Tag Archives: RAID

Stardom SOHORAID review

Backups are vital for keeping your data safe, but keeping them in the same physical place as the backed up data has some drawbacks. If your house or office catches fire, or some natural disaster occur, you loose all your data anyway. If the place is robbed, there’s a high probability that the burglars take all the hardware they can find, backup disks included (and it happens to many people, unfortunately, including some indie mac developers).

Facing that, and having the possibility of easily keeping a backup media offsite, I started looking for a solution. My requirements were simple: it had to be fully automatic and give me zero work, besides the obviously needed physical transportation. As I already had a backup system in place (using Retrospect and a backup disk) it was easy to conclude that a nice solution would be a RAID system with swappable drives. This way I could have two mirrored drives online, and a third one offsite. Every time I switch drives, it’s just a matter of taking out one of the drives and later inserting the one that was kept away. The RAID system will rebuild the mirror and, most important, I would have to do nothing!

After searching for a while, I was recommended the Startdom SOHORAID line of products. Don’t be fooled by the crappy site, because, as we are about to see, the product actually surprised me for it’s quality.

There are two models, the SR3610 and the SR3620. The SR3610 is actually the best one, including an LCD display for easy configuration and system monitoring. The SR3620 only has one option, USB2 + external SATA interface, while the SR3610 comes in two options, USB2 + external SATA or USB2 + Firewire 800

As the machine that is driving the system is a PowerMac G5, my first idea was to buy the firewire 800 model. But I ended up getting the USB + eSATA SR3610 option due to a mix of reasons. The first one, the price. The Firewire 800 model was much more expensive (about 70 euros). Also, facing the fact that Apple is moving away from Firewire and that the reliability of firewire controllers is not that great, I ended up opting for the USB + eSATA model. This model has an additional fan to help keeping the system cooler.

I decided that, as the RAID would be only used for backups, USB would be enough. But the Stardom came with an eSATA to SATA bracket that allowed me to turn an internal SATA port in an external one. As I would not need the internal backup disk any more, I got a free SATA port on the G5 and used this bracket to plug the RAID directly to the SATA interface. It was a nice way of adding an eSATA port to the Mac without having to buy a PCI eSATA card.

Stardom sells their RAIDs under OEM to many manufactures, including WiebeTech. As there’s already an extensive and incisive review of a WiebeTech SilverSATA II Dual Bay SATA Enclosure online (which is exactly the same product as Stardom’s) I won’t reinvent the wheel. Instead, I’ll add some points to Arthur’s great work:

Power supply

One thing that surprised me in the Stardom system was the quality of the power supply. As you can see in this Arthur’s photo, the power supply is not an external made-in-china low quality brick, but it’s built in the case itself. And those big capacitors are actually making great work there. Remember on the old Macs where you would turn off their switch, and they would take about half a second to actually power down? Well, here is the same thing. After cutting off the power, the system will still work for about the same time. This is great to avoid quick power cuts, and shows the power supply appears to be relatively immune to bad quality mains power.

Interface

The LCD panel + control buttons were actually a deception (the only one). First, the menu system is complicated and non-intuitive to use. A good example is the RAID mode, that can be switched between 0 and 1. When you get to the RAID mode menu, it will display one of the modes… that is actually the mode the system is not in. The idea is that, if you want the RAID mode to be that one, you press the ENT button. Well…

But there’s worse. The LCD display, during normal operation, displays the status of both drives. If you try to do anything else, including monitoring the system temperature of fan speed, the RAID operation will stop. The LCD will display a warning about this, and if you confirm, no disk activity will occur while you are on the menu system. This is pretty bad, because you won’t be able to constantly monitor the system health during operation.

Also, I have noticed that, sometimes during the internal controller initialization, after powering on or resetting, the LCD panel will display random characters. Despite being scary, it has no apparent side effects related to the data consistency and disk operation.

Finally, I also don’t get what the drive leds are supposed to mean. Each drive has an operation led on it. When writing data, the leds on both drives will light up. When reading, sometimes only the upper drive led lights up, and sometimes no led lights up at all. At first I thought the system was only reading from one drive, but according to the speed tests I made, both drives must be in usage, as a single disk cannot sustain the +70 MB/s I got (you can see more speed tests in Arthur’s review). So I suppose this is just a controller bug, again, without any visible harmfull effect on the data reliability or normal RAID operation.

Bottom line, this is something that Stardom needs to improve.

RAID reliability

As I intend to keep removing and inserting drives in this thing, I wanted to be sure how reliable the RAID system was. To test that, I created a RAID mirror using two disks, and copied some big video files to it. To test the consistency during the tests I describe next, I used the command line md5 tool to create a hash of the original file (on the G5′s internal drive) and the files in the RAID. As long as both hashes are the same, the files are not corrupt.

First, I did the obvious: removed a drive. A very loud “beep” started sounding from inside the box, and the status led turned yellow. I pressed the mute button to bring back the peace, and tested consistency. Everything OK. Then I inserted the drive I had just removed. The system started rebuilding the RAID. I did consistency checks during and after the RAID rebuilding process, and everything was OK.

But this is lame. The system did what is supposed to do. Big deal. Next test was a little more agressive. I removed a drive again, and reinserted it. The rebuilding operation started as expected. Then, at about 2% of the rebuilding process, I turned the system off, to simulate a power failure. As this is not exactly a high-end expensive RAID system, I expected a disaster. Well, much to my surprise, not only the system started rebuilding the RAID mirror immediately after being powered on again, as it actually knew where it was before being turned off, and resumed the process from there! Again, consistency checks were done during and after the process, and everything was fine. Thumbs up for the Stardom people!

