[Btrfs-devel] Crash with reusing fs; on big volumes

Jan Engelhardt jengelh at computergmbh.de
Sun Jan 20 17:10:25 PST 2008

On Jan 20 2008 19:26, Chris mason wrote:
>Sorry, I'm a little confused on the test case.  Since this is i386,
>could we try again with values that are all below 16TB?  Also, could
>I get an exact list of steps to reproduce?

1. Get ahold of VMware Workstation 6.

2. Create as many 950 GB sparse virtual disks as you need. Maximum is
currently 60 SCSI disks and 4 IDE disks per VM. If more vaporware
storage is needed, use nbd^W openiscsid to make the space available
as block devices in one central VM.

3. Combine into a RAID array (linear or level 0); less than 16 TB.
# mdadm -C /dev/md0 -l linear -n 11 /dev/sd[b-l]
# fdisk -l /dev/md0
Disk /dev/md0: 11220.6 GB, 11220601339904 bytes

4. Create filesystem
# mkfs.btrfs /dev/md0
fs created on /dev/md0 nodesize 16384 leafsize 16384 sectorsize 4096
bytes 11220601339904

It seems like I hit it early this time - the (virtual) disks were
blank this time.

5. Mount
# mount -t btrfs /dev/md0 /mnt
Segmentation fault

6. Profit??

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