Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
On Thursday 06 November 2008 16:42:45 Allen Chen wrote: > Mark, thanks a lot for your help...a couple questions: > > You can do this, but its a little complicated. (And performance may > > stink) > > Why do you say performance may stink? Would you recommend me having one > primary server running development and database, backed up with the > secondary server? You'll get roughly double the I/O on each machine because it's having to do I/O for each database. Depending on how fast your disks and network interconnect are, this may adversly affect performance; especially on the production database. > > The way I'd probably approach it is thus: (Assuming, for example, 100GB > > disks) > > > > Partition 1 = 10GB = / > > Partition 2 = 2GB = Swap > > Partition 3 = 88GB = <drbd> > > What do you mean by <drbd>? Does it matter what mount point I use for > this? No the mount point doesn't matter, but that'll (probably) be controlled by the drbddisk resource agent for heartbeat, so you'll probably never mount it by hand (except maybe initially for testing). Don't forget that because you have two resources than can possibly me mounted on the same machine at the same time, you'll want to mount them on different mount points. Eg: /dev/drbd0 -> /export/production-db /dev/drbd1 -> /export/testing-db > Also, how does drbd know what /dev/drbd0 is? Do I have to set this > somewhere? You are setting it, in drbd.conf - thats exactly what the "device /dev/drbd0" line is defining. DRBD is an extra layer on-top of the disk and under the filesystem. If you wanted to you could have: Raw disks: /dev/sda /dev/sdb Turn them into a software mirror: /dev/md0 Put LVM on top: /dev/mapper/vg0-root /dev/mapper/vg0-swap /dev/mapper/vg0-drbd_raw0 /dev/mapper/vg0-drbd_raw1 Add DRBD: /dev/drbd0 (made from /dev/mapper/vg0-drbd_raw0 on each box) /dev/drbd1 (made from /dev/mapper/vg0-drbd_raw1 on each box) Make filesystems: mke2fs -j /dev/drbd0 mke2fs -j /dev/drbd1 Mount them (via heartbeat when you're in a cluster): mount /dev/drbd0 /export/production-db mount /dev/drbd0 /export/testing-db And so on... Mark. -- Mark Watts BSc RHCE MBCS Senior Systems Engineer QinetiQ Applied Technologies GPG Key: http://www.linux-corner.info/mwatts.gpg -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 197 bytes Desc: This is a digitally signed message part. URL: <http://lists.linbit.com/pipermail/drbd-user/attachments/20081106/fc46b21f/attachment.pgp>