[CentOS] What FileSystems for large stores and very very large stores?

Wed Aug 7 09:45:34 UTC 2013
Steve Brooks <steveb at mcs.st-and.ac.uk>

On Tue, 6 Aug 2013, SilverTip257 wrote:

> On Tue, Aug 6, 2013 at 8:58 PM, Eliezer Croitoru <eliezer at ngtech.co.il>wrote:
>> OK so back to the issue in hands.
>> The issue is that I have a mail storage for more then 65k users per
>> domain and the ext4 doesn't support this size of directory list.
>> The reiser FS indeed fits for the purpose but ext4 doesn't even start to
>> scratch it.
>> Now the real question is that:
>> What FS will you use for dovecot backhand to store a domain with more
>> then 65k users?
> XFS?
> Used for situations where one has "lots or large" as Dave Chinner says [0]
> Meaning lots of files or large files.
> [0] http://www.youtube.com/watch?v=i3IreQHLELU
>> Eliezer
>> On 07/05/2013 04:45 PM, Eliezer Croitoru wrote:
>>> I was learning about the different FS exists.
>>> I was working on systems that ReiserFS was the star but since there is
>>> no longer support from the creator there are other consolidations to be
>>> done.
>>> I want to ask about couple FS options.
>>> EXT4 which is amazing for one node but for more it's another story.
>>> I have heard about GFS2 and GlusterFS and read the docs and official
>>> materials from RH on them.
>>> In the RH docs it states the EXT4 limit files per directory is 65k and I
>>> had a directory which was pretty loaded with files and I am unsure
>>> exactly what was the size but I am almost sure it was larger the 65k
>>> files per directory.
>>> I was considering using GlusterFS for a very large storage system with
>>> NFS front.
>>> I am still unsure EXT4 should or shouldn't be able to handle more then
>>> 16TB since the linux kernel ext4 docs at:
>>> https://www.kernel.org/doc/Documentation/filesystems/ext4.txt in
>> section 2.1
>>> it states: * ability to use filesystems > 16TB (e2fsprogs support not
>>> available yet).
>>> so can I use it or not?? if there are no tools to handle this size then
>>> I cannot trust it.
>>> I want to create a storage with more then 16TB based on GlusterFS since
>>> it allows me to use 2-3 rings FS which will allow me to put the storage
>>> in a form of:
>>> 1 client -> HA NFS servers -> GlusterFS cluster.
>>> it seems to more that GlusterFS is a better choice then Swift since RH
>>> do provide support for it.
>>> Every response will be appreciated.
>>> Thanks,
>>> Eliezer

Just for interest I have had two 44TB "raid 6" arrays using EXT4, running 
with heavy useage 24/7 on el6 now since January 2013 without any problems 
so far. I rebuilt "e2fsprogs" from source. Something along the lines below 
looking at my notes.

wget http://atoomnet.net/files/rpm/e2fsprogs/e2fsprogs-1.42.6-1.el6.src.rpm
yum-builddep e2fsprogs-1.42.6-1.el6.src.rpm
rpmbuild --rebuild --recompile e2fsprogs-1.42.6-1.el6.src.rpm
cd /root/rpmbuild/RPMS/x86_64
rpm -Uvh *.rpm

###### build array with a partition #######
parted /dev/sda mkpart primary ext4 1 -1
mkfs.ext4 -L sraid1v  -E stride=64,stripe-width=384  /dev/sda1

###### build array without a partition #######

mkfs.ext4 -L sraid1v  -E stride=64,stripe-width=384  /dev/sda

Maybe this will help someone.

Cheers Steve

Dr Stephen Brooks

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