I've just built 2 Atom based servers for home purpose (home backup of my websites and for entertainment)
CPUs are Dual core Atom @1.80 GHz
MainBoards are Gigabyte GA-D525TUD
First server: 2*2TB HD in raid 1 software:
[root@host674 ~]# hdparm -tT /dev/md0
/dev/md0:
Timing cached reads: 2432 MB in 2.00 seconds = 1215.88 MB/sec
Timing buffered disk reads: 10 MB in 3.19 seconds = 3.14 MB/sec
Uptime (not during hdparm):
top - 19:42:55 up 57 min, 1 user, load average: 3.28, 3.22, 3.10
Tasks: 109 total, 4 running, 105 sleeping, 0 stopped, 0 zombie
Cpu(s): 0.1%us, 2.0%sy, 0.0%ni, 90.1%id, 0.0%wa, 0.1%hi, 7.7%si, 0.0%st
Mem: 2049144k total, 238116k used, 1811028k free, 1788k buffers
Swap: 4072456k total, 0k used, 4072456k free, 129428k cached
Second server: 4*2TB HD in raid 6 software:
[root@host583 ~]# hdparm -tT /dev/md0
/dev/md0:
Timing cached reads: 2432 MB in 2.00 seconds = 1216.48 MB/sec
Timing buffered disk reads: 12 MB in 3.13 seconds = 3.83 MB/sec
Uptime (not during hdparm):
top - 15:27:13 up 58 min, 1 user, load average: 2.21, 2.29, 2.31
Tasks: 109 total, 2 running, 107 sleeping, 0 stopped, 0 zombie
Cpu(s): 0.1%us, 7.2%sy, 0.0%ni, 85.5%id, 0.0%wa, 0.2%hi, 7.1%si, 0.0%st
Mem: 2049144k total, 242588k used, 1806556k free, 2564k buffers
Swap: 3976044k total, 0k used, 3976044k free, 131912k cached
On both servers, hard disk access is something like this:
hdparm -t /dev/hda
/dev/hda:
Timing buffered disk reads: 2 MB in 3.96 seconds = 517.08 kB/sec
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Why is load average greater than 3 if cpus are 90% idle? It's fault of the hard disk, right? But why are hard disk such slow if the should be supposing to be doing anything?
Is the atom system the bottleneck?
Is the bottleneck something else?
Should i buy a PCI raid hardware card? (i don't have PCI-X, only PCI on the gigabyte motherboard)
If so, any suggestion?
My goal would be to reach 100MB/s on read.
Thank you a lot!
cat /proc/mdstat
, please....