NetApp SnapManager for Exchange failing with VSS_E_WRITERERROR_RETRYABLE

Running into a problem with Exchange 2010, a FAS2240-4 and SnapManager for Exchange 7.1 where backups would randomly fail every now and then started failing consistently.

Our DFM server would send us an e-mail when the failure occurred that looked like this:

The backup failure would also knock the databases offline and require us to re-sync them the next day.

Digging into the SME logs we found the following:

NetApp provides this page for what they call “Common VSS errors”: https://kb.netapp.com/support/index?page=content&id=1010785&locale=en_US

None of the suggestions there helped us.

In the end I found this forum post for a different product: https://community.emc.com/thread/168678?tstart=0 and applied the registry edits they suggested here: https://community.emc.com/message/705346#705346

and then rebooted our Exchange server running SME.

Since making the change roughly 20 days ago we haven’t had a single failed backup.

VeraCrypt CLI Benchmark Script

I was setting up VeraCrypt on a Raspberry Pi 2 the other day so I could use it as a backup target for my main server and was curious how fast, hahaha just kidding, I mean how slow VeraCrypt would be.

To my disappointment VeraCrypt does not provide a method for running the benchmark built into the GUI via the CLI.

This is the nice benchmark you can run from the GUI:

veracryptBenchmark

So I took some time this weekend and wrote a simple BASH script you can use to benchmark the CLI version of VeraCrypt.

I only tested it with VeraCrupt 1.18a. Chances are if you run it with a previous version you’ll get some really fast times for the new Encryption/Hashes they added in 1.18 because the test won’t actually run.

The benchmark I wrote simply outputs how long it takes to create and encrypt a container of a specific size. It’s not quite as good as the GUI version which outputs the actual speed but it’s at least something. I think this will work on any version of Linux. I tried to use only build-in system utilities and since I wrote it on CentOS 6 means I probably used some of the oldest GNU utilities still commonly used.

During my testing I found that having a container size to small would result in all times being nearly the same with the exception of ripemd160 and streebog. To get better results I recommend using at least a 1GB test file size on modern hardware. Even at 1GB you can see the sample from my main server has each encryption and hash type only varying by 2-45 seconds.

Here is a sample of what the script outputs:

I will admit I don’t fully understand these results. I would have expected much more variety in timing between the different types of encryption under a single hash type. Especially on the Raspberry Pi 2.

The script does a simply container creation benchmark in it’s default state. However if you add  <USERNAME RUNNING BENCHMARK> ALL=NOPASSWD: <PATH TO bin/veracrypt>  to your sudo file and change  FILLCONTAINER=0  to  FILLCONTAINER=1  it will perform file write speed benchmark.

and here is the script itself:

I’m not super confident in the output. Some of the numbers leave me scratching my head. It’s completely possible I’ve got something totally wrong with this script. Please feel free to post comments/revisions.