For the good of all of us - Hardware

Resetting SATA devices under Linux

nospam@example.com (Ralf Ertzinger) — Wed, 18 Nov 2009 13:36:49 +0100

Note: this was tested only on SATA attached optical drives, not on hard disks. Removing a hard disk with mounted partitions on it (directly or indirectly) is probably not a very smart idea.

A device name of /dev/sr0 is assumed.

Find out which controller the device is attached to (we’ll need this later):

# readlink /sys/block/sr0
../devices/pci0000:00/0000:00:1f.2/host1/target1:0:0/1:0:0:0/block/sr0

The interesting part if the answer is host1, which identifies the controller.

Disconnect the device

# echo 1 > /sys/block/sr0/device/delete

This will remove the device from the bus (logically). Look in dmesg for confirmation.

Rescan the controller

# echo "- - -" > /sys/class/scsi_host/host1/scan

host1 is the identifier from step one. Again, dmesg should show the device being rediscovered.

Experiences with the MSI support

nospam@example.com (Ralf Ertzinger) — Fri, 13 Feb 2009 15:15:06 +0100

I have to say that I am very pleased with the technical support I have received so far from MSI for my IM-GM45. Besides the MTRR issue I wrote about here, I had filed a second, minor request.

The second request regarded the shared video memory setting for the on-board graphics chipset. In the original BIOS the minimum amount of memory that could be allocated for video RAM was 32MB, which is way too much for the text mode that I need. So I filed a request asking for the possibility to select a lower amount of memory (preferably 1MB or less).

Two business days later I received a mail from the MSI support containing a BIOS with the fix for my specific request (fortunately it also contained the MTRR-fix).

This is admittedly much more than I expected. Thanks to MSI for the quick and helpful response to both of my requests.

Building an OpenSolaris storage - Hardware, Part 2

nospam@example.com (Ralf Ertzinger) — Sun, 08 Feb 2009 14:57:31 +0100

Earlier this week the last of the hardware I ordered arrived, so I could finally assemble the whole system.

Left: CPU, right: packaging

Contrary to my expectations the CPU did not come with a fan (which was just as well, as I already had two), but with a lot of packaging instead. Someone at Intel should think about cutting down on all that plastic just to ship a tiny piece of silicon.

Speaking of silicon, contrary to almost all other current x86 CPUs the Core2Duo Mobile processors do not have a metal cap to protect the die, but the die instead sits rather unprotected on top (similar to the Athlon XP and Pentium 3 processors). This makes attaching a fan an interesting experience, because it is quite easy to damage the die while doing this.

The mounted board with CPU and RAM

Coolermaster is obviously aware of this, the contact side of the fan contains a foam spacer which surrounds the die when the cooler is placed on the CPU and which is supposed to prevent tilting. The cooler is then fastened to a mounting plate sitting on the bottom of the board using some spring screws. This works insofar as I was able to mount this without damaging the die.

Getting all this into the case is a bit tricky but manageable, as the mainboad tray can be pulled out from the case. The case has qute an assortment of LEDs and switches, unfortunately not all of these have corresponding connectors on the board (the two LAN-LEDs, the ERROR LED, the Mute switch and the intrusion detection switch). The SATA cables are numbered which makes it easy to plug them into the right connector, so the mainboards view of drive numbering lines up with the numbers on the case.

After putting all this together I switched the system on for the first time. All went well and the BIOS came up. The system is not exactly quiet, but I find the noise far more bearable than the Thecus one, mainly because most of the noise is airflow, and not the droning of the fans. The noise level is constant, too, so far I have not heard the case fans increase speed.

Next up: installing software

Building an OpenSolaris storage - Hardware, Part 1

nospam@example.com (Ralf Ertzinger) — Sat, 24 Jan 2009 17:32:04 +0100

Today the first half of my order arrived: the case, the mainboard and the fan. As this delivery was somewhat unexpected (the mainboard is a new model, and I had expected it a week later), I now have new hardware I can not use, due to the lack of a CPU. This is a bit embarassing, but cannot be changed right now, so I’ll start with what I have.

My apologies for the appaling quality of the pictures, but all I have in the way of digital image capture is the camera in my cell phone.

The Case

Outside of the case

The first thing I noticed about the case is how solid it looks and feels. Contrary to the photos I had seen so far the case is not all black, but the sides and the top and bottom are a dark siverish grey. The front, however, is black. I have to say it looks quite good.
Although the front and sides are plastic, there is absolutely nothing cheap about the feeling. This is underlined by the weight of the thing. Even though there is no power supply in it (that is external), and no parts have been mounted yet, the empty case weighs over seven kilograms. Under the plasic outside panels there is a massive metal cage. It really has a no-nonsense feel to it.

Inside of the case, sans mainboard

The inside is full of pre-routed cables that lead to the front panel, the power distribution plane and the hard disk backplane. The case has a 20+4-pin ATX power connector plus the four pin additional CPU power connector most current boards need. Luckily, all the MSI board requires is the 20-pin ATX connector.

A pleasant surprise (aside from the colour) was that the case has a multi-format card reader already built in. From the manufacturers site I had gathered that this was an optional extra, but my case came with one included.

Also included is a CPU fan, but that is quite specific for a certain mainboard, and will not fit most other boards, so it is useless to me.

What is not included is a manual, at least I have not found any. As all of the cables are clearly labeled this is not much of a problem, though.

