Thanks Bryn. >>Aside from mentioning CDP and replicating data to another appliance you >>haven't really stated what you're trying to do. [Suresh] - > Bascilly I would like tap/track the all writes happening that mapped lun on the host ( take it as any block device on the host ) , in the format of Offset, Length and Data . and then send this data to CDP appliace . This CDP appliance has the target lun which is intially synced to source lun on the host . after receving the writes happening on host , this cdp applicance apply writes to target lun . so both source lun and target luns are in sync all the time . Can you advise me anything better now ?. Thanks again -----Original Message----- From: Bryn M. Reeves [mailto:bmr@xxxxxxxxxx] Sent: Friday, January 09, 2015 10:29 PM To: device-mapper development Cc: vgoyal@xxxxxxxxxx Subject: Re: Device mapper target driver for Write tracking or Write split On Fri, Jan 09, 2015 at 07:51:08AM -0800, Suresh Babu Kandukuru wrote: > Bryn, Thanks for quick reply. Below items helps to do mirroring and replication . I am looking for something which can track writes( device mapper based block level filter driver) as explained in the below diagram in Linux open source community . Anything that's doing mirroring or replication (or many other useful target functions) is going to need to 'track' writes (normally by copying them and keeping track of the copies in the target). The device-mapper core provides infrastructure to help with this but if none of the existing dm targets provide the functionality you need then you will either need to create one from scratch or extend whatever current target best matches your needs. Aside from mentioning CDP and replicating data to another appliance you haven't really stated what you're trying to do. Regards, Bryn. -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel