[plug] Raid 0 software? hardware?

[Adrian Woodley]

Biggest problem with hardware RAID is that if your controller blows up, 
you need to get an exact replacement to recover your array. With 
software RAID, all you need is a generic IDE controller, so when it dies 
you don't need and extact replacement.

Other advantages are that you can mix your hardware types - SATA, IDE, 
SCSI, USB, etc.

Have had great success with software RAID5 (3+1 disks) on a production 
machine. Still provides reasonable speed.

Gandalf:~# hdparm -t -T /dev/md1

/dev/md1:
 Timing cached reads:   1600 MB in  2.00 seconds = 799.32 MB/sec
 Timing buffered disk reads:   94 MB in  3.04 seconds =  30.94 MB/sec
Gandalf:~# hdparm -t -T /dev/hda

/dev/hda:
 Timing cached reads:   1592 MB in  2.00 seconds = 794.93 MB/sec
 Timing buffered disk reads:  150 MB in  3.00 seconds =  49.94 MB/sec
Gandalf:~# hdparm -t -T /dev/hdc

/dev/hdc:
 Timing cached reads:   1608 MB in  2.00 seconds = 803.72 MB/sec
 Timing buffered disk reads:  174 MB in  3.02 seconds =  57.61 MB/sec
Gandalf:~# hdparm -t -T /dev/hde

/dev/hde:
 Timing cached reads:   1588 MB in  2.00 seconds = 793.33 MB/sec
 Timing buffered disk reads:  126 MB in  3.06 seconds =  41.12 MB/sec
Gandalf:~# hdparm -t -T /dev/hdg

/dev/hdg:
 Timing cached reads:   1608 MB in  2.00 seconds = 802.92 MB/sec
 Timing buffered disk reads:  160 MB in  3.02 seconds =  52.94 MB/sec
Gandalf:~# uname -a
Linux Gandalf 2.6.10-ac10 #1 Tue Jan 25 14:19:44 WST 2005 i686 GNU/Linux
Gandalf:~# cat /proc/cpuinfo
processor       : 0
vendor_id       : AuthenticAMD
cpu family      : 6
model           : 10
model name      : AMD Athlon(tm) XP 2500+
stepping        : 0
cpu MHz         : 1829.888
cache size      : 512 KB
fdiv_bug        : no
hlt_bug         : no
f00f_bug        : no
coma_bug        : no
fpu             : yes
fpu_exception   : yes
cpuid level     : 1
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge 
mca cmov pat pse36 mmx fxsr sse pni syscall mmxext 3dnowext 3dnow
bogomips        : 3612.67

Regards,
Adrian

WolfBite wrote:

>pretty disappointed with my speeds using ITE8212
>hdparm 49->60
>Havent tested speeds with software raid yet.
>
>I would like some feed back on success/failure of
>raid.
>
>Anyone using a decent raid controller (hopefully
>doesnt cost alot :) with decent results?
>that is HOPEFULLY reckonized by the kernel (the hoops
>I have to go through for each raid controller has been
>a pain)
>
>the ite8212 is onboard (gigabyte raid)
>even got an old adaptec 1200a
>
>I would like some DECENT speed increase.
>
>Anyone?
>
>WolfBite
>
>
>		
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