Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
bcnx wrote: > > > On Thursday 11 November 2010 13:07:09 I. Schumacher wrote: >> I am administrator of an Alfresco DMS running on an dedicated ubuntu >> server >> and is backedup to a streamer via a simple cron job. >> Unfortunately my predecessor (who set up this backup process) did not >> know >> that streaming a backup while the DMS is running causes mysql database >> inconsistencies preventing the DMS to boot after recovery. boo-hoo >> Running a proper cold back requires approx 2h while the DMS is shutdown. >> Thats just to long. >> >> One way would be to set up a slave-read-only-dms-site with mysql >> replication which can be shutdown for backup anytime while the master >> system is still running. In my opinion this is a waste of ressources >> because the slave site got to be up all the time, only building indices >> out of the replicated mysql data. >> >> In the course of an Upgrade to a newer version of the DMS I plan to >> implement a new backup process using DRBD involving a well equipped >> Master-DMS-Site and a MiniDRBD-Site for backup on another machine. >> >> 1. I have two virtual machines on two separate physical machines. VM1= >> MasterSite VM2=MiniDRBD >> 2. VM1 is running Ubuntu Server, RDBD, iptables, sshd, mysqld, >> oOffice-headless and tomcat. >> 3. Residents of VM2 are Ubuntu Server, RDBD, sshd and iptables >> 4. VM1 and VM2 use a virtual HardDisk /dev/sdb each residing on the >> corresponding physical machine >> 5. RDBD repilicates "VM1/dev/sdb0" to "VM2/dev/sdb0" via /dev/drdb0 >> 6. VM1 stores all DMS relevant data including mysql database and indices >> on >> /dev/drdb0 >> >> To stream a cold BackUp with minimal DownTime I intend to use the >> following >> procedure: >> >> 1. crontab a shell script on VM1 which >> => stops DMS closing the database properly >> => RDBD replicates the closed state of the database to VM2/dev/sdb0 via >> /dev/drbd0 >> => stops replication via "drbdadm disconnect MyFS" >> => starts the DMS again >> => waits for 2.5h and starts replication via "drbdadm connect MyFS" >> => exits >> >> 2. Five Minutes after 1. started I crontab a shell script on VM2 which >> => mounts VM2/dev/drdb0 to e.g. /media/drdb0 >> => streams all files to tape via "tar cvf - /media/drdb0/* | dd >> of=/dev/str0/n block-size=4096" >> => umounts /media/drdb0 >> => exits >> >> (I think that:) >> >> Streaming a BackUp that way reduces the downtime of the Master >> (VM1/alfresco) to about 10 seconds instead of 2 hours. Additionally it (i >> hope) nearly halves required CPU time and RAM usage in comparison to the >> mysql-replication approach that is recommended by the Alfresco-DMS >> vendor. >> >> (:but I may be wrong) >> >> Some general questions: >> >> Q1. I wonder if DRDB will autosync all changes made on the master during >> the "disconnect" to the slave after a "drbdadm connect MyFS" (in script >> 1. >> on VM1). >> >> Q2. How long will it take drbd to replicate the closed state of a 150mb >> database to VM2 so I can stop replication? (1GB/s LAN) >> >> Q3. What do you think would be the minimum specs for my miniRDBD machine >> (VM2). (128RAM,1core,256swap?) >> >> Q4. Do you have any suggestions how to use drbd a smarter way for my >> backup >> purposes. >> >> Q5. <Non drbd question> What is the best way to invoke all commands from >> only one script on VM1? Commands on VM2 will have to be executed as root. >> How can I do that without storing my root password as plaintext inside >> the >> script. I know I did that some time ago but I forgot how... >> >> I hope you can help me. >> Thanks a lot in advance. ;) >> >> Dramatic > > > Would using LVM snapshotting be a possibility? If you use it for your > MYSQL > storage, it can provide you with a stable readonly copy when you take it > after > shutting down MYSQL. If you use it for your VM storage, you could copy > your > entire guest after pauzing or saving it. > > > B. > _______________________________________________ > drbd-user mailing list > drbd-user at lists.linbit.com > http://lists.linbit.com/mailman/listinfo/drbd-user > > How long would a LVM snapshot take when I backup the entire guest with approx. 100gb? Goal number One is to bring the MasterDMS up again as fast as possible after shutting down. I. -- View this message in context: http://old.nabble.com/Request-comments%3A-DRBD-to-cold-BackUp-DMS-with-minimal-DownTime-tp30188891p30198375.html Sent from the DRBD - User mailing list archive at Nabble.com.