linux raid5 problem

Discussions on using the professional data recovery program R-STUDIO for RAID re-construction, NAS recovery, and recovery of various disk and volume managers: Windows storage spaces, Apple volumes, and Linux Logical Volume Manager.
scanray
Posts: 6
Joined: Thu Feb 23, 2012 8:14 am

linux raid5 problem

Post by scanray » Sun Mar 11, 2012 10:24 pm

Hi,

I had a raid5 in mandriva 2010.2: 5x1TB
It worked very well until the MB is failure. Change the MB, I installed again MDV2020.2 after installed and all updates, I connected the 5HD of the raid. I rebooted the computer and all good. I mounted the raid to copy some configuration files, copied them and rebooted the computer. Upon restart, I noticed with surprise that the raid was rebuilt. Let him finish, no way. When he finished and I wanted to mount the raid, came the message: no partition table. @ # @ $ ^%

Reviewing the configuration and log, I found that initially the system had recognized the HDs as part of a raid in this order: cbdef. After restarting were: bcdef. @ # $% Do not know why.

At this point, I stopped him again raid and assembled with the HD in the original order. When finished rebuild mdadm I tried to mount the raid and left the message: no format the partition.

In another computer I have installed virtualbox. In a Linux, I have recreated the raid5, I have generated several files of different sizes and then I generated the same disc replacement happened to me on the computer. I've even created a complete mess of the discs, not just 2. Always, when returning to the original setting, my files are listed and the correct cheksun. (created with md5sum)

After this: google -> r-studio
I assembled the raid in different forms, scanned, reviewed, etc..
Apparently, the raid had created it with a chunk = 64k. When I came back to arm did not put this value, so he put the mdadm default = 512k.
I assume that this was a mistake but I'm not sure. Anyway, my intention is to recover my files.

I need help with:

1) Which version is better: The windows or linux? I will use locally.
2 When I bought the license, I can use it in win and lin? or different license?
3) In the scan, r-studio has found several files. These are listed in different colors. What does it mean? There are green, orange, red.
4) has found most of the files, but some of these are within the inode item with a red cross, I mean I can not recover?
5 I have found a tutorial on how to detect the order of the disks. The problem is that is ntfs. Anyone know how to do ext4?
and also how to find the original values​​?

Thanks for the help you can give me

Alt
Site Moderator
Posts: 2271
Joined: Tue Nov 11, 2008 2:13 pm
Contact:

Re: linux raid5 problem

Post by Alt » Mon Mar 12, 2012 2:53 am

1. The windows version is a little bit ahead of its Linux counterpart.
2. Windows, Linux, or Mac are different versions, but this is about the host OS on which the program is to run. Any version supports all supported files systems. That is, if you use the Windows version, you'll be able to recover files from with NTFS, HFS, extFS, etc, disks. The same is for the Linux and Mac versions.
3. Those aren't files, those are recognised partitions, that is, partitions that R-Studio believes reside or resided on the disk. The color shows how much info on this partition remains on the disk. See more on R-Studio on-line help: Disk Scan, on the bottom.
4. A red cross means that the file has been normally deleted. It may be recovered.
5. It looks like ext4 is a problem for this matter.

scanray
Posts: 6
Joined: Thu Feb 23, 2012 8:14 am

Re: linux raid5 problem

Post by scanray » Wed Mar 14, 2012 10:40 pm

Hi Alt,

Excuse the delay in responding, I was doing some tests.

What you did not answer, was if it is possible to use RStudio license for windows in linux version

In tests I have done in RStudio, I have found results that confuse me, and has led me to error, possibly: RStudio detected disks in reverse order. First list the last and then list the first.

1) The last disk to appear is called SoftRAID1. This is the raid5 detected by the system. When I make a scan to it, appears "Recognized", then I say show me the files found. Root appears here and the complete structure of the raid. All files are in good condition.
2) after realizing the order of the disks, I've re-created a BlockRaid5 with the correct order of disks. I have tried almost all parameters. Never shows the correct structure of raid5 with files.

And, examining the disks rom raid I have this:

Code: Select all

/dev/sdb1:
    Data Offset : 1024 sectors
   Super Offset : 8 sectors
   Device Role : Active device 0
Is the same in all disks. How can I put this data into rstudio ? I have see only one offset data in the block raid created. This offset is "Super Offet" or "Data Offset" from the originals ?


Back to ask, is anything special I should do to assemble the raid5 in r-studio?

Thanks for the help and patience.

Alt
Site Moderator
Posts: 2271
Joined: Tue Nov 11, 2008 2:13 pm
Contact:

Re: linux raid5 problem

Post by Alt » Fri Mar 16, 2012 8:00 am

You need to enter 1024 sectors to the offset of the disks in the RAID parents tab, Super offset is the offset on the disks of the RAID, not its file system.

scanray
Posts: 6
Joined: Thu Feb 23, 2012 8:14 am

Re: linux raid5 problem

Post by scanray » Fri Mar 16, 2012 4:48 pm

Hi,

It does not work.

When I do a scan to Block Raid with default values​​, except that change BlockSize 512k, appears all but some corrupted files. When I change the offset to any other value, disappears "Direct Volume" that is displayed when I assembled the BlockRaid, performed a scan but nothing appears.

thanks

Alt
Site Moderator
Posts: 2271
Joined: Tue Nov 11, 2008 2:13 pm
Contact:

Re: linux raid5 problem

Post by Alt » Sat Mar 17, 2012 2:36 am

Try to create regions starting from Sector 1024 on the disk and create a RAID out of them. You don't have to scan the entire raid to find partitions on it, only first 5 GB would be enough.

scanray
Posts: 6
Joined: Thu Feb 23, 2012 8:14 am

Re: linux raid5 problem

Post by scanray » Sat Mar 17, 2012 8:04 pm

I'm testing with a raid5 of 1GBx5 = 4GB. No Problem scaning all the raid.

Using offset=1024 dont work. Wen I scan with this value, when I scan with this value, and when I open Recognized0 to view the files, appears Root and is full of $inodes, with a red cross. No dirs, no files.

thanks

Alt
Site Moderator
Posts: 2271
Joined: Tue Nov 11, 2008 2:13 pm
Contact:

Re: linux raid5 problem

Post by Alt » Tue Mar 20, 2012 3:16 am

And creating a RAID out of the regions that started from Sector 1024?

scanray
Posts: 6
Joined: Thu Feb 23, 2012 8:14 am

Re: linux raid5 problem

Post by scanray » Tue Mar 20, 2012 11:44 pm

What I want to find out, is why the files are corrupt.
Considering that the raid5 is fine, and that the files go corrupt, let me doubt if files in raid5 in poor condition, they are really bad or is it a configuration problem with RStudio.

thanks

Alt
Site Moderator
Posts: 2271
Joined: Tue Nov 11, 2008 2:13 pm
Contact:

Re: linux raid5 problem

Post by Alt » Wed Mar 21, 2012 3:10 am

The files may be corrupted because something was written to the disk during array rebuild or because the RAID parameters are incorrect. It's hard to say without seeing actual data on the disks.

Post Reply