SSD & Defrag

[Chuckster]

I've recently purchased quite a few of the Samsung SSD 850 Evo to give some of our old machines a new lease of life.

 

Anyhow, for a few weeks, I have had it installed in my machine and quite often - well, all of the time, I leave my machine continually running from Monday through to Friday every week. The problem is I have realised that there is a Microsoft default scheduled defrag task that's been running once a week at 1am for almost a month. In other words, the SSD I have inside of my machine has been defragmented 4 times.

 

I haven't noticed any degrading performance of the SSD yet, but what's the likely hood of it dying on me? Have I considerably shortened its lifespan? Should I replace it?

 

This is my first foray into SSD territory.

[Arthur]

It's nothing to worry about. See the first link for a complete explanation.

 

The real and complete story - Does Windows defragment your SSD?

 

No, Windows is not foolishly or blindly running a defrag on your SSD every night, and no, Windows defrag isn't shortening the life of your SSD unnecessarily. Modern SSDs don't work the same way that we are used to with traditional hard drives.

 

Yes, your SSD's file system sometimes needs a kind of defragmentation and that's handled by Windows, monthly by default, when appropriate. The intent is to maximize performance and a long life. If you disable defragmentation completely, you are taking a risk that your filesystem metadata could reach maximum fragmentation and get you potentially in trouble.

 

Why weekly defrags are turned on for SSDs under Windows 8

 

... even though defrag is listed for Solid State Drives, it is not an actual defragmentation that is taking place, which in turn means, there is no reason to worry about the defrag listings in the application log.

Edited April 16, 2015 by Arthur

[Crumpet]

No idea myself apart from that SSD's aren't meant to be defragged.

[rickjames]

No idea myself apart from that SSD's aren't meant to be defragged.

 

+1, or at least that's what I thought!

[Geoff]

No need to defrag a SSD as the seek time to data is the same regardless (no spinning rust involved). SSDs (if they support it, and you should try and get one that does) do tidy themselves up with something called TRIM.

 

Trim (computing) - Wikipedia, the free encyclopedia

[Arthur]

No need to defrag an SSD as the seek time to data is the same regardless

See the first link above.

 

Storage Optimizer will defrag an SSD once a month if volume snapshots are enabled. This is by design and necessary due to slow volsnap copy on write performance on fragmented SSD volumes. It’s also somewhat of a misconception that fragmentation is not a problem on SSDs. If an SSD gets too fragmented you can hit maximum file fragmentation (when the metadata can’t represent any more file fragments) which will result in errors when you try to write/extend a file. Furthermore, more file fragments means more metadata to process while reading/writing a file, which can lead to slower performance.

 

As far as Retrim is concerned, this command should run on the schedule specified in the dfrgui UI. Retrim is necessary because of the way TRIM is processed in the file systems. Due to the varying performance of hardware responding to TRIM, TRIM is processed asynchronously by the file system. When a file is deleted or space is otherwise freed, the file system queues the trim request to be processed. To limit the peek resource usage this queue may only grow to a maximum number of trim requests. If the queue is of max size, incoming TRIM requests may be dropped. This is okay because we will periodically come through and do a Retrim with Storage Optimizer. The Retrim is done at a granularity that should avoid hitting the maximum TRIM request queue size where TRIMs are dropped.

[ZeroHour]

If you move (aka dont reinstall) Windows you should ensure you run the performance score thing in Control Panel after, that ensure Windows 7 is running in SSD settings but that may be a legacy issue.

[Geoff]

See the first link above.

 

Enabling and keeping volume snapshots (Shadow Copy) on an SSD is lunacy. You should move your VSS Snapshot Location off the SSD.

[Arthur]

Enabling and keeping volume snapshots (Shadow Copy) on an SSD is lunacy.

Why do you say that? VSS isn't going to wear out the SSD.

 

I have had volume snapshots stored on the same SSD I also use for Windows and applications for the last six months and the total amount of data written is 3.09 TB. That's hardly anything in the scheme of things!

 

At the current rate it would take me almost 21 years to exceed the endurance figures stated by the manufacturer.

 

http://vgy.me/bEALdy.png

 

http://vgy.me/lqormp.png

 

As The Tech Report (and other websites) have proven; it takes a lot of effort to kill the NAND in an SSD.

 

• techreport.com/review/27909/the-ssd-endurance-experiment-theyre-all-dead
  
• kitguru.net/components/ssd-drives/zardon/ocz-competition-winner-final-arc-100-hits-695-5tb/
  

@Chuckster's 850 EVO SSD has a 5 year or 75 TBW warranty. With normal use the warranty would have expired long before he reaches 75 terabytes.

[ITGuyWestMidlands]

Im guessing its thought that Its just an expensive way to store data thats not being accessed or needs to be accessed athigh speed

[Geoff]

It's called tiering. 'Archive Data' has no business being on your most expensive per Gb storage.

 

Hierarchical storage management - Wikipedia, the free encyclopedia

[gsk]

It's called tiering. 'Archive Data' has no business being on your most expensive per Gb storage.

 

Hierarchical storage management - Wikipedia, the free encyclopedia

 

If there's space then why not? As space gets tighter then by all means move it to cheaper slower storage to free up the fast stuff for regularly used data. Lunacy is a bit harsh though.

[Chuckster]

Thanks for all the info guys.

 

In the end I decided to delete the scheduled default defrag task using a startup script just to be on the safe side.

 

I think Windows 8 and upwards handle defrag better than 7.

[Arthur]

I think Windows 8 and upwards handle defrag better than 7.

FWIW, Windows 7 will automatically disable defrag for SSDs. By deleting the scheduled task you have also prevented any internal or external HDDs from being automatically defragged on those PCs.

 

Will disk defragmentation be disabled by default on SSDs?

Yes. The automatic scheduling of defragmentation will exclude partitions on devices that declare themselves as SSDs. Additionally, if the system disk has random read performance characteristics above the threshold of 8 MB/sec, then it too will be excluded. The threshold was determined by internal analysis.

The random read threshold test was added to the final product to address the fact that few SSDs on the market today properly identify themselves as SSDs. 8 MB/sec is a relatively conservative rate. While none of our tested HDDs could approach 8 MB/sec, all of our tested SSDs exceeded that threshold. SSD performance ranged between 11 MB/sec and 130 MB/sec. Of the 182 HDDs tested, only 6 configurations managed to exceed 2 MB/sec on our random read test. The other 176 ranged between 0.8 MB/sec and 1.6 MB/sec.

 

Source: http://blogs.msdn.com/b/e7/archive/2009/05/05/support-and-q-a-for-solid-state-drives-and.aspx

 

It's called tiering.

Indeed, but I don't see how that is relevant in @Chuckster's case. The SSDs are going in old PCs, not a SAN, NAS or server.

[Arthur]

If you move (aka don't reinstall) Windows you should ensure you run the performance score thing in Control Panel after, that ensure Windows 7 is running in SSD settings but that may be a legacy issue.

Windows 7 onwards will automatically run WinSAT, but if for some reason it doesn't you can run it from the Command Prompt manually (using the command below). This will ensure that SSDs are detected properly if you have cloned Windows from a HDD.

 

winsat formal -restart clean