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RAID Migration and Data Corruption


Technogod
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I decided to add another hard drive to my RAID 5 array. Shortly after adding the Hard Drive WHS 2011 reported there were errors on the disk. The disk only contains TiVo video files. I opened up a command prompt and ran chkdsk /f /r on the disk. The data checking was taking so long I aborted the process.

 

I went through all 627 video files and deleted the ones that wouldn't play. None of the files showed up in the recycle bin. Don't ask me why. I ran WHS check and repair on the disk and it fixed the errors. I know there were some videos that had poor or no signal due to my cable provider. I stil think there was something going on because there was corruption on the majority of my latest videos.

 

Don't be alarmed if you add a drive and the migration takes forever. System still seems to be functioning normally with very low overhead. I have an Intel ICH10R controller. There are three 1.5TB dives and I added a fourth. Migration has been running for five days and it is at 37%.

 

Moral of this story is don't trust your precious data to RAID 5.

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I decided to add another hard drive to my RAID 5 array. Shortly after adding the Hard Drive WHS 2011 reported there were errors on the disk. The disk only contains TiVo video files. I opened up a command prompt and ran chkdsk /f /r on the disk. The data checking was taking so long I aborted the process.

 

I went through all 627 video files and deleted the ones that wouldn't play. None of the files showed up in the recycle bin. Don't ask me why. I ran WHS check and repair on the disk and it fixed the errors. I know there were some videos that had poor or no signal due to my cable provider. I stil think there was something going on because there was corruption on the majority of my latest videos.

 

Don't be alarmed if you add a drive and the migration takes forever. System still seems to be functioning normally with very low overhead. I have an Intel ICH10R controller. There are three 1.5TB dives and I added a fourth. Migration has been running for five days and it is at 37%.

 

Moral of this story is don't trust your precious data to RAID 5.

All robins are birds therefore all birds are robins. B)

Seriously, I'm not following the logic. I believe you are concerned that there is a significant amount of corruption on videos recorded after you expanded your array. There could be a cause and effect relationship there, certainly, but you admit there were cable signal problems and your hard drive reported errors. Assuming you mean the new drive you added to the array, why would that and your cable signal issues indicate a failure in RAID 5 technology? Sounds like a bad hard drive and bad cable to me.

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Some older files wouldn't play because of signal problems. The majority of the newer video files that wouldn't play were caused by corruption. I don't feel it's a drive problem because during two previous verification it found errors but no bad blocks. Check and Repair also found no disk problems.

 

Update, tried to copy files between folders on the drive and it brought the system to its' knees. It took hours to copy two video files apprx. 9.36GB. Trnsfer rate was 751K/Sec. instead of the usual 100 MB/Sec.. So much for migration not causing any problems.

 

I'm not a big fan of RAID right now.

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I'm finding more corrupted files today and Windows doesn't even know they are corrupted. When the migration finally finishes, if it ever does, I'm done with RAID. I've never been a big fan of RAID and have had troubles with RAID in the past. AllwaySync between two drives is looking better and better for my purposes. It's a shame I had to learn this the hard way by losing data. RAID is way too cumbersome. Migration and verifys take way too long and impair the performance of the system. I need my server to perform properly and not lose data all of the time and not some of the time.

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I decided to add another hard drive to my RAID 5 array. Shortly after adding the Hard Drive WHS 2011 reported there were errors on the disk. The disk only contains TiVo video files. I opened up a command prompt and ran chkdsk /f /r on the disk. The data checking was taking so long I aborted the process.

 

I went through all 627 video files and deleted the ones that wouldn't play. None of the files showed up in the recycle bin. Don't ask me why. I ran WHS check and repair on the disk and it fixed the errors. I know there were some videos that had poor or no signal due to my cable provider. I stil think there was something going on because there was corruption on the majority of my latest videos.

 

Don't be alarmed if you add a drive and the migration takes forever. System still seems to be functioning normally with very low overhead. I have an Intel ICH10R controller. There are three 1.5TB dives and I added a fourth. Migration has been running for five days and it is at 37%.

 

Moral of this story is don't trust your precious data to RAID 5.

 

I do not agree as I just completed a similar migration on my Highpoint with no corruption issues. I was not please with the performance of the completed array and it did take forever but the data was completely intact when completed. You certainly want a backup on any technology especially when you do something like but it is a bit unfair to blame the raid 5 technology. I will be doing a second one in next two days and will be posting videos on the entire process.

