I had an odd question recently from a customer – they wanted to know whether NetWorker could tell them what inode a file had when it was backed up. Thankfully, having previous experience with NetWorker and AdvFS, I knew that NetWorker did keep track of inode details during the backup.

The way to find this out is to use the nsrinfo command. Let’s say we’ve got a directory/mount-point, ‘/var’, and we want to see what inode it had during backup. In this case, the command that you would run would be:

# nsrinfo -N /var/ clientName

(Note the use of “/var/”, not “/var”.)

So if I want to find this information out for the client ‘nox’, I’d run:

[root@nox ~]# nsrinfo -vV -N /var/ nox
scanning client `nox’ for all savetimes from the backup namespace
UNIX ASDF v2 file `/var/’, size=660, off=3456572, app=backup(1), date=1251459999 Fri 28 Aug 2009 09:46:39 PM EST, fid = 2304.2147905, file size=4096
ndirentry->2639214 ftp/
[root@nox ~]# nsrinfo -vV -N /var/ nox
scanning client `nox' for all savetimes from the backup namespace
UNIX ASDF v2 file `/var/', size=660, off=3456572, app=backup(1), 
date=1251459999 Fri 28 Aug 2009 09:46:39 PM EST, fid = 2304.2147905, 
file size=4096
  ndirentry->2639214	ftp/

(The rest of the output has been snipped.)

So where, you might wonder, is the inode detail stored in all of this? Look for the ‘fid = X.Y’ part of the output; the inode number is Y – in this case, 2147905. We can verify that by running stat against the directory:

[root@nox ~]# stat /var
  File: `/var'
  Size: 4096      	Blocks: 16         IO Block: 4096   directory
Device: 900h/2304d	Inode: 2147905     Links: 25
Access: (0755/drwxr-xr-x)  Uid: (    0/    root)   Gid: (    0/    root)

As you can see, the inodes match.

So there you have it – you can use NetWorker to confirm/check what inode number a file or directory had when it was backed up.

 

So this morning I was looking through the stats for this blog, and I generated the list of most popular posts thus far. I can’t say any of the results surprised me. Every single one of the top 5 comes from the “Basics” series.

Number 5, on that list, was Basics – Listing Files in a backup. There’s a lot of people out there who want to know how to use nsrinfo in general, and specifically want to know about pulling file lists for savesets. Net result? I think it would be greatly beneficial if in NMC users could double-click on browsable savesets and get a complete listing of files therein.

Number 4 was Basics – mminfo, savetime and greater than/less than. Now, I’m not going to pretend that every person who visited that article was looking for details about how greater than and less than works in mminfo in relation to savetimes, though I suspect a reasonable percentage of people new to mminfo found that interesting. My take on it is that it proves there’s not really enough documentation about mminfo, and that mminfo needs some expansion. My personal preference? Having a full SQL-like query engine for mminfo would greatly expand the options available to NetWorker administrators.

Number 3 on the list is Basics – Changing saveset browse/retention times. As regularly as possible I try to check the search strings that have brought people to my blog (as recorded by wordpress), and I can practically guarantee that every day there are multiple combinations to do with savesets, browse and retention times. Sometimes those combinations reference nsrmm, sometimes they don’t. Clearly, extending saveset browse/retention times in NetWorker needs to be more manageable from within the GUI as a bare minimum. I’ll get to the command line in a moment.

Moving on to number 2, we have something that I get search results for every day without fail. That’s Basics – Fixing “NSR Peer information” errors. It’s actually a reasonably simple error to fix, but sometimes finding the information about it is a bit like the old needle-in-a-haystack. I’m hoping that the posting on it has helped quite a few sites to clear out the warnings/errors in their logs and reduce the amount of clutter being reported.

Finally, for number 1, a topic I’m completely unsurprised to see at the top, we have Basics – Parallelism in NetWorker. Not because it’s difficult, but because there’s no absolute rules, parallelism is a topic in NetWorker that many administrators, regardless of length of time with the product, find challenging at times. Set too low, and backups may overrun. Set too high, and device contention, client slow-downs, recovery performance issues, etc., may come into play. Tuning parallelism in NetWorker has to take a lot into account.

The content of this list suggests a few things to me:

  • None of this information is out of reach in the product manuals, but, since the product manuals are (necessarily) lengthy, it is logistically is out of reach for a lot of users who don’t have time to read lengthy manuals.
  • EMC product management could take a few tips from the top 5 articles on my blog – I think they represent areas that could be improved within usability of the product. While parallelism is not something that can “solved” by changes within the GUI (it is, by necessity, complex), other options, such as improving mminfo search, making saveset contents more accessible within the GUI, etc., are readily fixable.
  • It seems there might be scope for a “Getting Started with NetWorker” style manual. I think a traditional book would (a) be too expensive and (b) be unsuitable. This is the sort of information that people want readily to hand on their desktops.

On the last point, I’m interested in writing such a manual. I obviously have some experience with writing – but more so than just the book, over the years I’ve written literally thousands of pages of NetWorker instructions as part of professional services documentation, training courses, etc.

So here’s a question – would people be interested in say, an eBook along the lines of “Getting Started with NetWorker” that gives basic operational and instruction usage so that rather than having to wade through the (close to 1000+) pages of the official documentation they had something shorter, and geared towards day to day operation?

Let me know what you think.

 

Everyone has had that horror recovery scenario, where a user wants a file recovered, but they can’t tell you where the file was, or even on what machine it was stored. You can find this information out through a series of mminfo and nsrinfo commands, or, if you’re in a hurry and you have IDATA Tools installed, you can run the find-files utility to quickly locate it.

Say for instance I’ve got a user who lost the file “Safari4.0BetaLeo.dmg” somewhere between 6 and 1 week ago on either the machine archon or aralathan. To find where this file may be located in backups, one would run the following command:

[root@nox nsr]# find-files -c archon,aralathan -S "6 weeks ago" -F "last week" 
-f Safari4.0BetaLeo.dmg
=== Probe backups ===
    aralathan
    archon

=== Search for Safari4.0BetaLeo.dmg ===
    Check aralathan, 20 savesets to check
    Check archon, 8 savesets to check

=== Results ===
aralathan:/ @ 04/24/2009 23:45 (384942702)
Volumes: Staging-01, Staging-01.RO
    /Users/preston/Desktop/* Incoming/Safari4.0BetaLeo.dmg

archon:/ @ 04/25/2009 04:27 (15860863)
Volumes: Staging-01, Staging-01.RO
    /Users/preston/Desktop/DNB/Safari4.0BetaLeo.dmg

As I mentioned before, you can run mminfo and nsrinfo queries yourself to do this, but having a tool there just waiting for you to point it in the right direction can be a time-saving boon.

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