On Sunday April 23, dislessico@xxxxxxxxx wrote:
> Hi all,
> to make a long story very very shorty:
> a) I create /dev/md1, kernel latest rc-2-git4 and mdadm-2.4.1.tgz,
> with this command:
> /root/mdadm -Cv /dev/.static/dev/.static/dev/.static/dev/md1 \
> --bitmap-chunk=1024 --chunk=256 --assume-clean --bitmap=internal \
^^^^^^^^^^^^^^
> -l5 -n5 /dev/hda2 /dev/hdb2 /dev/hde2 /dev/hdf2 missing
>
From the man page:
--assume-clean
Tell mdadm that the array pre-existed and is known to be clean.
It can be useful when trying to recover from a major failure as
you can be sure that no data will be affected unless you actu-
ally write to the array. It can also be used when creating a
RAID1 or RAID10 if you want to avoid the initial resync, however
this practice - while normally safe - is not recommended. Use
^^^
this ony if you really know what you are doing.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
So presumably you know what you are doing, and I wonder why you bother
to ask us :-)
Ofcourse, if you don't know what you are doing, then I suggest
dropping the --assume-clean.
In correct use of this flag can lead to data corruption. This is
particularly true if your array goes degraded, but is also true while
your array isn't degraded. In this case it is (I think) very unusual
and may not be the cause of your corruption, but you should avoid
using the flag anyway.
> b) dm-encrypt /dev/md1
>
> c) create fs with:
> mkfs.ext3 -O dir_index -L 'tritone' -i 256000 /dev/mapper/raidone
>
> d) export it via nfs (mounting /dev/mapper/raidone as ext2)
^^^^
Why not ext3?
>
> e) start to cp-ing files
>
> f) after 1 TB of written data, with no problem/warning, one of the
> not-in-raid-array HD freeze
This could signal a bad controller. If it does, then you cannot trust
any drives.
NeilBrown
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