.  How do I fix these write speed issues?  Info follows:
> 
>  I have three machines (Main, mythtv, MythTV_Server).  All machines are running a version of mandrake (later than 2006).  
> 
> mythtv:
> Kernel:  2.6.22-rc1
> 
> GIGABYTE GV-NX73G256D-RH GeForce 7300GS 512MB(256MB on Board) GDDR2 PCI Express x16 Video Card 
> WINTEC AMPO 1GB (2 x 512MB) 240-Pin DDR2 SDRAM DDR2 533 (PC2 4200) Dual Channel Kit Desktop Memory Model 3AMD2533-1G1K-R 
> AMD Athlon 64 X2 3800+(65W) Windsor 2.0GHz Socket AM2 Processor 
> Seagate ST3300831A ATA Drive
> MSI K9N Platinum Socket AM2 NVIDIA nForce 570 Ultra MCP ATX AMD Motherboard 
> 
> hdparm -v /dev/hda
> 
> multcount = 16(on)
> IO_Support = 1 (32-bit)
> unmaskirq = 1 (on)
> using_dma = 1 (on)
> keepsettings = 0 (off)
> readahead = 256 (on)
> geometry = 19457/255/63, sectors = 312581808, start = 0
> 
> dd results very similar to dd results for hda on MythTV_Server
Here are the actual results:

command: sync; time bash -c "dd if=/dev/zero bs=1024k count=2048
of=./test.tmp; sync"

Output:  2048+0 records in
         2048+0 records out
         2147483648 bytes (2.1 GB) copied, 134.439 seconds, 16 MB/s
         0.01user 20.47system 2:59.60elapsed 11%cpu (0avgtext+0avgdata
0maxresident)k
         0inputs+0outputs (4major+887minor)pagefaults 0swaps

> 
> *****************************************************************************************
> MythTV_Server:
> Kernel:  2.6.17-13mdv
> 
> HighPoint Technologies, RocketRaid 1740 
> DFI Infinity RS482 Motherboard 
> CPU AMD|A64 3400+ 2.2G 939 
> 756M generic ram 
> 4x320G Harddrives in Raid 5 
> 
> hdparm -v /dev/hda (same as mythtv, except for geometry)
> ...will update hdparm -v /dev/sda later (would this be usefull?)
> 
> hdparm -tT /dev/sda
> 
> /dev/sda:
>  Timing cached reads:   2432 MB in  2.00 seconds = 1214.37 MB/sec
>  Timing buffered disk reads:  184 MB in  3.01 seconds =  61.05 MB/sec
> 
This an ide drive in the server (loads the OS and setups up raid)
> time dd if=/dev/zero of=./test.tmp bs=1024k count=4000
> 2066+0 records in
> 2066+0 records out
> 2166358016 bytes (2.2 GB) copied, 129.33 seconds, 16.8 MB/s
> Command terminated by signal 2
> 0.02user 19.98system 2:09.49elapsed 15%CPU (0avgtext+0avgdata 0maxresident)k
> 0inputs+0outputs (1major+275minor)pagefaults 0swaps
> 
This is the actual raid...
> sync; time bash -c "dd if=/dev/zero bs=1024k count=2048 of=/mnt/Raid/testspeed; sync"
> 2048+0 records in
> 2048+0 records out
> 2147483648 bytes (2.1 GB) copied, 63.3346 seconds, 33.9 MB/s
> 0.01user 4.42system 1:13.53elapsed 6%CPU (0avgtext+0avgdata 0maxresident)k
> 0inputs+0outputs (4major+943minor)pagefaults 0swaps
> 
> 
> *******************************************************************************************
> 
> Main machine is an AMD 64 X2 3800+
> with a WD Raptor HD
> 
> 
> dd results for comparison....
> 
> 2048+0 records in
> 2048+0 records out
> 2147483648 bytes (2.1 GB) copied, 35.5994 seconds, 60.3 MB/S
> 
> 
> 
> Thanks,
> 
> Nasa
> 
> 
> 
> 
> 
> 
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