Hi Ben,
I'll be the first to say that this doesn't answer your question, but why are you using NDMP for quick disaster recovery? I would think that SnapMirror or SnapVault would be much more accomodating to DR requirements... My guess would be that a block level copy with VSM would be much more efficient...
I would ask your Sales rep or SE for an eval snapmirror license.
--paul
On Wed, 5 Jan 2005 16:26:32 -0800, Ben Rockwood BRockwood@homestead-inc.com wrote:
Happy New Year Toasters.
Does anyone have experience with tuning NDMP? I'm not sure how much tuning is possible, but I'm trying to work out some serious slowness in NDMP Level 0's.
Plenty of people have had these issues before but I'm not finding solutions on NOW or in forums. Here is a time breakdown of a L0 I did: 5 hr 32 min total 35 minutes in Pass I & II 14 minutes in Pass III 3 hr 38 min Pass IV (Stage 1, Creation) 1 hr 21 min Pass IV (Stage 2, Copy) Unknown in Pass V
These numbers are rough based on timestamps during the NDMPcopy itself. The total transfer is about 58G from one 760 to another. It's the first stage of PassIV that really bothers me. During this first part of the pass there is very low CPU utilization and little IO. I need to speed up the process. Since the destination is a recovery filer and not serving data I don't care if it's CPU gets slammed or IO is pushed through the roof, I just need it done quicker.
Is it throttling or can I some how speed it up? I'm using gig as the interconnect but as I understand it Pass IV Stage 1 is all about inode creation whereas Stage2 is the actual data transfer. The data transfer rate is roughly averaging 11MB/s between the two filers which is less than I'd like to see as well, the filer should be capable of handling a tranfer rate of 30MB/s pretty easily.
Any hints or tips from the experienced? This is effectively a test setup before implementing a recovery system on our production 940's in which we'll be moving nearly 7TB of data. Given my findings so far it's going to be pretty nasty.
benr.