Checksum Error on SD card repair?

[Angus]

Using my 1200 Pistorm this morning I got a requester appear with the worrying message:


SDH0: has a checksum error on disk block 1478925




Am I right in thinking any Amiga repair software is not going to be equipped to fix an SD card? Things like Quarter master tools - or HDTools configured for SD?


Thanks for any advice.

[Daedalus]

It depends on the drive/partition setup really, and not the underlying technology. Most tools won't work above the 4GB point on the drive, so if it's a partition fully within the first 4GB you should be able to use most tools. For more modern drives, there's a version of DiskDoctor included with OS 3.2 that can handle FFS partitions above 4GB.

What might be pertinent though is to understand why it happened. It might be a corrupted file from a write operation that was interrupted, or it could be an indication of some hardware issue. It might make sense to take an image of the card at this point in case it deteriorates, and use any recovery tools on the image instead.

[derSammler]

The Amiga has no idea whether or not you are using an SD card. It's just a block device with a file system. Any tool will work as good (or bad) as with a real hard disk.

However, any tool that does lots of write operations during repair might actually kill the SD card, as those are not made for bulk writes.

I would image the card, repair it in WinUAE, and write the repaired image back to the card. This way, you also have a backup if the repair fails.

[alexh]

It really depends of the filesystem. DiskDoctor for FFS or there is a tool for PFS3 too.

At least it's not the dreaded "disk is invalidated, have to re-validate" which used to take forever

I think PFS3 is a journaled file system? That makes it more difficult to get checksum errors.

[Angus]

Hi guys,

Thanks so much for the responses.

It's my boot partition which I kept as FFS.

I haven't used Disk Doctor since I messed up some floppies with it in probably the late eighties. I'm sure it's very good, but I'm a bit concerned it maybe designed for people who are more clued up than me.

I had a look at it with HDToolBox but the only error checking thing I found wouldn't offer anything useful that I could see.... so I ran an Analyse Repair scan with Quaterback Tools and found the following 2 files with problems:

FileX-68K checksum error - file will be recalculated

Mod1OutrunMSS checksum error - file will be recalculated (music file from Outrun port, I think)

Because I skipped them I can't check the bitmap.

Can I safely select repair instead of skipping them and then repair the bitmap if it needs it.



P.S. I have fairly recent backups of the card on separate cards so this is (hopefully) not a major drama. For now, I'd like to see if I can fix the card in the 1200 and see how it goes from there.

Vaguely connected:
When I installed the Cannonball Outrun port some months back, I could NOT get the Amiga .mods to play with it. I seem to remember something about corrupted files in the roms at the time..... I wonder if this is why I got no music. :-/

[Daedalus]

Well, the checksum being wrong means that the file has been modified in some way, and more than likely that modification hasn't been completed. So there's no real harm in trying it because chances are the files are damaged anyway, so if you can recover them it's a bonus. Fixing the checksums shouldn't affect any other files either so even if the files are damaged you can get your volume revalidated and copy back those files from your backups.

[Angus]

Originally Posted by Daedalus

Well, the checksum being wrong means that the file has been modified in some way, and more than likely that modification hasn't been completed. So there's no real harm in trying it because chances are the files are damaged anyway, so if you can recover them it's a bonus. Fixing the checksums shouldn't affect any other files either so even if the files are damaged you can get your volume revalidated and copy back those files from your backups.

Okay, I allowed Quarterback Tools to fix things, and it ended up saying:


Volume is Useable. Never a hugely inspiring expression.


I cycled through it again, and "Useable" got promoted to "Good".


I'll obviously keep an eye on it, hopefully it was just some issue with those 2 files. (fingers crossed). Thanks guys.

[FOL]

I found FFS in 3.2 kept currupting my sd every couple of boots. Ended up using pfs3 and never had another issue.

Originally Posted by Angus

Okay, I allowed Quarterback Tools to fix things, and it ended up saying:


Volume is Useable. Never a hugely inspiring expression.


I cycled through it again, and "Useable" got promoted to "Good".


I'll obviously keep an eye on it, hopefully it was just some issue with those 2 files. (fingers crossed). Thanks guys.

[alexh]

I think that could be due to it being a non-journaled FS and having a write buffer? If you reset the Amiga before it has flushed the write buffers then you get corruption. But I may be wrong I am not 100% familiar with Amiga xFS.

[Angus]

Originally Posted by FOL

I found FFS in 3.2 kept currupting my sd every couple of boots. Ended up using pfs3 and never had another issue.

Well, my boot partition, SDH0: I thiought I would keep as FFS, all the rest are PFS3.


I'm on 3.1 by the way.

[thomas]

Originally Posted by Angus

Well, my boot partition, SDH0: I thiought I would keep as FFS, all the rest are PFS3.

That's a stupid decision. The boot partition benefits the most from the speed of PFS.

Also mixing file systems is strange. If you like PFS, use it everywhere. If you suspect it, don't use it at all. It does not make sense to mix.

[Angus]

Originally Posted by thomas

That's a stupid decision. The boot partition benefits the most from the speed of PFS.

Also mixing file systems is strange. If you like PFS, use it everywhere. If you suspect it, don't use it at all. It does not make sense to mix.

Everything okay, Thomas? That seemed unnecessarily rude. :-/ I'm very happy with the performance of my boot partition, and it seemed to me (perhaps wrongly) that with FFS residing in the rom, it might be a good thing for a recovery situation.

Since I got the PiStorm I've been trying out things like Quake 2 that I keep on the other partitions with similar things that really require a more capable system like PFS3. As for having more than one filesystem, why not? Was Jimi Hendrix "wrong", as a left handed guy, to play an inverted right hand Fender? Now there's a question.

As ever I'm grateful for your wisdom, but I'd appreciate it if you can keep it civil.

[thomas]

I apologise, it was not my intention to sound rude. I just wanted to point out the facts.

[Angus]

Originally Posted by thomas

I apologise, it was not my intention to sound rude. I just wanted to point out the facts.

No worries, Thomas.