Continued from here. I got the disks out to the colo facility, and swapped them in. At first, things didn’t come up right because it didn’t have a network. Funny, because I’d remembered to fix /etc/network/interfaces and /etc/resolv.conf back to the values they need in the colo facility before I’d shut down at home. Grepping through the dmesg results showed that for some reason, eth0 had been renamed to eth2 and eth1 had been renamed to eth3. Something tickled my memory about the last time I’d been through this – it remembered the MAC addresses on the machine you set it up on, so when it boots the new machine it thinks “aha, I already know where eth0 and eth1 are, so these new MAC addresses need to be mapped somewhere else”. Unfortunately my own blog was down, so I couldn’t find what I’d written about this before, but a quick google on my iPhone and I removed /etc/udev/rules.d/70-persistent-net.rules, and rebooted, and it all came up.
Made sure I was talking to the net, and I could ssh into it from home, and then started up the guest domains. Made sure they were up and talking to the net as well. Made sure one of my web sites showed up on my iPhone. Buttoned up and went home.
Once I got home, I made some further checks that everything was up. As far as I can tell, it is. Now to run tiobench on the updated system.
Let’s have a look at some of these compared to the results I got with the Caviar Green disks running on the same hardware.
| Test | Old | New |
|---|---|---|
| Sequential Read best rate | 44.49 | 168.26 |
| Random Read best rate | 0.39 | 1.37 |
| Read Max Latency | 1036.44 | 743.22 |
| Sequential Write best rate | 10.36 | 82.46 |
| Random Write best rate | 0.09 | 1.76 |
| Write Max Latency | 143896.67 | 1748.55 |
Basically the huge latency will be the biggest difference. I don’t know if that’s because of the WD Caviar Green “spin down” or because there were disk errors, but either way, it’s going to be a relief to see some performance again.
Raw results after the cut.
Unit information
================
File size = megabytes
Blk Size = bytes
Rate = megabytes per second
CPU% = percentage of CPU used during the test
Latency = milliseconds
Lat% = percent of requests that took longer than X seconds
CPU Eff = Rate divided by CPU% - throughput per cpu load
Sequential Reads
File Blk Num Avg Maximum Lat% Lat% CPU
Identifier Size Size Thr Rate (CPU%) Latency Latency >2s >10s Eff
---------------------------- ------ ----- --- ------ ------ --------- ----------- -------- -------- -----
2.6.32-5-xen-amd64 2000 4096 1 90.72 14.62% 0.042 88.98 0.00000 0.00000 620
2.6.32-5-xen-amd64 2000 4096 2 139.62 46.10% 0.055 414.77 0.00000 0.00000 303
2.6.32-5-xen-amd64 2000 4096 4 171.20 118.0% 0.084 351.52 0.00000 0.00000 145
2.6.32-5-xen-amd64 2000 4096 8 168.26 216.7% 0.150 743.22 0.00000 0.00000 78
Random Reads
File Blk Num Avg Maximum Lat% Lat% CPU
Identifier Size Size Thr Rate (CPU%) Latency Latency >2s >10s Eff
2.6.32-5-xen-amd64 2000 4096 1 0.77 1.382% 5.063 132.75 0.00000 0.00000 56
2.6.32-5-xen-amd64 2000 4096 2 1.31 1.775% 5.864 249.70 0.00000 0.00000 74
2.6.32-5-xen-amd64 2000 4096 4 1.29 4.262% 11.323 141.83 0.00000 0.00000 30
2.6.32-5-xen-amd64 2000 4096 8 1.37 8.436% 17.121 250.18 0.00000 0.00000 16
Sequential Writes
File Blk Num Avg Maximum Lat% Lat% CPU
Identifier Size Size Thr Rate (CPU%) Latency Latency >2s >10s Eff
---------------------------- ------ ----- --- ------ ------ --------- ----------- -------- -------- -----
2.6.32-5-xen-amd64 2000 4096 1 82.46 38.08% 0.044 836.08 0.00000 0.00000 217
2.6.32-5-xen-amd64 2000 4096 2 57.11 48.59% 0.126 1651.86 0.00000 0.00000 118
2.6.32-5-xen-amd64 2000 4096 4 66.19 104.4% 0.215 1418.43 0.00000 0.00000 63
2.6.32-5-xen-amd64 2000 4096 8 66.08 214.7% 0.418 1748.55 0.00000 0.00000 31
Random Writes
File Blk Num Avg Maximum Lat% Lat% CPU
Identifier Size Size Thr Rate (CPU%) Latency Latency >2s >10s Eff
---------------------------- ------ ----- --- ------ ------ --------- ----------- -------- -------- -----
2.6.32-5-xen-amd64 2000 4096 1 1.76 0.135% 0.006 0.05 0.00000 0.00000 1302
2.6.32-5-xen-amd64 2000 4096 2 1.55 0.158% 0.006 0.13 0.00000 0.00000 977
2.6.32-5-xen-amd64 2000 4096 4 1.52 0.972% 0.006 0.18 0.00000 0.00000 156
2.6.32-5-xen-amd64 2000 4096 8 1.52 1.086% 0.011 8.02 0.00000 0.00000 139
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