The FreeBSD Diary

The FreeBSD Diary (TM)

Providing practical examples since 1998

If you buy from Amazon USA, please support us by using this link.
[ HOME | TOPICS | INDEX | WEB RESOURCES | BOOKS | CONTRIBUTE | SEARCH | FEEDBACK | FAQ | FORUMS ]

Things look quiet here. But I've been doing a lot of blogging at dan.langille.org because I prefer WordPress now. Not all my posts there are FreeBSD related. I am in the midst of migrating The FreeBSD Diary over to WordPress (and you can read about that here). Once the migration is completed, I'll move the FreeBSD posts into the new FreeBSD Diary website.

Dual Opteron - better SATA cables for the Raptors 19 August 2006
Need more help on this topic? Click here
This article has no comments
Show me similar articles

When you need cables, you often need them right now. Fast shipping is great. Overnight is fantastic. It's even better when the vendor calls back and offers you a slightly more expensive cable, for the same price, because the one you asked for is out of stock and will take a few days to order in from the States.

This is the service I got from MyCableShop. I found them via Google, and they had the cables I wanted, at a much cheaper price than my local computer shop could source them. I wanted these 12" SATA cables, and with shipping, they'd be about $5 each. Just what I need to solve a messy cabling issue that arose from using 38" cables in a small 2U case.

Not only did MyCableShop call me to recommand another cable shortly after I placed my order, but the cables arrived the day after I ordered them. I'm impressed.

The new cable layout

cables The new cable layout is much improved. The 12" cables fit nicely between the card and the backplane without any excess blocking the fans. You will notice that I used two red 18" cables. The 12" cables are great for the 6 ports at the back of the 3Ware card. But for ports 6 and 7 at the front of the card, I needed a slightly longer cable. I knew I had several of these cables somewhere in the house, but I could find only one. I headed to my local computer shop (Over The Top Computing) where Chris gave me one he had in the back.

These 18" cables were slightly too long, so I routed the excess to the side of the RAID card. Before I ordered the smaller cables, someone mentioned I could do this for the longer cables, but there was so much excess cable (nearly two feet extra per cable) I thought the right thing to do was get new cables. I'm glad I did.

There is one previous photo of the Raptors but it shows only 6 of the 8 drives. The photo below shows all 8 of the Raptors in their cages.

cables
Are the new cables any slower?

Cables are cables. They should not matter. But I wanted to make sure. So I did a very simple test. How fast is a disk copy with the old cables?

[dan@opti:~] $ time cp -r /usr/ports .

real    1m49.440s
user    0m0.454s
sys     0m10.352s
[dan@opti:~] $ time rm -rf ports

real    0m16.398s
user    0m0.157s
sys     0m2.008s
[dan@opti:~] $ time cp -r /usr/ports .

real    1m47.370s
user    0m0.352s
sys     0m10.593s
[dan@opti:~] $ time rm -rf ports

real    0m17.365s
user    0m0.137s
sys     0m2.084s
[dan@opti:~] $ time cp -r /usr/ports .

real    1m47.481s
user    0m0.439s
sys     0m10.541s
[dan@opti:~] $ time rm -rf ports

real    0m16.547s
user    0m0.133s
sys     0m2.048s
[dan@opti:~] $ time cp -r /usr/ports .

real    1m46.543s
user    0m0.479s
sys     0m10.588s
[dan@opti:~] $ time rm -rf ports

real    0m17.276s
user    0m0.105s
sys     0m2.125s
[dan@opti:~] $

OK, those are pretty consistent times.

Then I change the cables, and nearly die:

$ time cp -r /usr/ports .
real    2m30.969s
user    0m0.406s
sys     0m10.693s

*COUGH*

That's nearly 42% longer, with the only difference being the cables!

This can't be right. And it isn't. Let's try again:

$ time cp -r /usr/ports .
 
real    1m45.426s
user    0m0.438s
sys     0m10.645s
 
[dan@opti:~] $ time cp -r /usr/ports .
 
real    1m45.426s
user    0m0.438s
sys     0m10.645s

[dan@opti:~] $ time rm -rf ports
 
real    0m16.939s
user    0m0.136s
sys     0m2.133s
 
[dan@opti:~] $ time cp -r /usr/ports .
 
real    1m45.467s
user    0m0.575s
sys     0m10.710s

[dan@opti:~] $ time rm -rf ports
 
real    0m19.831s
user    0m0.134s
sys     0m2.300s
[dan@opti:~] $

OK, that's good. It was just a caching issue. Now the times are back to what they were.

Monitoring fan speed/CPU temperature

I had planned to monitor CPU temperature and fan speed using something such as healthd or mbmon. Unfortunately, neither port is of any use with my m/b. It uses the ADM1026 sensor chip which the current version of mbmon does not support. Unfortunately, it looks quite different from the already supported ADM1025/1027.

That's a shame. It seems a pity not to monitor such vital readings.

Next stop!

Now that I have the right cables, the RAID has been set up, and NetSaint is monitoring the array for me, it's time to start install the software for my services. I plan to do that over the next week.


Share
Need more help on this topic? Click here
This article has no comments
Show me similar articles