LSFS and growth on disk

[Tim]

I have read about how LSFS works and think I understood most of it.

I know that nothing ever gets deleted, the writes go to the head of the 'log'.
This will cause space used on disk to grow, eventually even past the set virtual disk size.

So what I would like to know is how to perform maintenance so the the LSFS files on disk only contain active data?
This will effectively reduce the LSFS files on disk to smallest size that contains all the required data.

Thanks

[Anatoly (staff)]

If you want to keep only active data you need to use *.img files instead of LSFS.

[Tim]

Ok let me reword that question.

How do I stop LSFS files on disk from growing out of control?
If nothing is ever deleted then a 100GB virtual disk could, with enough activity, turn into 1TB on disk?
Please correct me if I'm wrong.

Tim

[Anatoly (staff)]

Right now the unused blocks reprovisioning is initiating by drop of the workload on hte SAN. In one of the nearest builds we will add ability to manually trigger that process.

[robnicholson]

Right now the unused blocks reprovisioning is initiating by drop of the workload on hte SAN

How does one monitor that auto-defragmentation is actually ever running? I guess that load on our SANs will drop overnight but that's just a guess. Maybe a PowerShell script to query the LSFS to show the level of fragmentation? Something simple like:

Get-StarWindLSFSStatistics -Target <name> FL

UsedBlocks: 5,434,341
OverwrittenBlocks: 1,300,321
BlockSize: 512
DefragmentationRunning: no

I notice that StarWind is splitting the LSFS volume into 5GB blocks.

Cheers, Rob.

[Anatoly (staff)]

How does one monitor that auto-defragmentation is actually ever running?

Good question!
We need to add this thing into GUI. Right now you can just check the total size of the virtual disk files.
Also, we will add the possibility to run Defrag manually.

[robnicholson]

Additional question - when you use the "Create clustered storage wizard", are the LSFS devices created with auto-defragmentation turned on or off?

One doesn't know because a) it doesn't ask you during the wizard - just asks if you want it deduplicated or not and b) there doesn't appear to be any way to know whether auto-defragmentation is on or off in the GUI.

I've no problem with a wizard assuming some common options (after all that's what wizards often do compared to the manual approach) but one does need to know either way. I would suggest "auto defragmentation" should be on.

Cheers, Rob.

[Anatoly (staff)]

It`s actually turned on by default.
I think we`ll just take away ability to choose from users since AutoDefrag is the thing that need to be turned on always.

[robnicholson]

I think we`ll just take away ability to choose from users since AutoDefrag is the thing that need to be turned on always.

I agree - you'd have to be slightly mad to not have it turned on

Cheers, Rob.

[anton (staff)]

That's a Company issue. We should not be exporting leverages allowing such a critical influence on the system. We'll fix that in the upcoming builds. Thanks!

[Francesco]

So much for thin provisioning.

[Anatoly (staff)]

For deduplication and snapshots to be more precise.

[Francesco]

When do you think you'll have a fix for this uncontrolled growth?

[Anatoly (staff)]

I hope we`ll see it next week.

[Francesco]

Great, the sooner the better!

After the upgrade, will StarWind automatically shrink the disk files or will we have to recreate them and move the data?