The Board

Mainboard, cables and stuff

The mainboard comes with the usual assortment of cables (2xSATA, 2xSATA power adaptor, 44-pin IDE) and the rear panel bracket. In addition, it also contains a CPU fan, which surprised me. It also is a Coolermaster model, but not the same I ordered extra. If, as I suspect, the CPU also comes with a fan I’ll have quite enough of those things.

Underside of the board, with the fan coupling plate mounted

The board also had a pleasant surprise, this one on the bottom of the board. MSI put a CF card socket there, which the web site stated as an optional extra. I think I’ll use a CF card instead of the notebook hard disk,
as this produces less noise and heat.

The Fan

Well… it’s a fan, right? Goes on the CPU, and hopefully does not make too much noise. I can always threaten it with the other fan if it does.

Building an OpenSolaris storage - History

nospam@example.com (Ralf Ertzinger) — Sat, 24 Jan 2009 17:04:35 +0100

This is supposed to be a documentation of my endeavour to build an OpenSolaris based storage machine for my home use. Coming from a Linux background myself it will also serve as a notebook of how to do stuff under Solaris.

History

For years I had a midi tower based system running, which was both my internet router and the local storage machine. This machine was shut down eventually, energy prices being what they are, and was replaced by an ASUS router running OpenWRT for internet access. The storage facility was not replaced, so only the hard drives on the client machines themselves were left. In the middle of last year I finally had enough of that and started looking around for a small storage appliance. I wanted something I could play around with, so being able to screw with or replace the original operating system was a must.

I ended up with the Thecus N2100, which is a small, ARM based NAS enclosure running Linux from embedded flash, and able to house two SATA hard disk drives. It’s possible to get a fully functional Debian system on it if you’re not afraid of poking around with serial ports (which I am not), so it seemed like a good choice. It was ordered together with two Seagate 7200.11 1TB drives.

It turned out pretty fast that the Thecus and the Seagate drives did not like each other a whole lot, which is probably due to the rather high spinup current that the Seagate drives need (3A on the 12V rail). This was more than the Thecus could provide, so the drives did not spin up most of the time. So the two Seagate drives were replaced with two Samsung 1TB drives, and the Seagates were banished to the shelf.

In hindsight this was probably a good thing, because a) the Seagates did not have time to fill up their log and run into the current firmare bug, and b) I had 4 1TB drives lying around, which would come in handy later.

The Thecus liked the Samsung drives a whole lot better, and the original firmare was quickly replaced with a Debian Lenny distribution. From a purely administrative standpoint all this worked very well, the distribution detects all the hardware in the system (not that there is a whole lot of it, but nonetheless), including the multi-coloured LEDs in the front panel and the fan controller.
Debian duly provided me with NFS and SAMBA based storage, a print server for the printer connected to the USB ports, and several other services.

The main problem with the Thecus was speed. The system is equipped with a 600MHz ARM processor, which sounds quite beefy, especially compared to the other NAS storage enclosures out there, which usually have less.
In reality it is not a whole lot. None of the individual subsystems are epecially fast on their own (the system has two 1GB network controllers, but trying to get 100MBit directly from memory is pushing things, and the storage controller has problems of it’s own, also limiting the possible performance). The net result of all this was that getting more than 5MB/s read or write performance was pretty much out of the question.

As this was unsatisfactory a new solution was needed. In the mean time I had played around with OpenSolaris (in the form of the bi-weekly nevada snapshots), and was quite impressed by it’s ZFS file system. So I wanted
to build the new system around this OS, in order to try it out in real life with more than just a few megabytes of test disks.

This meant using an Intel based machine, though (getting a Sparc based enclosure seemed to push my luck), so I started looking around again. Thecus offered a five disk hot-swap enclosure (the 5200(PRO)) with a 600MHz or 1.6GHz Celeron processor, Marvell-SATA-Controller and Intel Gigabit Ethernet, booting from an internal flash disk. While talking this through with several people on IRC (thanks, ofu!) it became clear that I could get more performance for the same money when building the system myself.

(Ironically, I have gotten my hands on a Thecus 5200 based system as well, so I get to have the best of both worlds. Life is great, sometimes).

I did not want a midi or mini ATX tower though, so choice was getting slim. ofu again pointed me towards the Chenbro 340 case, which has four hot swap cabable SATA bays and takes a Mini-ITX board. Finding a fitting board turned out to be somewhat complicated, as Mini-ITX boards with (at least) 4 SATA ports are rare (in theory it is possible to put a PCI card into the case using a riser card, but I did not want to go that way).
Even more, all the hardware (especially storage and network) had to be supported by Solaris. I figured the safest way to go was getting an all-Intel board (Intel SATA controller, Intel network), as these parts are known to work well.

In the end I chose the MSI IM-GM45, which has four on-board SATA ports connected to an Intel ICH9M-E controller, two Intel gigabit ethernet ports and takes an Intel Penryn processor (among others). It also has an IDE connector, which will drive the boot disk (the four SATA drives will run in a RAIDZ configuration, from which Solaris can not yet boot).
The board takes up to 4GB of DDR2 RAM, which is plenty. It also has wide selection of video outputs (which I do not need at all), and five serial ports, one of which is on the rear panel (which I do need).

The final list of parts for this project is as follows:

Chenbro 340 case
MSI IM-GM45 mainboard
CoolerMaster EPN-41CSS-01-GP cooler+fan
Intel T8100 CPU
4GB RAM

The hard disks are already there (the two Seagates on the shelf, and the two Samsungs in the old enclosure). These will be resused. I also have several old notebook drives lying around, one of which will be used as the boot disk.