I'm doing my first tests with drbd. My configuration is two pcs with two hdd each. One drive is xenserver the second is drbd dedicated. On the drbd dedicated drive, I created /dev/sdb1 which in drbd.conf is assigned to drbd0.
Well, because it is a test environment, I messed up the things a bit and so I had to erase drbd0 (which still is not clear to me which is the correct procedure, but I did it) and, to be sure, I also deleted and recreated /dev/sdb1. The idea was to start over with the creation of drbd0 resource. The first issue I had was about one error that was exiting the command *drbdadm create-md drbd0*. Googleing I've found the solution was to (I'm not so strong with dd) issue this command *dd if=/dev/zero bs=1M count=1 of=/dev/sdb; sync*, looks like that first 1MB data are moved (?), anyway this worked. Then *drbdadm create-md drbd0* worked again and I finished the sequence # drbdadm create-md drbd0 #Create device metadata # drbdadm attach drbd0 #Attach to backing device # drbdadm syncer drbd0 #Set synchronization parameters # drbdadm connect drbd0 #Connect to peer last I launched the primary command and started the sync # drbdadm -- --overwrite-data-of-peer primary drbd0 and the sync worked fine, with a final average speed of 81MB/sec, in 35 minutes the 200GB volume was synced, I also copied and pasted to my notes the cat /proc/drbd command result while syncing [r...@xenserver-2 dev]# cat /proc/drbd version: 8.3.8.1 (api:88/proto:86-94) GIT-hash: 0d8589fcc32c874df57c930ca1691399b55ec893 build by [email protected], 2010-07-17 10:04:02 0: cs:SyncSource ro:Primary/Secondary ds:UpToDate/Inconsistent C r---- ns:935040 nr:0 dw:0 dr:11435392 al:0 bm:697 lo:145 pe:0 ua:145 ap:0 ep:1 wo:b oos:183876844 [>...................] sync'ed: 5.9% (179564/190732)M finish: 0:34:18 speed: 89,308 (76,232) K/sec when finished, it was late night and so I turned off the secondary, last the primary and I went at home. Now I'm here to go on with my tests. Turned on the primary, turned on the secondary and with my big surprise, I've found this [r...@xenserver-2 ~]# drbd-overview 0:drbd0 Unconfigured . . . . so I also lauched cat /proc/drbd [r...@xenserver-2 ~]# cat /proc/drbd version: 8.3.8.1 (api:88/proto:86-94) GIT-hash: 0d8589fcc32c874df57c930ca1691399b55ec893 build by [email protected], 2010-07-17 10:04:02 0: cs:Unconfigured so I issued [r...@xenserver-2 ~]# drbdadm up drbd0 Can not open device '/dev/sdb1': No such file or directory Command 'drbdsetup 0 disk /dev/sdb1 /dev/sdb1 internal --set-defaults --create-device --max-bio-bvecs=1 --on-io-error=detach' terminated with exit code 20 drbdadm attach drbd0: exited with code 20 and because of the message, I checked with fdisk -l [r...@xenserver-2 ~]# fdisk -l Disk /dev/sda: 500.1 GB, 500107862016 bytes 255 heads, 63 sectors/track, 60801 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System /dev/sda1 * 1 523 4194304 83 Linux Partition 1 does not end on cylinder boundary. /dev/sda2 523 1045 4194304 83 Linux /dev/sda3 1045 60801 479995393 8e Linux LVM Disk /dev/sdb: 1000.2 GB, 1000215724032 bytes 255 heads, 63 sectors/track, 121602 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Disk /dev/sdb doesn't contain a valid partition table Yes it is, /dev/sdb1 is disappeared... on both computers... Below you find the drbd.conf. My question are: - which is the correct mode to erase one drbd resource ? - is it possible what described above? - to be able to do such "disaster" (I'm thinking about a production environment), what could be the error/mistake? - with the following configuration file, both the drbd are starting in secondary mode, maybe this is wanted by drbd concept, but I can't understand it very well. I mean, when everything works fine, I have one primary and one secondary. If I do a clean shutdown and I shut down first of all the secondary, next I shut down the primary, why starting up first the primary and last the secondary both of them are secondary? Is it the only solution *become-primary-on server-1* statement? If yes... I have another issue.. this didn't worked... and powercycling the two pcs in the correct order, again returned a secondary/secondary situation. - Is it correct to use the server name in the following statement *become-primary-on server-1* ? - Which are the downsides of usignthis setting in the drbd.conf: *become-primary-on server-1* ? Thank you for any tip and help, follows the conf file Robert drbd.conf # You can find an example in /usr/share/doc/drbd.../drbd.conf.example #include "drbd.d/global_common.conf"; #include "drbd.d/*.res"; global { usage-count yes; } common { syncer { rate 1G; verify-alg md5; csums-alg md5; } } resource drbd0 { protocol C; startup { #become-primary-on xenserver-2; } net { cram-hmac-alg md5; shared-secret "ColdWater"; sndbuf-size 0; rcvbuf-size 0; data-integrity-alg md5; } disk { max-bio-bvecs 1; on-io-error detach; } on server-1 { device /dev/drbd0; disk /dev/sdb1; address 10.1.1.2:7789; meta-disk internal; } on server-2 { device /dev/drbd0; disk /dev/sdb1; address 10.1.1.3:7789; meta-disk internal; } handlers { split-brain "/usr/lib/drbd/notify-split-brain.sh root"; } }
_______________________________________________ drbd-user mailing list [email protected] http://lists.linbit.com/mailman/listinfo/drbd-user