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I really don't trust RAID 5 technology. The only way to have decent performance is to enable write back caching. My UPS failed and the system crashed with write back caching enabled. System did a verify and found errors. Did it fix the errors? There was no further information or instructions. I definitely wouldn't recommend it to a customer and Microsoft doesn't recommend running it on WHS 2011.

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I really don't trust RAID 5 technology. The only way to have decent performance is to enable write back caching. My UPS failed and the system crashed with write back caching enabled. System did a verify and found errors. Did it fix the errors? There was no further information or instructions. I definitely wouldn't recommend it to a customer and Microsoft doesn't recommend running it on WHS 2011.

 

 

For starters, the implementation of the write back cache is a different on a motherboard controller than it is on a stand alone controller. I have lost power to my servers several times (due to user pulling our the power plug)and the motherboard controllers always forced a re-sync every time while there were no issues or health change using the controller card. Certainly if you want to use RAID 10 then by all means you should, however you should quantify your statement as the main difference is in performance and the ability to loose multiple drives at the same time. For "most" home servers applications (with a backup strategy) and with the assumption that you have a backup drive available, single drive loss is more protection than what we had before. Secondly I average 230 Megs/sec write and 365 Read which rivals SSD performance. As I am going across a 1 gig connection, doubling that (assuming it was double) would not help at all unless I was severing multiple sources across multiple connections. There is no doubt that RAID 10 is better than RAID 5 but the cost in terms having to use extra drives makes it a bit prohibitive in the average use case not to mention the size of the case itself. The article you are referencing implies a mission critical application such as a business because of downtime and does not really apply to the average case. Not that the data is not as important but rather home servers have the luxury that they can be shut down and the drives replaced. No raid configuration can replace a good backup strategy not even RAID 10, but for the person who can shut there server down, and replace a drive when it goes bad, RAID 5 is a great solution. I would suggest you do a bit more experimenting and research with the "right" components and see if you still feel the same. Making a judgement/decision on the basis of built controllers may not be fair and from the setups I have done can tell you that even RAID 10 will be a hassle using MB controllers. A user is better off buying a controller card and going with a RAID 5 and a backup solution, than using the built in controllers under RAID 10. This is of course my opinion and I am basing this on the experimentation that I have done.

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My system holds five drives and one eSATA. One drive is the system drive and is backed up using WHS 2011 Server Backup. This is where all of my critical data is located. All my videos are on the RAID 5 drive. Soon to be a RAID 10 drive. There will be no more long wait times due to migration parity rebuilds and verifys due to blue screens or power failures. Read and write speeds will increase. Drives are cheap enough that it's worth it to add an extra drive than deal with the hassles of RAID 5. I'll let you know how the RAID 10 setup goes if the migration ever finishes. Quality RAID 5 add-in cards are too expensive for me. This is a Home Server. Cost should be kept to a minimum.

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My system holds five drives and one eSATA. One drive is the system drive and is backed up using WHS 2011 Server Backup. This is where all of my critical data is located. All my videos are on the RAID 5 drive. Soon to be a RAID 10 drive. There will be no more long wait times due to migration parity rebuilds and verifys due to blue screens or power failures. Read and write speeds will increase. Drives are cheap enough that it's worth it to add an extra drive than deal with the hassles of RAID 5. I'll let you know how the RAID 10 setup goes if the migration ever finishes. Quality RAID 5 add-in cards are too expensive for me. This is a Home Server. Cost should be kept to a minimum.

 

May ask questions and comment?

 

  1. I would be more concerned with the amount of BSODs and Power faults. Fix this first as RAID10 isn't going to solve those issues.
  2. Quality RAID5 cards (assuming you mean with on board RAM and BBU) can be had for fairly cheap you just need to know what to look for.
  3. Also using an addin RAID controller card takes load off the cpu, which may very well be the root fo your issues to begin with.
  4. While HDDs are cheap I would also argue that the cost of doubling the storage could very well be more than a "quality" RAID5 add in card. Not to mention the increase in operating costs.
  5. I've run a RAID10 as a home setup and let me tell you it just as much of a hassle as RAID5.
  6. Yes this is a home server , but no different than any other machine. Cost should be kept as low as the value of your data warrants.

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