Re: Fail to assemble raid4 with replaced disk

[Wols Lists <antlists@youngman.org.uk>]

On 27/10/16 15:11, Santiago DIEZ wrote:
> Hi,
> 
> Indeed, here is what I had in terms of event count:
> /dev/sda10: 81589
> /dev/sdb10: 81626
> /dev/sdc10: 81589
> 
> Then the following procedure worked quite straightforward:
> --------------------------------------------------------------------------------
> # mdadm --assemble /dev/md10 --verbose --force /dev/sda10 /dev/sdb10 /dev/sdc10
> # mdadm --manage /dev/md10 --add /dev/sdd10
> --------------------------------------------------------------------------------
> 
> And 6h+ later:
> --------------------------------------------------------------------------------
> # cat /proc/mdstat
> Personalities : [raid1] [raid6] [raid5] [raid4]
> md10 : active raid5 sdd10[3] sda10[0] sdc10[2] sdb10[1]
>       5778741888 blocks level 5, 64k chunk, algorithm 2 [4/4] [UUUU]
> --------------------------------------------------------------------------------
> 
> Then I ran:
> --------------------------------------------------------------------------------
> # e2fsck -f -n -t -v /dev/md10
> e2fsck 1.42.5 (29-Jul-2012)
> Pass 1: Checking inodes, blocks, and sizes
> Pass 2: Checking directory structure
> Pass 3: Checking directory connectivity
> Pass 4: Checking reference counts
> Pass 5: Checking group summary information
> 
>     15675837 inodes used (4.34%, out of 361177088)
>       188798 non-contiguous files (1.2%)
>        14751 non-contiguous directories (0.1%)
>              # of inodes with ind/dind/tind blocks: 0/0/0
>              Extent depth histogram: 15626455/47037/15
>   1281308341 blocks used (88.69%, out of 1444685472)
>            0 bad blocks
>          101 large files
> 
>     15311457 regular files
>       361754 directories
>            0 character device files
>            0 block device files
>            0 fifos
>            0 links
>         2607 symbolic links (2310 fast symbolic links)
>           10 sockets
> ------------
>     15675828 files
> Memory used: 50976k/1912k (20541k/30436k), time: 1304.00/334.06/ 8.00
> I/O read: 4891MB, write: 0MB, rate: 3.75MB/s
> --------------------------------------------------------------------------------
> 
> Does it look OK enough to launch the mount?
> 
sorry - I've been away for the weekend - daughter's wedding :-)

But yes, that looks great. No errors on fsck either, I think :-)

I think your array looks fine. Just look at the output from smartctl for
your old drives and make sure that it doesn't look like another drive is
going to fail soon. I'm not quite sure what to look for, mostly bad
blocks and relocates, I think, but if you compare it with your new drive
and stuff looks dodgy, you can always ask for help.

Cheers,
Wol