Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
Thank you, Great information, Unfortunately the ancient kernel I am running, and will be running for a while, Does not compile 8.3.x code, Some of the required kernel features do not exist in 2.4, Mounting of a secondary, in a non production environment, and expecting data mismatches, gave me better results that I expected, At one point I might abandon this idea, But so far it does whatever I need.... Thanks a lot, Mike Fiedler Ehud Karni wrote: > > On Tue, 3 Nov 2009 11:57:10 paziulek wrote: >> >> I would like to create 2 copies of the primary in a "chain" >> configuration: >> ( sys1 mirror to sys2, sys2 mirror to sys3 - [same data on all] ) >> >> sys1/sda10 -> sys2/sda10 -> sys3sda10 > > Below is my configuration that does exactly that. > >> Q1: is there a way of mirroring the secondary? >> Q2: is there a way of mirroring primary to 2 secondaries? ( I am using >> drbd >> 0.7.5 on a 2.4.21 system ) > > Q1 - yes, see my configuration. > > Q2 - AFAIK yes, with stacked primary (what I do on the secondary). > > Also, I think it works on DRBD 8.3.x only (not on 7.x.x). > >> and if somebody would ask why I would need such config: >> I want to mount the sdaX filesystem on sys3 in read-only mode to have >> access >> to semi-real-time data and at the same time have full mirror on sys2 with >> no >> sdaX access other than DRBD. > > As far as my understanding of DRBD goes, you can not do that. > You can NOT mount (even read only) an updating secondary. > > Ehud. > > > -------------------- /etc/drbd.conf -------------------- > ## lcl-nfs --> bu-lcl --> bu-rmt > > common { > protocol A; > > startup { > wfc-timeout 60; > } > > disk { > on-io-error pass_on ; > no-disk-barrier ; > no-disk-flushes ; > # no-md-flushes; > no-disk-drain ; > } > > net { > # this is the size of the tcp socket send buffer increase it > _carefully_ !! > sndbuf-size 0; > rcvbuf-size 0; > > # timeout 60; # 6 seconds (unit = 0.1 seconds) > # connect-int 10; # 10 seconds (unit = 1 second) > # ping-int 10; # 10 seconds (unit = 1 second) > # ping-timeout 5; # 500 ms (unit = 0.1 seconds) > > max-buffers 8192; > unplug-watermark 8192; > > # The highest number of data blocks between two write barriers. > max-epoch-size 8192; > > data-integrity-alg "md5"; > > } > > # rate is given in units of _byte_ not bit > syncer { > verify-alg md5 ; > > # Configures the size of the active set. Each extent is 4M, > # 257 Extents ~> 1GB active set size. > # BTW, the hash algorithm works best if the number of al-extents is > prime. > al-extents 499; > > } > > } > > resource rmt { > disk { > ## stack size 1459913168 K > ## meta size 262144 K (256 MB) > size 1460175312K; > no-md-flushes ; > } > > startup { > become-primary-on bu-lcl ; > } > > # rate is given in units of _byte_ not bit > # slow line to Med1 - Max of 6MB > syncer { > rate 4M ; > } > > on bu-lcl { > device /dev/drbd0; > disk /dev/sdb1; > address 192.168.0.84:7789; > meta-disk /dev/sda4[1]; > } > > on bu-rmt { > device /dev/drbd0; > disk /dev/md_d0p1; > address 192.168.1.87:7788; > meta-disk /dev/cciss/c0d0p3[0]; > } > > } > > > resource lcl { > disk { > size 1459913168K; > } > > startup { > become-primary-on lcl-nfs ; > } > > # rate is given in units of _byte_ not bit > syncer { > rate 30M ; > } > > on lcl-nfs { > device /dev/drbd0; > disk /dev/sdb; > address 192.168.239.1:7789; > meta-disk internal; > } > > stacked-on-top-of rmt { > device /dev/drbd1; > address 192.168.239.2:7788; > } > > } > > > > > -- > Ehud Karni Tel: +972-3-7966-561 /"\ > Mivtach - Simon Fax: +972-3-7976-561 \ / ASCII Ribbon Campaign > Insurance agencies (USA) voice mail and X Against HTML Mail > http://www.mvs.co.il FAX: 1-815-5509341 / \ > GnuPG: 98EA398D <http://www.keyserver.net/> Better Safe Than Sorry > _______________________________________________ > drbd-user mailing list > drbd-user at lists.linbit.com > http://lists.linbit.com/mailman/listinfo/drbd-user > > -- View this message in context: http://old.nabble.com/3-node-chain-config-tp26163369p26196295.html Sent from the DRBD - User mailing list archive at Nabble.com.