# What causes multiply-claimed blocks?

## TinheadNed

My 160Gb SATA drive has a single ext3 partition on it, and I am currently fscking it every chance I get, and every time, the following is returned:

```
Running additional passes to resolve blocks claimed by more than one inode...

Pass 1B: Rescanning for multiply-claimed blocks

Multiply-claimed block(s) in inode 49166: 21837026 21837027 21852195

Multiply-claimed block(s) in inode 49220: 12113955

Multiply-claimed block(s) in inode 49262: 12113955 12208419 21837026 21837027 21852195

Multiply-claimed block(s) in inode 4227080: 12208419

Pass 1C: Scanning directories for inodes with multiply-claimed blocks

Pass 1D: Reconciling multiply-claimed blocks

(There are 4 inodes containing multiply-claimed blocks.)

File /pub/myth/2002_20070102205300.mpg (inode #49166, mod time Tue Jan  2 22:29:57 2007)

  has 3 multiply-claimed block(s), shared with 1 file(s):

        /somefile (inode #49262, mod time Fri Jan 26 13:51:47 2007)

Clone multiply-claimed blocks<y>? yes

```

The /somefile is a dd from /dev/zero to generate the error.

The machine is a 1.3GHz duron, with a PCI SIL7113 SATA card.

Clues?

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## NeddySeagoon

TinheadNed,

Multiply claimed blocks are where the same disk block is reported to be owned by several files.

I see you are using ext3. Would you be using kernel 2.6.19 too ?

It had a nasty race condition which had been show to corrupt ext3 for some users.  It has been fixed now but I don't know which gentoo-sources the fix got into.

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## TinheadNed

I was wondering if it was the kernel.  I'm running 2.6.19-gentoo-r3 at the moment, which I thought had the fix in it.  Annoyingly, the machine was up for so long before that, I don't have the kernel for it.  But it wouldn't have been a race-problem, the disc isn't frequently used.

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## TinheadNed

Also, my PATA partitions are fine.

And the drive passes its extended offline SMART tests.  I'm suspecting the SATA controller.

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## TinheadNed

Well, I tried swapping the sata controller for a different one (still a sil3112) and it produced nasty nasty errors on the drive when trying to rsync data across, so I've gone back to my old 'multiply claimed blocks' one.

Still don't know what's causing this.

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