[sheepdog] [PATCH v1] sheep/md: leave cluster if disk number equals zero in handling EIO
sirio81 at gmail.com
Thu Sep 18 10:45:43 CEST 2014
2014-09-18 9:04 GMT+02:00 Hitoshi Mitake <mitake.hitoshi at lab.ntt.co.jp>:
> Thanks for your reporting. BTW, I don't like the current way of
> handling -EIO (not limited to md, and not works well
> currently). Because if sheep has no disks, it means it cannot store
> log. It will make trouble shooting almost impossible. Rather than
> calling leave_cluster(), simply calling panic() or exit() would be
> enough. How do you think, Valerio and Bingpeng?
I was considering this scenario:
being /mnt/sheep/0 the mount point of a different device.
In such case, it's always safe to unplug a disk (logs and metadata are
Metadata dir should never be on the same device where objects are stored.
IMHO, instead of a 'good practise', this should be forced requiring at
least 2 folders in sheep syntax (and even better checking by 'stat'
that they are not on the same device).
 it may be the same physical disk, but another partition.
In the case of
it's right to exit the cluster, because we have a single device and
it's giving EIO.
Metadata and log may have problem being written, so better exiting the cluster.
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