partman: mkfs.xfs: error - cannot set blocksize 512 on block device /dev/dasda1: Invalid argument

Default Comment by Bridge

Default Comment by Bridge

Default Comment by Bridge

------- Comment From <email address hidden> 2016-02-11 09:53 EDT-------
The DASD device does not accept block sizes that are smaller than the block size with which the DASD has been low-level formatted. That means that for a 4K low-level format, you have to use 4K block size of the file system at a minimum.

------- Comment From <email address hidden> 2016-02-11 10:14 EDT-------
partman uses obviously and erroneously a method with 512 byte block size (like on SCSI disks) to create an xfs filesystem. This method needs to be adjusted for ECKD DASDs, since they have usually a block size of 4096 bytes. (In very rare cases, DASDs can be dasdformatted with 2048 or 1024 or 512 bytes blocksize, but it doesn't make sense and wastes space.)
I didn't have a look into the partman code, but it looks like the libparted underneath uses a default blocksize for xfs of 512 where it should use 4096 (for ECKD DASDs, not for SCSI LUNs!). But that's just an assumption.

Parted is not used to create xfs filesystem. The call chain is d-i -> partman -> partman-xfs -> mkfs.xfs, thus xfsprogs is used.

It defaults to XFS_DFL_BLOCKSIZE_LOG 12, that is 2**12 = 4096, i.e. 4k block size.

Looking at the syslog, however, it shows that BLKBSZSET ioctl is called with 512 value...

Digging further, there are two code paths in mkfs.xfs, one with blkid probes and another one without, which simply uses hard-coded 512 value. Checking xfsprogs build-log it appears that d-i version of mkfs.xfs is built without blkid support

"""
    [CC] xfs_mkfs.o
gcc -g -O2 -Os -DNDEBUG -DVERSION=\"4.3.0\" -DLOCALEDIR=\"/usr/share/locale\" -DPACKAGE=\"xfsprogs\" -I../include -I../libxfs -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -funsigned-char -fno-strict-aliasing -Wall -DHAVE_MNTENT -c xfs_mkfs.c
xfs_mkfs.c:465:4: warning: #warning BLKID is disabled, so signature detection and block device access are not working! [-Wcpp]
 # warning BLKID is disabled, so signature detection and block device\
    ^
    [LD] mkfs.xfs
"""

I think two things should happen. In non-blkid case xfs is really ought to default to 4096, as per manpages.
And secondly, d-i built should come with blkid support enabled on Ubuntu, as really, anything else is not acceptable.

11542# Check whether --enable-blkid was given.
11543if test "${enable_blkid+set}" = set; then :
11544 enableval=$enable_blkid;
11545else
11546 enable_blkid=yes
11547fi

looks like autoconf is buggy, and if one specifies --enable-blkid, or enable-blkid=yes (as done in debian/rules) the net effect is to _disable_ blkid support...

This bug was fixed in the package xfsprogs - 4.3.0+nmu1ubuntu1

---------------
xfsprogs (4.3.0+nmu1ubuntu1) xenial; urgency=medium

  * Enable blkid in d-i, by dropping explicitly passed configure option
    (broken configure). (LP: #1544574).
  * Drop trying to create upstream distribution.

 -- Dimitri John Ledkov <email address hidden> Tue, 16 Feb 2016 00:20:02 +0000

------- Comment From <email address hidden> 2016-02-25 08:22 EDT-------
successfully verified with version 4.3.0+nmu1ubuntu1.