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NDMP very slow - would this help?

Created: 20 Apr 2013 | 3 comments

Ques : If remote NDMP (NetApp) is slow then direct NDMP would be equally slow? Assuming that there are no netwrok or media server perfromance issues. 
 

Currently running remote NDMP to disk staging  becuse of the unnatural slowness of NetApp NDMP.  Its that slow it takes days to backup and runs at a spped that would shoeshine a tape drive to death ( ~20MB/s).  Found that using smtape type of NDMP backup as waste of time becasue was eithr about the same time or longer.  Given these are single large volumes (~10 TB  with about 75 millions files) it doesn't matter if they are multiplexed or.

My guess would be they would also run at ~20MB/s if the tape drives were directly connected (directNDMP) 

Other vFiler backups on the same controllers seem to run OK casue they are much smaller, this tells me its not a network issue but usuall problem of NetApp being slow.    

Backup environment : NBU 7.5.0.4 W2k8 x64 servers.

Operating Systems:

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mph999's picture

If the slowest point is on the filer (eg, disk read speed) then yesm, it will be slow.

If the slowest point was caused (just for example) the network between the filer/ media server, then providing the disk read speed is good, direct NDMP would be quicker.

In a nutshell, the backups will run as fast as the slowest point.

Martin

 

Regards,  Martin
 
Setting Logs in NetBackup:
http://www.symantec.com/docs/TECH75805
 
jim dalton's picture

My 2c worth: direct NDMP can be amazingly fast.

For reasons best known to a.n.other sm2tape is slow...I suspect this is because its a low prio process so despite it having the resources and with nothing better to do, it still wont commit more cycles to the process. I would love to know how to make it go quicker, I would use it, integrated with Netbackup.

 

NDMP slow phase is due to the vol being crawled through for inodes: you can demo this by having  small numbers of large (say 20Gb) files: it'll be quick: 150M//sec for me.Large numbers of small files of the same size: it'll be slow.

 

Indirect NDMP I have only seen slow BUT you can MPX which may prove beneficial.

 

75 million files suggests its going to be slow.

Jim

Jim-90's picture

Nothing slow on the the IP side.  Other vFilers are running the best as they can (NetApp NDMP is not the fastest kid on the block) 20MB/s is pathetically slow.   Next step will be a NetApp DUMP to NUL that will measure a the ability of NetApp to pull the data off the disks.   I think if was any where near 20 MB/s and maxed out the disks there something terribly wrong with the setup.