I set up a Software RAID System previously. It contains four 120Gb harddrives, 8 partitions on each, with the forth drive being used as a spare:
Personalities : [raid1] [raid5]
read_ahead 1024 sectors
md1 : active raid1 hdc1[1] hda1[0]
15488 blocks [2/2] [UU]
md5 : active raid5 hdg5[3] hde5[2] hdc5[1] hda5[0]
249728 blocks level 5, 4k chunk, algorithm 0 [3/3] [UUU]
md6 : active raid5 hdg6[3] hde6[2] hdc6[1] hda6[0]
3999488 blocks level 5, 32k chunk, algorithm 0 [3/3] [UUU]
md7 : active raid5 hdg7[3] hde7[2] hdc7[1] hda7[0]
8000256 blocks level 5, 32k chunk, algorithm 0 [3/3] [UUU]
md8 : active raid5 hdg8[3] hde8[2] hdc8[1] hda8[0]
999680 blocks level 5, 32k chunk, algorithm 0 [3/3] [UUU]
md9 : active raid5 hdg9[3] hde9[2] hdc9[1] hda9[0]
224340224 blocks level 5, 32k chunk, algorithm 0 [3/3] [UUU]
md10 : active raid5 hdg10[3] hde10[2] hdc10[1] hda10[0]
1999616 blocks level 5, 32k chunk, algorithm 0 [3/3] [UUU]
unused devices: <none>
As you can see, the first is a simple RAID 1, all the others are
RAID 5. All have a chunk size of 32 and an ext3 filesystem (-b 4096
-R stride=8). Only md5 has a chunks size of 4 and an ext3 filesystem
with blocksize 1k and stride=4 (because it is so small).
Now, if I use bonnie++ on a dual 2GHz with 2Gb RAM on a reiserfs
partition on a 120Gb Maxtor IDE harddrive, I get the following
results:
Version 1.03 ------Sequential Output------ --Sequential Input- --Random-
-Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP /sec %CP
diamond 4G 14482 97 28019 18 17245 9 14144 90 37177 14 145.8 0
------Sequential Create------ --------Random Create--------
-Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
files /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP
16 410 13 +++++ +++ 381 11 436 13 +++++ +++ 283 9
If I use the same options on aforementioned RAID system (1GHz single
processor machine, 1Gb RAM and ext3), I get these results:
Version 1.03 ------Sequential Output------ --Sequential Input- --Random-
-Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP /sec %CP
ailab 2G 3229 22 3765 10 2335 26 4632 76 6126 65 150.6 1
------Sequential Create------ --------Random Create--------
-Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
files /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP
16 42 1 +++++ +++ 47 0 42 1 +++++ +++ 41 2
Eyeballing, there is a factor 4-8 of a difference. This can't be
mere processor power, can it? Does this mean that my RAID is
performing worse than crap?
Does anyone have any clues, any suggestions for a better test, or
any improvements for my RAID system? Russell?
Thanks,
--
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.''`. martin f. krafft <[EMAIL PROTECTED]>
: :' : proud Debian developer, admin, and user
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