Noise

This thing has two hard drives, a RAID controller and a power supply inside it, so it really needs to cool itself down. Cooling down means generally fans, and fans mean noise. On of the great things I felt when I upgraded from a PowerMac G4 to a G5 was how silent my office become. The PowerMac G5 has very high-quality fans that turn only as fast as needed, which means they turn very slowly and quietly most of the time. I was afraid the Stardom enclosure would bring the noise back.

To my surprise, it’s much more silent than I expected. Arthur told that in his review, and I do the same: you’ll hear mostly the air flow through the enclosure and not the fans themselves. Of course, it makes noise, and it’s clearly louder than the G5, but it’s not that bad. To get an idea of it, if you play some game on a MacBook Pro and bring its fans up to full speed, the MacBook Pro becomes much more noisier than the Stardom RAID.

Conclusion

The Stardom SOHORAID seems to be a great system, specially being cheaper than most concurrent products. It’s very reliable, and seems to be made out of quality components. It’s also fast (if used through the eSATA interface) and quiet. The only bad thing about it is the user interface, specially the fact that using it will halt the normal RAID operation.

Promise UltraTrak woes

So, we have in your department a Promise UltraTrak SX8000 RAID system that we use for backups. This mother can drive 8 PATA hard drives in several RAID modes, and expose them through a SCSI interface. We currently have a RAID 5 array using 4 500 GB Hitachi hard drives and a fifth hard drive, similar to the other 4, to be used as hot swap if one of the other drives commits suicide during the night. This is plugged to a PowerMac G4 that has the boring task of carrying up all our backups while we are all sleeping like babies.

This is a pretty old product, and it was never tested with drives this big, but the fact is that it has been working flawlessly for months now (since we upgraded the original 120 GB drives). Until last week. As I had some empty bays and unused small drives, I thought about doing a second array to store some archive stuff, as the RAID 5 array is getting pretty full.

I remembered that the case controller reboots itself when the user creates a new array, so I opted for turning off the Mac and the Promise itself, and install the disks with everything shut down. You know, this thing has hot swap, but it’s getting old, and we don’t want to push it too far. So let’s play it safe. Big mistake. Big big mistake.

I pop in the drives, press the power switch. Controller boots itself up and, as Steve Jobs would say, boom! The first two drives had the red led of death glowing. I spent a quite dramatic few minutes looking at the damn thing, and thinking that it happened. The least likely, the most feared of all things that could happen on a RAID 5 system had just happened. Two drives failed. At the same time. All the backups, some of them more than one year old, lost. Forever.

I got rational again and thought, no, this can’t happen, this thing did not boot correctly, there is something with the drives I’ve just inserted that is screwing this up. I powered down the case, removed the drives I had just inserted, and powered on again, this time carefully watching all the lights and bells. The Promise RAID, when booting, scans all the bays to see what’s going on there. You can see that happening by watching the drive lights, all of them blink quickly in a slow sequence. Well, the first two weren’t blinking.

I thought, hum, bigger drives then expected, too much time to spin up, the controller is testing them too soon. I powered off the damn thing, removed the first two drives, and reinserted them on lower bays. Another big mistake. The array disappeared. It was lost forever. Looks like the drive position is crucial for the arrays to be recognized. I had just killed what was left of it.

After some moments of desolation, I went to recreate the array again, assuming that the backups were lost I had to start from the ground up. I started the process of creating the array, and then I saw the light. On the little LCD display, the controller had the best of the words I could see on it’s first line: INITIALIZE. It allowed me to choose Yes and No. I stopped for a while, and though, if the hard drives are OK, and if I can create an array without any kind of initialization… all my data will be there! Right?

Power off, insert the drives on the original positions, power on, create array, RAID 5, default block size, initialization OFF, gigabyte boundary on, and GO. The array was created. No activity on the drives whatsoever. Perfect. Reboot. I fired up the G4 and run to the KVM console. OS took ages to boot (actually it took as long as every other time, but the adrenaline was all around). The desktop appeared and… YES! There was the RAID volume, as if nothing had ever happened. I did some quick tests, but that was it. The RAID was back in all it’s glory. Months of backups, saved.

Knowing this, I decided to push my luck a little further and turn the RAID off again. After powering up, the history repeated, first two drives were “dead”. I simply destroyed the array, created a new one without initialization, and I was back in business. Then I turned it off and quickly on again, not allowing the drives to spin down to a full stop. That time, the controller booted up correctly and the array was online.

I went to Promise site to check on this issue, and I see they had released a new firmware that announced to support some newer drives. I installed it (and it was a terrible experience, it started by having to download an older firmware to get the updater software, as Promise forgot to pack the software together with the new firmware on the ZIP archive, and ended up with an old PC with a serial cable plugged to the RAID, two floppy disks – yes, two floppy disks, and yes, we are in late 2008 -, one with DOS, another with the software, and about 30 tries – power cycles on the Promise RAID and software reloads on the PC – to get the serial communication working). After that, I powered off the RAID, waited for complete spin down, powered up again, and everything worked fine. Although I’m not trusting it fully, it looks like the problem might be solved.

So, lessons to learn: if this happens to you, 1) Do not panic (yet); 2) Do not change the order of the drives; 3) Use the LCD display and the buttons to obtain all the settings of the array (block size, gigabyte boundary status, etc); 4) Delete the array; 5) Create a new array with the same settings and initialization off. You should be off the hook by now, unless the problem WAS in fact two drives dying at the same time. Which, you know, doesn’t happen. It just can’t. Really.