[CentOS] network raid file system/server

Fri Jun 15 02:42:18 UTC 2007
Feizhou <feizhou at graffiti.net>

Farkas Levente wrote:
> Petr "Qaxi" Klíma wrote:
>> Farkas Levente napsal(a):
>>> hi,
>>> we've a few 10-20 server in a lan each has 4-8 hdd. we'd like to create
>>> one big file server on these server hard disks and we'd like to create
>>> it in a redundant way ie:
>>> - if one (or more) of the hdd or server fails the whole filesystem still
>>> usable and consistent.
>>> - any server in this farm can see the same storage/filesystem.
>>> it's someting a big network raid5-6... storage where we have about
>>> 40<partition added to the same network volume. and there is an fs over
>>> it which hide all internal network raid functionality.
>>> is there any such solution? i can't find any way to do this on our
>>> linux servers.
>>>   
>> what about souch FS blocks path
>>
>> server->gfs->LVM-> raid1(disc0)-> iscsi
>> initiator->local-eth0->LANswitch0->remote-eth0->iscsi-target-on_file_server0->LVM->raid(1,5,6,...)->HDD(1,2,3,4,......)
>>
>>                   \->LVM-> raid1(disc1)-> iscsi
>> initiator->local-eth1->LANswitch1->remote-eth0->iscsi-target-on_file_server1->LVM->raid(1,5,6,...)->HDD(1,2,3,4,......)
>>
>>                   \-------------||----------------
>>
>> in souch setup you have no single point of failure
>>
>> bacause of money you can decrease number of switches (FE to 2 and
>> connect each server and FS to both of them)
>>
>>
>> If you do not need concurent access from 1+ servers to one fs
>> (partition, logicalvolume, same file ...) you do not need gfs ..
>>
> 
> sorry this graph is a bit complicated:-(
> how comes the iscsi into this image? iscsi under raid?

In this scenario, iscsi provides the devices remotely and the server 
handles the raiding of the devices.

> can you explain it a bit more detailed?

The boxes with disks are now just 'disk servers' and those disks are 
exported to the servers that will provide the filesystem layer. iscsi is 
the technology used to export the disks in this scenario.