possible issues with Dell/Perc5 raid
Bill Moran
wmoran at collaborativefusion.com
Fri May 11 13:52:30 UTC 2007
In response to Randy Schultz <schulra at earlham.edu>:
> Hi there,
>
> We just purchased a Dell 860 with these specifics:
> - dual core pentium 915, 2.8 GHz, 800MHz FSB
> - 2x512 MB 533 MHz DDR2 RAM
> - Dell's SAS/SATA drive controller(which is actually an LSILogic)
> - their 5IR PCI-Express internal RAID controller
> - a pair of 250 GB SATA II's set up RAID 1
>
> After installing 6.2-RELEASE on the system I noticed, while pulling the ports
> collection off the CDROM, that the speed to the drives started out just fine
> but long before the ports collection was installed the transfer rate was down
> to ~35kB/s. Huh. So I started paying closer attention. I installed a couple
> of ports and every time there was anything but miniscule data being
> transferred to/from disk the transfer rate bottomed out. I installed the
> blogbench port and it confirmed the I/O as tremendously sluggish. I've
> attached the output of the blogbench runs. The first is from an old 700 MHz
> pc, Acer M25C mobo, with 1 IDE drive just for comparison. The second data set
> is the new Dell. I've also attached the output of dmesg. Everything looks
> fine except for the mpt lines. Would those be telling of something amiss or
> are they innocuous barks?
>
> I understand that RAID 1 is not the fastest but I certainly expected it to be
> faster than it is, esp. with hw RAID. Are my expectations too high and this
> is normal?
My personal server is a Dell 860 configured very similarly to yours,
with the difference that it has a single 160G SATA drive (no RAID).
It's also running 6.2.
Frequency = 10 secs
Scratch dir = [/home/wmoran/blogbench]
Spawning 3 writers...
Spawning 1 rewriters...
Spawning 5 commenters...
Spawning 100 readers...
Benchmarking for 30 iterations.
The test will run during 5 minutes.
Nb blogs R articles W articles R pictures W pictures R comments W comments
23 40257 1492 21472 1191 21093 4394
35 36694 723 24248 906 23669 3058
47 32632 702 23053 622 20938 2639
59 31514 755 22262 662 20536 2255
69 43012 865 30262 711 25146 3160
78 27864 620 20136 485 15956 2146
88 27356 699 19230 412 16104 1706
98 33987 757 23865 647 20387 2573
107 11491 388 7744 432 6358 1208
112 5086 320 3460 173 3193 716
116 3708 190 2437 210 2372 559
120 4654 360 3046 240 3375 910
123 1669 104 1120 89 1003 305
125 1913 135 1263 94 917 467
127 1843 130 1278 128 715 359
127 2328 201 1735 116 1113 368
130 2459 129 1612 103 1000 284
131 2465 76 1499 163 953 460
135 2374 184 1658 162 950 645
137 2412 163 1594 169 1152 585
140 1877 122 1254 137 773 506
144 1512 260 1091 91 628 576
144 1410 153 968 50 1345 430
145 1475 126 849 112 1127 363
148 1670 108 1101 84 874 247
150 2232 159 1536 96 1077 353
151 1269 74 850 90 866 278
154 1143 106 835 97 679 363
155 1407 169 1005 43 1075 397
157 1434 88 1082 101 822 326
Final score for writes: 157
Final score for reads : 6648
For comparison, here are the scores you posted:
Frequency = 10 secs
Scratch dir = [/var/tmp]
Spawning 3 writers...
Spawning 1 rewriters...
Spawning 5 commenters...
Spawning 100 readers...
Benchmarking for 30 iterations.
The test will run during 5 minutes.
Nb blogs R articles W articles R pictures W pictures R comments W comments
0 1505 101 0 16 0 181
0 2163 66 37 35 1940 142
0 1671 42 127 33 1304 109
1 2228 11 1008 84 2482 144
1 2027 34 1173 61 3059 145
1 1407 22 1291 32 628 70
3 3306 71 3330 39 1323 156
4 3080 91 3058 22 2152 149
4 1453 36 1306 16 596 64
5 3190 56 2595 50 1423 144
6 3299 50 2073 59 834 134
6 1625 23 978 33 488 68
6 2954 35 2032 73 1065 142
8 3157 36 2198 78 1307 140
9 1124 19 767 24 592 56
9 2837 45 2093 64 1442 142
11 2798 50 2124 63 1753 143
12 1395 30 1181 23 776 69
13 3312 87 2696 24 1283 143
13 3105 102 2517 12 1546 146
13 1670 43 1129 22 1266 80
14 2248 32 1594 63 1900 119
16 2876 78 2268 22 1608 136
16 1797 52 1244 16 1168 89
16 2142 48 1466 35 1649 106
17 2903 45 2123 58 1406 131
18 2096 22 1536 56 1096 97
19 2091 30 1310 44 1076 100
20 3152 41 2117 68 1127 138
21 2510 52 1578 34 1294 115
Final score for writes: 21
Final score for reads : 2442
Certainly looks like that RAID card sucks. Unfortunately, I don't know
what those mpt0 alerts are about.
--
Bill Moran
Collaborative Fusion Inc.
http://people.collaborativefusion.com/~wmoran/
wmoran at collaborativefusion.com
Phone: 412-422-3463x4023
More information about the freebsd-performance
mailing list