Re: Software RAID-0 striping over Hardware RAID-5
From: Tim Moore <hidden>
Date: 2004-09-23 00:23:30
quoted
From what I have read, RAID0 will just go as fast as your slowest disk.
Almost 2X faster.
[16:52] abit: > cat /proc/mdstat
Personalities : [raid0] [raid1] [raid5]
read_ahead 1024 sectors
md0 : active raid0 sdb5[1] sda5[0]
4192768 blocks 32k chunks
md1 : active raid0 sdb6[1] sda6[0]
2425600 blocks 32k chunks
md2 : active raid0 sdb7[1] sda7[0]
12707200 blocks 16k chunks
md3 : active raid0 sdb8[1] sda8[0]
20113152 blocks 64k chunks
unused devices: <none>
102400+0 records in
102400+0 records out
: 10.72 19% 0:10.72 s 2.12 u 0.02 mapf 112 mipf 12
: dd if=/dev/sda5 of=/dev/null bs=4k count=100k
102400+0 records in
102400+0 records out
: 11.33 19% 0:11.33 s 2.18 u 0.06 mapf 112 mipf 12
: dd if=/dev/sdb5 of=/dev/null bs=4k count=100k
102400+0 records in
102400+0 records out
: 5.81 32% 0:05.81 s 1.81 u 0.07 mapf 112 mipf 12
: dd if=/dev/md0 of=/dev/null bs=4k count=100k
[17:20] abit:~ > echo "scale=2;102400*4*1024;((10.72+11.33)/2)/5.81" | bc -q
419430400
1.89