Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
----- Original Message ----- > From: "Ted Young" <mail at tedyoung.me> > To: drbd-user at lists.linbit.com > Sent: Tuesday, January 24, 2012 5:50:09 PM > Subject: Re: [DRBD-user] Persistent Device Names > > > Additionally when you mirror disks directly with drbd, your > > drbd-resources > are fixed to the size of the disk-pairs. When you mirror lvm volumes, > they > can have the size they need to have to fulfill their > task. You can > have > drbd-resources of only some MB but also resources of the size of two > or > three of your disks toghether. > > Thank you Arnold for your reply. I think you may have hit the > impedance > mismatch on the head! You are recommending putting DRBD on top of a > large > LVM volume. In fact, I was planning on putting LVM on top of a bunch > of > mirrored (DRBD) physical drives. When one puts DRBD on top of LVM > one risks > losing the entire logical volume if a single drive fails. In such a > case, > DRBD would have to re-sync the entire logical volume. By putting LVM > on top > of DRBD, DRBD would only have to re-sync the failed hard drive. > > That being said, I just discovered today that DRBD volumes are a > relatively > new feature. Prior to version 8.4 one would have to create a > separate DRBD > resource for every synchronized block device. Obviously, this would > be > really annoying and so using DRBD on top of LVM makes sense. > However, I was > planning on defining each physical hard drive as a DRBD volume within > one > resource then using LVM to stripe/aggregate them. So perhaps the > reason I > have found little on the subject is that most people have > traditionally put > DRBD on top of LVM instead of the other way around. > > Ted Young I happen to do DRBD over LVM which I like however there is documentation on doing both... LVM -> DRBD -> LVM (however little I may understand of why you would want this) See the DRBD users guide here for 8.3.x: http://www.drbd.org/users-guide-legacy/s-nested-lvm.html or here for 8.4.x: http://www.drbd.org/users-guide/s-nested-lvm.html HTH Jake > > > > _______________________________________________ > drbd-user mailing list > drbd-user at lists.linbit.com > http://lists.linbit.com/mailman/listinfo/drbd-user > >