Re: [Veritas-bu] Speaking of NTFS:

On Fri, Feb 15, 2008 at 7:35 AM, Mellor, Adam A. <Adam.Mellor AT woodside.com DOT au> wrote:

I do however back up Windows file servers, Are there any guidelines to
NTFS volumes that people would recommend ?

I thinking along the lines:

Defragmenting,
Number of streams,
LUN Virtulization tech,
Volume Sizes,
Maintaining free space,
Snapshot methods,
impact of ohh sooo many small files

Performance improvements with Advanced client / Flashbackup,
SAN Media server,
(For the adventurous) SAN client ?

For example, i currently have pain with about a dozen windows clients,
from what i can tell

we do not do defragmentaion

That's not a backup issue - the Windows admins should be doing that on a regular basis anyway. You can't worry about it. The worse the fragmentation, the worse the load on the client.

their LUNS live on HP EVA's sharing spindles with hosts

Same here. Not an issue for us. In fact, some of our DSSUs were on the same EVA as the hosts they're backing up. We've since moved most of our DSSUs off to a SATABeast.

Free Space is minimum (~7%)

Not an issue for backups unless you're using FlashBackups - there is a space requirement for the snapshots.

Volumes are only ~500GB

That's that not that bad unless you have lots of little files.

We backup with Multiple streams (Exceeds weekend (and daily) backup window if we don't (Windows are large)

So do we with a few exceptions - large FlashBackups on 32-bit Windows systems has a tendency to tip the box over so those single-stream. Because they're clusters and using virtual servers, NetBackup gives us no good way of single-streaming them so we use a dedicated DSSU with a concurrent job limit of 1 to act as the throttle point.

Currently backing up the windows dataservers is a pain point for me, I
am interested in hearing peoples learnings / Golden rules when it comes
to backing up large (over 500GB) NTFS Volumes.

If you have a large number of files, use FlashBackup. For us, it cuts the time in half. 64-bit Windows is also appears much faster at feeding the backup stream than 32-bit Windows. TOE cards seem to help but only on file servers - on SQL servers, there are rumored bugs in the driver that cause all sorts of grief (lots and lots of little transactions which is not typical for file/backup servers).

Here's an example of a recent largeish Windows backup picked at random: 525GB backed up (as reported by NetBackup), 21M files, using FlashBackup on a 64-bit Windows box. Elapsed time 5 hours and 17 minutes with a reported speed of about 29MB/sec. That was writing to DSSU on a Solaris media server (different EVA than the source volume).

We don't present any Windows volumes (other than DSSUs) greater than 1TB for two reasons: 1) the backup time gets too long, and 2) if you get into a chkdsk situation (don't forget, NTFS is non-journaling), you may need to take the volume offline for a long time...

We don't use SAN Media Servers but hope to test the SAN Client sometime...it's on the TODO list.

.../Ed

--
Ed Wilts, Mounds View, MN, USA
mailto:ewilts AT ewilts DOT org

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