Re: LVM and XFS cannot set blocksize on block device

[Rene Salmon <rsalmon@xxxxxxxxxx>]

Hi,


Thanks for the replies.  The block size of my LV is indeed 4096

helix-priv:~ # blockdev --getbsz /dev/vg_u00/lv_u00
4096

I can mount and use the xfs file system no problems.  I have even tested
extending the LV and doing an xfs_grow and that seemed to work no 
problems.  So I take it I can safely ignore the warning.

Should I report this as a bug?  If so Can someone point me to the 
bugzilla page or something of the sorts?

Thanks
Rene



Shailendra Tripathi wrote:
> > > Thanks for the reply. The "-s size=4096" helped I was able to create
> > > the file system, then mount it and use it.  I did however get a
> > > warning still about "cannot set blocksize on block device".
>
> > I don't know much about the LVM code, my guess is that
> > ioctl(... ,BLKBSZSET, ...) is failing, strace would confirm this.
>
>
> libxfs_device_open () seems to be working with the pre-conceived notion 
> of assuming block devices of only 512 bytes in size.
>
> if (!readonly && setblksize && (statb.st_mode & S_IFMT) == S_IFBLK)
>    platform_set_blocksize(fd, path, statb.st_rdev, 512);
>
> This eventually calls to set the blk sz to 512. Since, your volume does 
> not support less than 4k, it returns EINVAL. I think, libxfs_init should 
> be modified to take pass on the -s size option to this call so that it 
> does not happen.
>      However, I don't see any problem despite this failure. Everything 
> else should work fine.
>
>
>
>
> > > Everything seems to be working but I am a bit worried about the
> > > warning message.  Following is the message.  Any ideas if it is safe
> > > to ignore this or any way to get rid of it?
> >
> >
> > What does:
> >
> >   blockdev --getbsz /dev/vg_u00/lv_u00
> >
> > say?
> >
> >
> > If mkfs.xfs is trying to set a blocksize that already matches the
> > underlying device, it woudn't be hard to silence the warning by doing
> > a check before unconditionally setting it, though I don't know that
> > it's worth it.

--
-
--
        Rene Salmon
        Tulane University
        Center for Computational Science
        http://www.ccs.tulane.edu
        rsalmon@xxxxxxxxxx
        Tel 504-862-8393
        Tel 504-988-8552
        Fax 504-862-8392