By Philip Churchill on January 20th, 2010
The Man Behind Drive Extender
Lead program manager on the Windows Home Server team Mark Vayman chats about his role on the team in this short 3 minute video.
Mark who is an engineer on the development team and is the owner of the storage stack (Drive Extender) in WHS, has a home built Home Server at home which has 8TB of storage space for his collection of videos, photos and recorded TV.
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Mark,
Boy do I have a question/comment for you 🙂 Read on….
Jim
A Cautionary Tale:
As a small video production house we were looking for “Very Reliable” storage that was easy to use and share with our staff. We have been using a Drobo for the past 3 years with 2 terabytes and not had any issues. When the HP media servers where released we saw we could add more storage and decided to give them a try. Our first purchase was the HP EX475 and we loaded it with 4 terabytes. We then upgraded to the EX485 with 6 terabytes. We did not have problems with the units except they always seemed slow on data transfers especially if you tried to stream vob or avi files it was choppy.
We then upgraded to the EX495 when that was released and loaded it with 8 terabytes. Not sure how anyone migrates data from these units but for us we used Second Copy which does an excellent job of migrating data safely and accurately from one system to the next without any issues.
Our EX495 performed much better with data transfers and streaming videos (not perfect, but better). The only software we added was Diskkeeper . We had added around 7 terabytes of videos and 600 gig of mp3 files and 50 gig of photos. We were running out of space so we added an “iStoragePro iT4ESA external Tower Storage” (http://www.mediasmartserver.net/2009/10/27/review-istoragepro-it4esa-esata-storage-enclosure/) and 2 drives for 4 terabytes more of storage which brought us up to 12 terabytes of storage. For data duplication we just had the photo directory setup for we felt if there was a drive failure we had enough extra storage that we could remove the bad drive without any issue.
All seemed to go well for another month until three days before Christmas and then we noticed our little house in the bottom right corner had turned red. Upon logging in our server console we saw the error message “The Drive Extender Migrator Service is not running”. Well that was new to us so we looked it up on the web and found other people have had this problem and there seemed to be a solution. The solution was to restart the service, seemed simple enough. The problem was when we tried to start the service it would not start. To save time we opened a case with Microsoft for $79. The technician at Microsoft took over our server and played around for it for over an hour just looking at logs and following the steps from http://support.microsoft.com/kb/939426. At the end he said he had to escalate it to level 2 support and they would call me tomorrow.
The next day level 2 support called me and went over the notes from the other technician and said the only thing he can do is what was written in their support bulletin and I would have to call HP to open a case. I told him you have to be kidding for charging me $79 for support and all they did is the same thing I did by running the commands found on the support bulletin. I told him that having me call HP support is really not offering me any Microsoft support and that I should not pay for this. He agreed and said he would process a refund which they did.
I called HP and spoke with a WHS engineer and he had me load the “Toolkit” addin so I could send him the system logfiles. He also mentioned to me that HP does not support the use of any external storage devices since they have not tested them. I emailed the logfiles to him which were around 20 meg.
The next day he sent me the following email:
Jim
After reviewing the logs, it appears there is an abundance of server errors.
It would appear that a server recovery would be required to put it back to
100% operation. In the future, please resist the temptation to remote into
the operating system of the server, as it can cause irreversible problems.
Attached below are the instructions for performing both types of recovery ->
please choose “Server Recovery” to retrieve all current data:
I followed his instructions and within an hour the server was backup or so I thought. Upon looking at the home screen I noticed instead of having 3 terrrabytes free we now had 4 free !! A loud yelp went off in my head, like why am I missing a full terabyte of data. I then went looking at our video folder and upon opening it, it looked ok I could see a lot of our clients folders. I then went to our photos folder and they looked ok, I then went to our Music folder and BAM almost empty. I did a size check of the folder and it showed only 10 gig out of 600 !!! Where is the missing 590 gig of music ??
I then opened up our converted video folders which was 60 gig and it looked like it was ok until I drilled down a little further and clicked on a few folders only to find nothing inside of them. I did a size check and saw they only contained 1 gig of data out of 60, more missing files !!!
We were sick for this was our main storage unit and had consolidated all our backups on this unit. We never expected the unit to have a software problem so this took us by surprise.
I called HP and spoke with an engineer who said he heard you can RDP into the box and look at the drives and you will see hidden folders and you can unhide them and all your data will be there. I immediately hung up the phone relieved that my data would be there only to RDP in, find the hidden disks and see that my data was NOT there, nothing, nada, zero. I called back and spoke with another engineer who told me that sometimes when the operating system is restored the data goes missing something about the tombstones are not rebuilt properly. They are not sure how this happens but it does happen. He told me to pull each drive out and then use some kind of disk recovery software to find my files.
I pulled the drives and tried a number of software packages and only a couple would even see the drive one of them was “Stellar Information Systems Ltd.” The software immediately recognized my drives and the missing folders. I thought I was golden for it listed our whole music folder with all the songs. I had the program recover all the music to another drive which took around 8 hours. I was ecstatic for we got our music back, so I thought. It turned out that none of the songs were playable, all the media players said the song was corrupted. Steller tech support had me email them some of the songs whereupon they wrote back and said the files contained garbage for the system must have overwritten the data area.
I then took a closer look at our video folder and noticed that the folders did exist but like our other converted video folder there was no data in around 50 folders. I also noticed that some videos were now stored in our music folder and some of the music folders where now stored in the root of our video folder. Also some of the videos were duplicated by being stored in both the music and video folder. This whole thing is one big mess.
Thank god we still had our old EX485 with all the music on it and most of the lost videos, we did lose around 10 gig of data which we will replace. Right now our EX495 is sitting in a corner by itself for everyone is afraid to use it so we are back using the Drobo
Needless to say we are very dissatisfied with the reliability of this unit for we consider this a catastrophic failure of the system architecture. How could we be sold on an appliance that is suppose to protect data when in fact it loses data. I agree we did not have data duplication turned on but I am wondering if we had would we still have had an issue. We have lost complete faith in this unit/architecture and will go back to using a RAID system for we have never experienced any crazy issues with it.
I don’t think I am alone with these issues and I think Microsoft should take a better look at the software architecture and correct which could be fatal mistakes for consumers. For this is definitely not a sell tag line for the unit.
Maybe Mark you can address this issue and how to prevent it in the future and restore our confidence in the unit.
Jim Johnson