Friday, February 7, 2014

Solving "grub-probe: error: cannot find a device for / (is /dev mounted?)"

A few days ago I encountered this error, which caused me a bit of head scratching.

There are a few causes for this; if you have your O/S installed on Btrfs, then the problem is most likely that you're mounting the entire partition (which is correct in case of other FSs, but not Btrfs) instead of the subvolume for the root.

The correct mount option is:

$ sudo mount -o subvol=@  
So if for example you want to recover grub, using chroot from a live cd, a sample sequence is:
$ sudo mount -o subvol=@ /dev/sda1 /mnt
$ sudo mount --bind /dev /mnt/dev
$ sudo mount --bind /proc /mnt/proc
$ sudo mount --bind /sys /mnt/sys
$ sudo chroot /mnt

Saturday, January 25, 2014

Sinclair A-Bike review (don't buy - it's broken and unusable)

I'm writing this review to inform potential a-bike clients to warn them about what they're going to get into.

TL;DR: A-Bike may seem an acceptable bike for people doing very small trips. This is not the case; due to a defective design, after some usage, even for very small trips, the bike will break. The problem is that the company ignores clients, so you will end up with an unusable bike.

I've had several folding bikes in the past, and I used them with different patterns. Currently I live in a big city with an extended metro system, and almost no hills. I currently use the bike to do the "last mile", and to go to shops close to my building.

For the first few months, the abike is adequate for this purpose. The upsides are:

  • it's super light
  • it folds quite easily
  • it's not such a big deal to have such small wheels, if one cycles on cycleways
The downsides are:
  • pedaling is hard (very inefficient)
  • the brakes work, but they're not very good
After a few months though, the chain started to skip, more and more, until the bike became completely unusable.

Bear in mind that I used the bike for short distances, less than 2 km every day, in flat roads.

I've done some research, and I've found that this is due to the fact that the inner gears are put under heavy strain, so they slowly wear down.

Bringing them to a bike shop is useless, since the parts are custom. So I wrote the support. They ignored the email. After a couple of weeks, I call. The woman on support says to open the bike, and send them a picture. I have a look at the bike, but the operation requires lots of screws to be unscrewed, so I send them a video instead. The ignore the email again. So I call again, and the woman says some circumstantial lie, then says a technical will call me shortly. Nobody calls.

So now I have a piece of crap that the company refuses to fix, and that shops can't fix, either.

So, to recap: if you want to buy an A-Bike thinking you can do small trips (I've seen other people with it), expect it to break quite quickly, and to have a unusuable piece of crap that the company refuses to repair.

Fortuna Studio Downtown (Zurich) - WATCH OUT, SCAMMERS!

So, this is a horror story about Fortuna Studio Downtown (Zurich, Switzerland). I apologize for the title of this post, but it's important for client to understand who they're dealing with.

TL;DR: They owners evicted us before the checkout date, without any reason, and without notice, while we weren't in the room, because of an error in their schedule, even if I told them in advance that they had an error (they ignored me). They didn't help at all, and refunded the expenses for a night at another hotel, after a month of complaints. They said plenty of lies to cover their continuous negligence.


We (2 people) booked the studio-apartment for a few days (Thursday, checkout on Monday), via; I had a sports competition, and I wanted a very simple room.

First of all, the advertisement on the booking website is false - it says that there is air conditioning in the room, while there isn't. Good luck when the temperature goes over 30°.

On Friday, I call them asking if I could do a late check out on Monday. They say that would be ok, but that the checkout is on Sunday. I say that they're wrong, but they reply that they have it in their schedule. I explain that I have the booking confirmation in front of me, and it says checkout out on Monday. They say that it's ok and they will check.

During the Sunday I do my competition, early morning to late evening, and come back after midnight. I find everything outside the apartment, and the lock changed. I turn on my mobile, and find that they wrote me several messages, during the day, warning me that they were about to evict me.

I call back and tell them that I've told them already that my booking was until Monday, and I ask them why they didn't listen. They say the would call back in 5 minutes. They call me and they say that they've done a mistake.

They don't come to fix the problem and pay, but they say that they will pay for a taxi and a room in another hotel.

So we carry everything down from the third floor, including a 15 kg 130x95x40 cm box (no elevator, and very narrow staircases), we take a cab, and we move to the other hotel.

All of this took more than a couple of hours, and we were exhausted - I just had a 16 hours-long competition.

After a week, they still didn't refund us. I call, and they lie, saying they would have completed the payment shortly.

After a couple of weeks, they lie again with the same story.

After a month, I ask their legal address, so I can initiate a lawsuit. They say a circumstantial lie, saying there has been a misunderstanding (again!), and that they would have refunded us shortly.

Finally, the payment comes, with a miserable additional refund of around 20€.