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Mandriva 2008.1 File System


viking777
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This is why I am asking.

 

I use Acronis True Image to make disc images of all my OS's so that when I break them I can easily replace them with a working copy. (shock horror - I know it isn't open source, but as soon as an open source program arrives that is one tenth as good as Acronis I'll use it - promise :P ). Anyway Acronis will image just about anything, but it seems to be having trouble with 2008.1. Every time I make an image with it I get a warning about 'File system errors' and advice to error check the disk. I have error checked it a hundred times and there are no errors on it. It allows you to proceed with the image but goes on to say that it can only be done on a 'sector by sector' basis. This results in a much larger image because (I presume) it is imaging the free space as well as the data (which it normally doesn't do). This has a by product that if you wish to restore it you can only do so on a partiton of identical size whereas normally you can reinstall onto any partition that is big enough as it dynamically resizes while it restores. It still produces a perfectly good image and restoring from it is trouble free as well, but because the file size is larger it takes longer to complete both processes.

 

My original version of 2008.1 was an early testing version that I continually updated to its final iteration. Yesterday I found the bandwidth to download a final release version of 2008.1 and both versions display the same characteristics when used with my disc imaging software. I had initially assumed that the specific behaviour was perhaps because my original version was a testing version or that I had some kind of disc error on the partition where it was installed, but when my new version of 2008.1 displayed the same behaviour, it started me wondering why. The new version of 2008.1 is on my old Ubuntu partition, this has been imaged dozens of times without this error message so it really cannot be disc corruption, it must be something to do with the Mandriva file system - but what?

 

I also have a copy of 2008.0 and it images normally with no error messages as does Linux Mint and Ubuntu before I deleted it.

 

So if anybody has any ideas as to why this might be I would be interested to know.

 

I am sure it wouldn't make much difference but it is Mandriva One that I have installed.

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Chances are it's probably due to some parameters assigned for the ext3 partition when it was created. It would require some comparing to see what the differences are between one partition and another. There is probably a tool that can do this, but I've not googled to find out exactly what right now.

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I don't understand the technical details, but AIUI on 2008.1 ext3 default inode is 256 against 128 on previous versions. This also causes problems with trying to use Grub from previous versions to boot 2008.1. A search of bugzilla for "grub" should locate some of the discussions on the subject.

 

Jim

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Thanks very much for those replies people.

 

I have done a bit of reading around the problem and I seem to have come up with the conclusion that it is not possible to change the space per inode back to 128 without rewriting the file system and thus destroying the data.

 

Is this correct? If so I guess I will just have to live with this problem.

 

Edit. Still thinking about this. If you preformat the disk with the the inode size you want and then reinstall, is there an option in the installtion routine to bypass the formatting that it does? I have always just let it format the partition and thus have never noticed if you can stop it doing so.

Edited by viking777
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Yes, you can leave the filesystem as it is without formatting it again. So you could prepare the system first with the space per inode set correctly, then install, and have no problems. At least, providing of course that this is causing the problem, and not some other option.

 

Any data currently on these partitions would have to be copied off to another machine so that you could copy it back again later, unless of course there is nothing to keep on those partitions right now.

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Thanks Ian, that is just what I suspected, and as you said there is no guarantee that this is actually the problem. I won't do anything just now as I have spent a long time configuring 'spring' the way I like it and it is working very well now. I will wait until later in the year when I start testing cooker again and try it with that and see if it makes a difference.

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  • 1 month later...

Well, I have finally got around to investigating this and it seems that the bytes per inode problem is indeed what is causing Acronis to fail to image normally.

 

In order to check this I had to do a fresh install on a pre formatted partition and of course not allow the installer to format again. Once I had done this I then used True Image to see if it could image that partition normally, and indeed it can.

 

I used Acronis Disk Director to format the partition and it chose a default size of 8192 bytes per inode. I later booted from Disk Director again and had a look at the interface for changing the space per inode (Acronis can do just about anything). The minimum space per inode that it can recognise is 4096 bytes which seems an awful long way removed from the 256 bytes that Greg and jkerr mentioned earlier.

 

Anyway whatever the supposed benefits of setting it at that size I am sure that in my case they are massively outweighed by the inconvenience of not being able to use Acronis properly, so it looks like on every install from now on I am going to have to pre-format. I guess that will start when the first 2009 iso comes out as I intend to install that from scratch.

 

In the meantime though I will try and contact Acronis and see if they have any solution to it.

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I used Acronis Disk Director to format the partition and it chose a default size of 8192 bytes per inode. I later booted from Disk Director again and had a look at the interface for changing the space per inode (Acronis can do just about anything). The minimum space per inode that it can recognise is 4096 bytes which seems an awful long way removed from the 256 bytes that Greg and jkerr mentioned earlier.

 

Bytes per inode is not the same as inode size. See man mkfs.ext2.

