RE: Can Disk mirroring/db snapshots replace the usage oftaking database backups?

Hi JP, a little more thought for the fire...and trying to be a little more helpful than just critical.... >> Based on the frequency level to capture the snapshot, is there any impact on users and environments? let's assume on the surface everything is hunky-dory and all our concerns about improper log backups and things are solved... some may have implied this already, forgive me if i missed those contributions.... what will happen at the network layer? how at the network layer will this falconstor work? is your network robust enough to handle this snapshot, possibly intense dataflow for X many minutes? on the surface your DB may not appear to be impacted by taking the snapshot... but if there is a tremendous amount of effort at network layer.... your users on that same network may all of a "sudden" have problems accessing your DB because the network is flooded? these falconstor folks might have greater bandwith expectations at the network layer than you are prepared to deal with. the database backup technologies... onbar, rman, db2 backup... they are coupled with the DB and can be tweaked accordingly to lessen impact on users. if falconstor negatively flooded the network, what capablities do they offer to "throttle" the snapshot.... and of course if you have to do that, that could extend the duration of the "db block" (if in fact falconstor implements db block under the covers)..... >>Do you see any impact with this Agent on the database environment and users and how does the database instance start to use this disk? let's see... so you have to purchase the falconstor product and then you have to purchase a falconstor informix agent. how does this agent work?... if i have multiple disks for my DB....and falconstor issues the db block.... how then does falconstor take the snapshot....refering to others comments about falconstor speed.... if it dispatches one daemon (pardon my ignorance on falconstor or software of this type's terminology)... if it dispatches one daemon per chunk... how many daemons would it do in your environment and then again how much of a load will it put on your network whilst doing this snapshot?... (see concern above).... i bring the network concerns up because we async some data to our remote site... depending on what our disk admin is syncing/pushing to the remote site... we see negative impacts on our DB performance... only one very good programmer complained once so far (our hardware speed and lots of memory hides a lot of possible issues)...... but when the disk admin is pushign the data to remote site my DB backups will take 6+ hours to run when normally they are around 3 hours..... we worked out an agreement with our disk admin and thing are better now. be educated on how this software will work on and impact your network .... for that will impact your database and then of course your user community. good luck, Norma Jean ________________________________ From: informix-list-bounces@iiug.org [mailto:informix-list-bounces@iiug.org] On Behalf Of jpierrot@chubb.com Sent: Friday, April 11, 2008 1:42 PM To: Kevin Cherkauer Cc: informix-list-bounces@iiug.org; informix-list@iiug.org Subject: Re: Can Disk mirroring/db snapshots replace the usage oftaking database backups? There are a few things I need to add to this post: According to the vendor, FalconStor has a built in snapshot agent for Informix which forces Informix to flush all information to disk and inserts a tag into the data stream being written to disk (presumably at the end of the data being flushed and in front of any new data), per se, the snapshot is consistent as of that point in time. Any update after that doesn't impact the snapshot data. I do not know yet how the snapshot agent triggers Informix to flush everything to disk, but assuming it somehow forces it with an onmode -c. (block). Not sure on how they do it. Based on the frequency level to capture the snapshot, is there any impact on users and environments? Do you see any impact with this Agent on the database environment and users and how does the database instance start to use this disk? Additionally, the Snapshot Agent uses an Informix API that isn't in 7 but was introduced in 9. Any feedback and comments on all the above would be greatly appreciated Regards, jp ============================================================ The information contained in this message may be privileged and confidential and protected from disclosure. If the reader of this message is not the intended recipient, or an employee or agent responsible for delivering this message to the intended recipient, you are hereby notified that any reproduction, dissemination or distribution of this communication is strictly prohibited. If you have received this communication in error, please notify us immediately by replying to the message and deleting it from your computer. Thank you. Tellabs ============================================================