[DRBD-user] LVM (not cLVM) on pri/pri?

Kelly Byrd kbyrd-drbd at memcpy.com
Wed Sep 19 14:33:09 CEST 2007

Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.

> if it is static, anyways,
> why not have drbd on top of lvs,
> and run "classical" Primary/Secondary per drbd/lv?
I would like this bug I have concerns about scaling 
to 24 drbds, see below.

So let's say I was talking about"
storage -> 1 drbd -> 24 LVs.

I belive you're suggesting.

storage -> 24 LVs -> 24 drbds (on per LV)

I asked about this on the list a few days ago and got no response. I'll
ask the same questions here:

- Are there problems with this many drbds? What's the overhead of all those
drbd worker threads and all those TCP connections vs. just one or two?

- Working out the sync groups would be kind of tough. My underlying storage
is a single big RAIDed mass of disks. Would I be better off to let all sync
serially or randomly pick groups of three to keep the RAID busy?

- Is there any way to specify a global sync rate so that if only one drbd
syncing it'll take the full sync rate, but 6 or 7 drbds syncing will
share that same sync rate? 

> pri/pri does basically work,
> but is more complicated to handle.

I'm learning that during testing.

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