backup was fast but MySQL part of restore is SLOW

2 posts / 0 new
Topic locked
Last post
#1 Thu, 09/09/2010 - 03:15
jmunjr

backup was fast but MySQL part of restore is SLOW

I did a backup of a server that was about 1.5GB in size. The backup via Virtualmin only took roughly 15 minutes. I am restoring this backup to a new system that has double the # of cores and 3 times the memory. The thing is, the restore is painfully slow - going on 3+ hours now..

Using phpmyadmin to look at processes I can see that individual MySQL processes are being executed but I don't understand why this is taking so long.

Any ideas why a backup that took 15 minutes is taking hours to restore ? It is a new server that afaik is configured properly.

Thu, 09/09/2010 - 09:30
andreychek

Howdy,

How large is the database in question?

While 3 hours does seem to be particularly long, it's not unexpected that an import takes a lot longer than the dump that occurs during the backup process.

To do a dump of your database, MySQL is simply doing a bunch of reads, and putting it all into a file.

To do an import, a lot of writes take place, and writes are dramatically slower than reads.

My guess is that you just have a large database or a complex dataset... and that hopefully, it doesn't come up frequently that you need to restore this particular Virtual Server :-)

-Eric

Topic locked