Enrico, > >>> Hello >>> I'm offering a solution based on our disks where replication and >>> storage management should be made using only ZFS... >>> The test change few bytes on one file ( 10bytes ) and check how many >>> bytes the source sends to target. >>> The customer tried the replication between 2 volume...They compared >>> ZFS replica with true copy replica and they realized the following >>> considerations: >>> >>> 1. ZFS uses a block bigger than HDS true copy >>> 2. true copy sends 32Kbytes and ZFS 100K and more changing only 10 >>> file bytes >>> >>> Can we configure ZFS to improve replication efficiencies ? >>> >>> The solution should consider 5 remote site replicating on one >>> central >>> data-center. Considering the zfs block overhead the customer is >>> thinking to buy a solution based on traditional storage arrays like >>> HDS entry level arrays ( our 2530/2540 ). If so ..with the ZFS the >>> network traffic, storage space become big problems for the customer >>> infrastructures. >>> >>> Are there any documentation explaining internal ZFS replication >>> mechanism to face the customer doubts ? Thanks > Do we need of AVS in our solution to solve the problem ?
AVS, not unlike HDS, does block-based replication based on actual write I/Os to configured devices. Therefore if the means for ZFS to change 10 bytes, results in ZFS writing 100KB or more, AVS will be essentially be no different than HDS in this specific area. Of course this begs to question, is the measure of a 10 byte change to a given file, a viable metric for choosing one form of replication over another? I think, or would hope not. What is need is a characterization of the application(s) write-rate to one or more ZFS filesystems, over the customers requirements for data replication. A good place to start is: http://www.sun.com/storagetek/white-papers/data_replication_strategies.pdf http://www.sun.com/storagetek/white-papers/enterprise_continuity.pdf > >>> Thanks > > _______________________________________________ > zfs-discuss mailing list > zfs-discuss@opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss Jim Dunham Storage Platform Software Group Sun Microsystems, Inc. wk: 781.442.4042 http://blogs.sun.com/avs http://www.opensolaris.org/os/project/avs/ http://www.opensolaris.org/os/project/iscsitgt/ http://www.opensolaris.org/os/community/storage/ _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
