Re: question about ceph and FC SAN LUN data IO path

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 05/13/2013 02:24 PM, Dennis Chen wrote:
Hi,

If I have an OSD attached by a FC SAN device with the connection like this:
OSD HBA-->FC Switch-->SAN storage device.

Then Map a LUN in the SAN to the OSD as its only disk device to save
data. if I have a client also has an HBA and the topology diagram looks
like:

                   osd                                         client
         -------        -------                            ------- -------
        | HBA |      | NIC |  <---------------> | NIC |   | HBA |
         ---+---      --------                            ------- -------
\                                                            /
                   \ /
                        \                                   /
                               \    --------------
                                   | FC Switch |
                                    --------------
                                           |
                                        SAN

Suppose the created LUN above for OSD can be accessed by both osd and
client though FC I/F, the question is:
if I create a rbd block device in osd and map it to client, make a file
system and mount it in client side, then create a file in the mounted
FS. The read/write operation followed for this file will transfer data
though ethernet path or FC path?


That will follow the Ethernet path.

I'm also trying to figure out why you would Ceph here and use RBD? If the client has direct access to the FC, why not have the client access that direcly?

Ceph makes sense when you are running it on multiple fully separated machines, but not if you run it all one one FC SAN imho.

Wido

BRs,
Dennis

--
To unsubscribe from this list: send the line "unsubscribe ceph-devel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


--
Wido den Hollander
42on B.V.

Phone: +31 (0)20 700 9902
Skype: contact42on
--
To unsubscribe from this list: send the line "unsubscribe ceph-devel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [CEPH Users]     [Ceph Large]     [Information on CEPH]     [Linux BTRFS]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]
  Powered by Linux