[DRBD-user] mount seconday read-write

[H.D.]

On 29.06.2007 00:10, Lars Ellenberg wrote:
> what is your backend storage?

3ware 3650 BBU
6x 320GB WDE
Raid 10, 16k stripe

> kernel?

2.6.21

> lvm version?

2.02.17

> what does "lvs -o +devices --segments" say?

LV          VG   Attr   #Str Type   SSize   Devices
backup      vg   owi-a-    1 linear 450.00G /dev/sda3(76833)
backup-snap vg   swi-ao    1 linear  15.00G /dev/sda3(199713)
data        vg   -wi-ao    1 linear 300.00G /dev/sda3(0)
meta        vg   -wi-ao    1 linear 132.00M /dev/sda3(76800)

> filesystem?

XFS, nobarrier, not aligned.

> RAM?

4GB

> cpus?

2x Xeon 5130 @ 2.00GHz

> in short, in my experience having the snapshot
> on the same pv as the origin may cause serious pain.

 From what I can tell, this is way less problematic with hardware 
controllers with big write cache. What ever they do, they seem to handle 
the copy on write for LVM snap quite good.


-- 
Regards,
H.D.