CHRISTOPHJPETERChristoph Peter

This error showed up when a friend asked me to fix this 2 TB Western Digital MyBook Studio Edition Drive. The drive can not be mounted, repaired or verified.

invalid BS_jmpBoot error

Long story short there is no way to simply fix this error. You can try with TestDisk but I had no luck with it. Don’t jump out of the window just yet since your data is most likely still there. Only the partition table on the drive is damaged and all your data is still in place. Any Data Recovery tool will be able to get your data out of that damaged partition.

If this happend to you consider reading this link

A sad but typical story about why one needs to use backups when dealing with computers

Last Night a friend of mine gave me his almost full 2 TB Western Digital Studio Edition that has a 2 drive RAID 0/1 built in. He told me that he used it with his mac and everything worked just fine. When he connected it to his PC and tried to move some data to the drive it stoped working, which is no surprise since the drive is formated as HSF+ in a RAID 0 configuration. Windows can not handle HFS and somehow managed to serverly damage the pratition table on the drive. After using all tools known to me such as TestDisk, Mac OS X disc utility and Ubuntus partition manager i gave it up as damaged beyond repair. The next step will be to use a data recovery tool to pull out the data, that is still intact on the drive, but all of these programs cost at least 100$. In addition we have to finde 2 Terabytes of free space to recover the data to which also will not come cheap.

Since he used the drive in a RAID 0 mode there was no backup anyway but the very same thing could have happened if it was set up as a RAID 1.

When putting together my home server setup I was considering using one of these RAID drives vs. two stand alone drives and I am glad I chose the two single drives.

Pro RAID

• the consumer versions like the western digital ones are really easy to set up
• good protection from hardware failure
• automatic data restoring
• only Raid 1 will give you some sort of backup
• RAID 0 gives you speed gains
• usually the read feature is a bit more costly than two stand alone drives

Contra RAID

• no protection from software errors
• if the RAID it self craps out on you there is very little chance on restoring things
• if you delete stuff it is gone on both RAID discs instantly
• if the partition is damaged both drives are affected
• the physical proximity of these raid drives makes it more likely to die together in case of power surge for example
• not very flexible – I can always grab one of my two storage drives and go to a friends house to get some data and when I get back home it just syncs to the other drive and everything is fine unless the unlikely case of both drives die at the same time

I do not recommend a single RAID 0,1 or 5 setup as a sufficient backup solution. Backup often, on different devices in different locations!!

today I published my first air application, called iSurveill. A simple webcam surveillance application that takes snapshots with a webcam and saves them to the computer. It’s not very sufisticated but as a first try it will do. The application is now available on my website http://www.chrillo.info/isurveill/ and hopefully it will soon be available in the adobe air market place.

BACK UP OFTEN!!!!

Now that I have my mac mini set up as my home server I also wanted to backup its system drive to preserve all the configuration. I have an Airport extreme basestation that has a 500GB hard drive hooked up to it. I have used it to back up my mac book pro over the air and it worked just fine. When I tried to select it as the backup drive for my mac mini the time machine preference pane would crash every time. So I played arround with it and it appears that time machine is now able to backup to any afp:// file server. It is important that you mount it using the following instructions and not just click on it in the finder. It appears that apple does something differently when using the shares in finder.

Setting up time machine with a remote destination

This is done by pressing command + K in finder and using OS X built in ability to connect to different file servers

connect to server

You might get prompted for user name and password. Once connected the afp source shows up in your finder.

afp source

In my case that is the airport extreme base station called chrillo.Airport with the hard drive. This could also be another mac. Now head over to your time machine preferences and the click the change drive button.

remote time machine backup

As you can see it shows up with its Ip address. In my case I used the internal Lan IP