> Hello Group, > > Sorry if this double posts, I received an error when Sending. > > I was provided with a largish (~27GB) Firebird 2.5 backup file (gbak) > yesterday. I have been restoring this on Windows 2012R2 running 2.5.6 Classic > using gbak with the -service_mgr switch. This particular VM only has a single > CPU core but it is connected to the SAN and isn't doing anything else. I am > remote desktop'd into the machine. > > I have been tracking the restore through several mechanisms: > * -v switch of gbak > * How large the file is on disk > * CPU utilisation (Resource Monitor) > * Disk I/O (Resource Monitor) > > The first 40GB or so of the restored FDB took about an hour or so. The I/O for > fb_inet_server.exe was consistently in the 30MB/s range (usually about 10 read > from the fbk and 20 write to the fdb file) > The next 10 GB took 10 hours. Now obviously when it gets to "activating and > creating deferred index xyz" it slows down, but I cannot see where the > bottleneck is. I have seen extended periods of about 1MB/s reads corresponding > with 5% CPU utilisation whilst activating some of those indices. I copied an > unrelated 20GB file in the same folder and it happily copied at 50MB/s so > there > is definitely capacity that isn't being used. > > I can see that when it activates indices on larger tables it is creating temp > files and these are at least being written to at 8+ MB/s. > > Although I get that activating the indices is going to be slower than > restoring > the data, I was expecting to see it either CPU and/or disk bound at any moment > in time. (Plenty of headroom for memory and network utilisation is very low).
The restore process is bound to a single physical core. I've seen something similar in the past, where basically no resource (CPU, disk I/O - throughput + IOPS) being exhausted, thus not bound to available hardware. Do you have an Antivirus solution running affecting the restored Firebird database and/or temporary created files during restore? You may also vote for: http://tracker.firebirdsql.org/browse/CORE-2992 -- With regards, Thomas Steinmaurer http://www.upscene.com Professional Tools and Services for Firebird FB TraceManager, IB LogManager, Database Health Check, Tuning etc.