 

Jim

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Thanks for pointing that out Jim, although I must admit I find it extremely difficult to get my head around the difference between the two.

 

Anyway the fact remains that if I preformat with Acronis then True Image works and if I don't preformat it still works but not properly.

 

I have emailed the Acronis tech support people to ask what they know about it. I'll let you know what they come up with. I suspect they will invite me to buy the Linux server version! No chance!

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Now I am very confused. I thought I had this sorted, as I said above I pre-formatted, installed and then imaged the disk and everything was fine, it worked normally. Now just 2 days later I tried another backup and it had gone back to the previous error message with the long backup time and the large file size. In the intervening 2 days all I have done is to update it which obviously can't change the space per inode size. So perhaps I was wrong and space per inode is not what is causing it. The Acronis interface suggests I have file system errors - well if I have then they are not ones that e2fsck can locate.

 

I have emailed Acronis support to see if they can suggest something, but since it now appears that the information I have given them is wrong it is not surprising that I have not had a reply yet.

 

In the meantime (in desperation) I have tried Clonezilla again. It does image it normally in about the same time that Acronis is taking with the error message (on 2008 which doesn't generate the error message the image is complete in less than half the time and the image size is also smaller than Clonezilla's). The problem with Clonezilla is the appalling interface (ok it is not quite as bad as partimage, but nearly) and the fact that it doesn't do incrementals.

 

So I don't really know what is happening now (not an unusual situation for me) but I would like to get to the bottom of it. Even more so, I would like someone in the Linux world to produce a sensible disk imaging program. I personally would even pay for one because disk images are one of the most important safeguards you can have in computing. When I think of the vast amount of resources that have been thrown at Beryl and Compiz and the like whilst absolute essentials like imaging have been left to dd and partimage it makes me want to :wall:

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  • 3 weeks later...
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Thanks for the info.

 

I had the same problem with fedora 9.

 

I followed your advice and installed fedora9 (e2fsprogs 1.40.8-3) on top of a filesystem created using gparted (0.3.4.11) with an inode size of 128. I was then able to backup using acronis true image.

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I am presuming that since these changes are being adopted by various distros - as there must be a reason for changing the inode size, and thus, Acronis will most likely update this for their newer versions. At least, something I would expect of a commercial product.

 

You shouldn't be forced at least to create your partitions exactly how Acronis want :)

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The change was done upstream in e2fsprogs. The reason is that ext4 will need minimum 256-byte inodes. If you have an ext3 partition with 256-byte inodes it will be possible to convert it into an ext4 partition without data loss (as you can do between ext2 and ext3), but it won't be possible to convert ext3 partitions with inodes smaller than 256 bytes into ext4 partitions.

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I am presuming that since these changes are being adopted by various distros - as there must be a reason for changing the inode size, and thus, Acronis will most likely update this for their newer versions. At least, something I would expect of a commercial product.

 

You shouldn't be forced at least to create your partitions exactly how Acronis want :)

 

Your expectations are absolutely correct ian, but the reality is a little different. In order to try and beat this problem I upgraded from True Image 9 to version 11. It has made no difference. It still images any Linux drive that I have, but it only does so on a sector by sector basis which means that it takes longer, gives a larger image size, and does not have the ability to resize a restore. As an experiment I created my latest 2008.1 install with a partition created by Acronis disk director and this partition it will image normally.

 

The point is though that I should not have to - and don't want to - use commercial disk imaging software, a satisfactory solution should exist for Linux, but it doesn't, at least not unless someone has produced something in the last 3 weeks which is how long ago I last tested the alternatives. (The last one I tested was Clonezilla - I did an image/restore on my old laptop. It trashed the drive I saved the image to, it trashed the drive I restored the image to and it trashed the bootloader as well - pretty effective eh? Now the point is that I have the knowledge and the tools to put right all these disasters, but an awful lot of people won't have.)

 

Backups and imaging are so so important to every computer user that a sensible imaging solution should be one of the first packages ever produced for any Linux distro but it never is, we always have to suffer the likes of dd and partimage or use commercial alternatives like Acronis which now no longer work.

 

As I said I would I contacted Acronis support to describe this problem and I even provided links to the e2fsprogs pages describing the changes to the filesystem that Greg2 gave me. As I expected the reply I received was a link to their 700 dollar/pound server product for Linux.

 

I fully realise that I have no right to criticise anyone since I have never written a single line of computer code in my life and almost certainly never will, I was just born a bit too early to have the chance to do that. But at the risk of sounding like the proverbial worn out gramophone record, I will repeat that all the vast resources that have been thrown at Beryl/Compiz and now the same resources that are being thrown at the Vista clone - KDE4, would be vastly better spent on providing the absolute basics that are required for any operating system and a satisfactory imaging solution most definitely comes into that category.

 

Please forgive my cynicism.

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