Restore in single user mode - performance issues

Hi,

I had to recover some complete filesystems on a Linux host. The host (NetWorker 7.6.3) was backed up in a traditional way with NetWorker server (7.6.3) via storage node (7.6.3) to a Data Domain system DD860. System had to run in single-user-mode, because Oracle database, application server and some special services had to be off while recovery.

1. First try was to recover from DD via Storage Node, because the host had no direct network connection to DD. We used /nsr/debug/nodirectfile to disable direct recover via DDboost. Performance was horrable: around 150 KB/s. No chance to recover partitions with gbytes of data.

2. Second try was to recover from DD directly. So we managed a network connection to DD (opened some firewalls) and removed /nsr/debug/nodirectfile. Result was fine: around 25 MB/s.

When system was restored I rebooted to runlevel 3 and made a restore of a bigger file that I had the performance issues with in my first try in single user mode. Performance now was fine, no performance issue with restore via storage node. It seemed like some services are needed to be run for a fast recovery. Does anybody know something about it? Is there any missing service that impacts recovery performance?

BTW: Host system was a VMware virtual machine with Linux SLES 11 SP1 for VMware (x86_64). I attach a network performance chart of that machine (u4098004) and it's communication to netwrk01 (NSR server; reading index informations) and stor-sn3 (NSR storage node, restoring data).