-------------------------------------------------- From: "Nadeem M. Khan" <[email protected]> Sent: Monday, November 22, 2010 10:13 AM To: "GNU/Linux Users Group, Mumbai, India" <[email protected]> Subject: Re: [ILUG-BOM] Incremental Backup using rsync
> On Mon, Nov 22, 2010 at 7:43 AM, Binand Sethumadhavan <[email protected]> > wrote: >> 2010/11/22 Kshitiz <[email protected]>: >>> I feel a full backup once in 400 days, with hourly incremental, daily >>> incremental and weekly incremental backup being rotated in a way in >>> which 1 full backup followed by 24 hourly incremental backups, >>> interspersed with 7 daily incremental backups and 5 weekly incremental >>> backups may be protection enough for my data. What is the you all's >>> expert opinion? >> >> I am assuming you meant 40 days, and not 400 days. :-) >> >> Let us say a full backup takes 30 minutes to restore, each weekly >> incremental takes 5 minutes to apply and each daily incremental, 1 >> minute. Let us further say you have an outage 33 days after your >> previous full backup. Now, the time for you to restore is: >> >> 30 minutes to restore the last full backup >> 4 x 5 = 20 minutes to apply the 4 weekly incrementals since the last full >> backup >> 5 x 1 = 5 minutes to apply the 5 daily incrementals since the last >> weekly incremental >> >> Total time taken to restore = 55 minutes ~= 1 hour. > > Nice analysis. > > I feel we can provide better insight if he lets us know what exactly > he is trying to backup. Since he is using rsync, I assume he is > backing up files at the OS level. Now, what application does he use, > and how often to files get generated/modified at the OS level? That > would decide the frequency of his full and incremental backups. > > If we are taking about OLTP here, then logic says the data be stored > in a database, not at the OS level. In such a case, the db will take > care of mttr, etc. The 55 minutes of data loss would be taken care of > by the redo logs (if Oracle). > > I have never come across a situation where I had to run hourly > incremental backups at the OS level. > > Regards, > NMK. > -- > http://mm.glug-bom.org/mailman/listinfo/linuxers > Thank you Nadeem & Binand for your reply. Will revert to you asap. Regards Kshitiz -- http://mm.glug-bom.org/mailman/listinfo/linuxers
