Unable to recover hammer volume.

jscottkasten at yahoo.com jscottkasten at yahoo.com
Mon Jan 16 06:27:15 PST 2017

----- Original Message -----
From: Tomohiro Kusumi <kusumi.tomohiro at gmail.com>

>hammer_btree_extract: CRC DATA @ 9000000a4a1f3280/128 FAILED

Yes, I have this, and "critical error" reading inodes.

>This means bunch of inodes in certain sectors nearby were somehow
>corrupted. These are often found only when those inodes are read the
>next time after corruption, thus doesn't necessary affect booting
>unless those inodes are read on booting.

Yes, this is a backup volume.

>Onboot recovery really has nothing to do with random broken sectors
>where undo fifo is not involved, nor is it a problem of filesystems in
>general including hammer1. Also note that "recovery" here doesn't mean
>hammer1 somehow magically fixes user data. It means the filesystem
>keeps consistency of itself.

I would be happy to just delete them somehow.  I can rsync any incomplete data easily enough.

>Having said that, hammer1 could give an option for users to at least
>do whatever they want to do on a broken fs. It currently forces
>readonly mount, kernel panic, etc.

And there in lies the problem.  The forced read only mount prevents me from doing anything to fix it...  :-(

I just did check the mount_hammer page to see if there were any useful options, but nothing unfortunately.


2017-01-16 22:52 GMT+09:00 PeerCorps Trust Fund <ipc at peercorpstrust.org>:
> Hi,
> It sounds pretty much like its supposed to operate if your file system tree
> is potentially corrupted somehow. You may very well need to copy off the
> data and recreate the file system. Unless of course the underlying block
> storage has some issues (bad sectors etc.).
> I do recall there not yet being a way to gracefully fix a "broken" HAMMER
> file system.
> Perhaps I am wrong and someone else will offer more enlightened feedback.
> Out of curiosity when the file system was mounted at boot, did it not fail
> to mount? It seems like it should have been brought back to a consistent
> state after your reboot.
> Mike
> On 01/16/2017 03:32 PM, jscottkasten at yahoo.com wrote:
>> Hi guys,
>> I've tried searching the answer for this, but cannot find any proper
>> discussion on the topic.
>> I have a hammer volume that had to be forced into an unclean shutdown.
>> There are some files and/or folders that now have CRC errors.  When the
>> damaged data is encountered, it causes hammer to report a critical error and
>> remount the file system as READ ONLY.  Thus, I am unable to delete or remove
>> the bad data in any way to recover the file system to an operable state.
>> Is there some tool that I should run on the file system to do this???  I
>> know the bad data is restricted to a small number of folders.  Would love to
>> somehow purge it so the volume can be returned to normal operation.  It's a
>> 2TB volume, so I'm hoping I don't have to reformat and re-create the volume.
>> Thanks for any advice.
>> Regards,
>> -J. Scott Kasten-

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