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iroorda's avatar
iroorda
14 years ago

Poor speed to tape from Data Domain with Backup Exec

 

Hi,
 
I am using Backup Exec 2010 R3, reading from a CIFS share on a Data Domain DD640 and writing to LTO-4 tapes in a Dell TL2000 tape library. The speeds that I get are unsatisfactory - 26MB/sec at best - and I'm assuming that at that speed my tapes are shoe-shining. I get decent speed (>50MB/sec) when reading from an iSCSI array and writing to tape with the same loader, so I'm fairly sure that the drive isn't the problem. According to the stats on the Data Domain, I am not maxing out the LAN, CPU, or IOPS of the disks. I have talked with Data Domain support; they have told me that the slow speed is likely a result of the overhead associated with CIFS and that 25-30MB/sec is pretty good single-stream read performance for this appliance. They recommend that I try NFS to see if I get better read performance using that protocol.
 
I have two questions. First, does anyone have any other suggestions to improve the speed that I can read from the Data Domain and write to tape using CIFS? I am not assuming that Data Domain support is incorrect, but I thought I would pose the question just in case. Second, what options would I have to back up an NFS export from the Data Domain using Backup Exec?
 
Thanks,
 
Isaac
2010
Backing Up
Backup and Recovery
Backup Exec
Performance

3 Replies

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  • teiva-boy's avatar
    teiva-boy
    Level 6
    14 years ago

    Search my.datadomain.com for "tuning,"

    There are quite a bit of guides there for tuning on Windows.  As well as optimum BackupExec settings.

  • teiva-boy's avatar
    teiva-boy
    Level 6
    14 years ago

    Looking at some performance guides for the DD640 (I can't share them as they are for resellers only)

    The DD640 over a single GbE connecction over CIFS, can do 80MB/s reads.  Over 10GbE, can do 120MB/s over CIFS.  It's much faster if you use other protocols like NFS, BOOST or VTL.  VTL being the fastest.

    How are you connected?  You should be using LACP for the two onboard GbE connections.  You should be on the latest DDOS5.1.  

    I would suggest you also search my.datadomain.com to read up on LMDD and IPerf.  Both are tools to test actual througput from Media server to DD box.  This is the ONLY way to measure throughput accurately for the DD unit.  I'm not sure how you are getting your numbers currently.