[CentOS] EXT4 mount issue

Steve Brooks steveb at mcs.st-and.ac.uk
Mon Oct 4 17:52:45 EDT 2010


Hi Miguel,

Thanks for the reply.

> "What people are saying"? So instead of understanding and solving some issue

I was just a little worried at the response from Brent earlier quote 
"Don't play Russian Roulette and use ext4."  . The really odd thing here 
is that on another raid disk created the "exact" same way with the exact 
same parameters to "mkfs" and identically mounted I have an EXT4 
filesystem with different attributes, see below. Surely that should not 
happen. Also as I understand it one of the defaults is to have "journal" 
enabled not disabled.

[root at vraid3 ~]# tune4fs -l /dev/sdc
tune4fs 1.41.9 (22-Aug-2009)
Filesystem volume name:   <none>
Last mounted on:          /vraid3/vraid3
Filesystem UUID:          9e1d0cbf-f5f8-4116-9b60-a9e3c07da220
Filesystem magic number:  0xEF53
Filesystem revision #:    1 (dynamic)
Filesystem features:      has_journal ext_attr resize_inode dir_index 
filetype needs_recovery extent flex_bg sparse_super large_file huge_file 
uninit_bg dir_nlink extra_isize
Filesystem flags:         signed_directory_hash
Default mount options:    (none)
Filesystem state:         clean
Errors behavior:          Continue
Filesystem OS type:       Linux
Inode count:              609484800
Block count:              2437935360
Reserved block count:     121896768
Free blocks:              2107056555
Free inodes:              609318938
First block:              0
Block size:               4096
Fragment size:            4096
Reserved GDT blocks:      442
Blocks per group:         32768
Fragments per group:      32768
Inodes per group:         8192
Inode blocks per group:   512
Flex block group size:    16
Filesystem created:       Mon Jan 18 19:16:27 2010
Last mount time:          Fri Oct  1 19:38:31 2010
Last write time:          Fri Oct  1 19:38:31 2010
Mount count:              1
Maximum mount count:      28
Last checked:             Fri Oct  1 18:50:37 2010
Check interval:           15552000 (6 months)
Next check after:         Wed Mar 30 18:50:37 2011
Lifetime writes:          146 GB
Reserved blocks uid:      0 (user root)
Reserved blocks gid:      0 (group root)
First inode:              11
Inode size:               256
Required extra isize:     28
Desired extra isize:      28
Journal inode:            8
Default directory hash:   half_md4
Directory Hash Seed:      820f990d-9af5-4fb3-9e58-1c4bd504ca12
Journal backup:           inode blocks





On Mon, 4 Oct 2010, Miguel Medalha wrote:

>
>>  Below is the output from "tune4fs". From what people are saying it looks
>>  like et4 may not be the way to go.
>> 
>
> "What people are saying"? So instead of understanding and solving some issue 
> you just jump wagon, maybe only to find some other issue there?
>
> ext4 is stable and works perfectly. You just have to configure it properly, 
> as with anything.
>
> Can you still recreate the filesystems? If so, study the parameters for ext4 
> and use them. You will want "extents", because it provides a much better use 
> of disk space and avoids fragmentation.
>
> As you are, you can still create a journal on the filesystem you have, using 
> tune4fs. Look under switch -o (options).
>
> As an example, I give you some of what I have here with a ext4 partition:
>
> In /etc/fstab:
>
> LABEL=/data1            /data                   ext4 
> defaults,data=journal,acl,user_xattr 1 2
>
> tune2fs gives me the following:
>
> Filesystem features:      has_journal ext_attr resize_inode dir_index 
> filetype needs_recovery extent flex_bg sparse_super large_file huge_file 
> uninit_bg dir_nlink extra_isize
> Filesystem flags:         signed_directory_hash
> Default mount options:    journal_data user_xattr acl
>
> Regards
>
>

-- 
Dr Stephen Brooks

http://www-solar.mcs.st-and.ac.uk/
Solar MHD Theory Group
Tel    ::  01334 463735
Fax    ::  01334 463748
E-mail :: steveb at mcs.st-andrews.ac.uk
---------------------------------------
Mathematical Institute
North Haugh
University of St. Andrews
St Andrews, Fife KY16 9SS
SCOTLAND
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