Re: librbd: error finding header

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 13/07/12 01:30, Tommi Virtanen wrote:
On Wed, Jul 11, 2012 at 9:41 PM, Josh Durgin <josh.durgin@xxxxxxxxxxx> wrote:
You're right about the object name - you can get its offset in the
image that way. Since rbd is thin-provisioned, however, the highest
index object might not be the highest possible object. When you first
create an image, only the header object is created.
You can re-create it with a size that's known to be greater than the
old size (put in a terabyte extra, or something), and then use a
partitioning tool to see what the disk layout really is, and resize
based on that.
Good point. However ceph should not be aware of image internal structure. In most installations image would contain partition table which obviously may be used to calculate image size but in some cases (when whole image is used for something) it may not be. Perhaps good point for RBD would be to create first and last object for image when RBD header is created. Will waste a bit of space but generally these objects will hold partitioning information and just their existence would allow to establish boundaries of the image. Does not help with snapshots though. But definitely will be helpful for a recovery tool.

--
To unsubscribe from this list: send the line "unsubscribe ceph-devel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Index of Archives]     [CEPH Users]     [Ceph Large]     [Information on CEPH]     [Linux BTRFS]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]
  Powered by Linux