Got a EMC DataDomain?

Are you restores slow?

Recently we had to restore our 5TB prod database to rebuild an AG node. Here’s some things we learned along the way to hopefully help you speed up your restores.

Backup your VLDB to multiple files. We found 12 to be the sweet spot in our setup. Make sure you’re going to 10gig NICs on both ends of the transfer.

In terms of folder directories on that thing we learned to go wide and small. Let me explain. Our setup is this:
\\datadomain\sql\sqlbu\\\Full or Tlog

Under Tlog we break out by day of the week. We’ve found too many files in a folder cause the DD to choke.

We also learned that you can overrun the DD with work. We could kick off all our backups to an Isilon and be fine. The DD can’t handle that, we’d get “network name not found.” The DD is serving up CIFS and it appears to be not too hard to overrun. To avoid this we use CMS to stagger our backups into groups at different times. Tlogs are generally okay running at top/bottom of the hour. Probably because they’re small and quick.

There’s a registry key you can modify to change the timeout (I don’t have the link) for timeout for CIFS in Windows but we weren’t comfortable with that idea.

That’s all I’ve got for now, if we think or find more I’ll update this posting.

EDIT/UPDATE Here’s some EMC KBs that may help:
KB181958_Poor_Restore_Speed
KB182042_DDR_Performance_TroubleshootingGuide_PDF
KB182188_CIFS_and_Networking_Tuning
KB182268_TroubleShooting_CIFS_Performance

Second Edit: Our OS for DataDomain is 5.5.2.2 as of this writing with all the above

One thought on “Got a EMC DataDomain?

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s