Macbook Pro gained 100GB free space after Total Recovery with Time-Machine

I don't know what is going on with the OS X Lions, but there seems to be some sort of problem with "Other' taking up way too much space on boot drives.

With boot hard drives (not SSD's) the computers performance suffers greatly the more data is on the second 50% of the drive.

Pondini has it laid out better here what is doing what.

http://pondini.org/OSX/DiskSpace.html

I have a more overall performance UT here.

Why is my computer slow?

I think Apple was preparing for all their machines to have SSD's thus bloated OS X with new features that take up more drive space (Verisions and Local TimeMachine backups) but then the price of SSDs didn't come down and they still have to use the old hard drives with the bloated OS X features.

The new iMac's even have a hybrid "Fusion" drive of flash memory and a hard drive.

Apple treats a hard drive as simply storage, you have 500GB and they then use it, but actually you really only can use the first 250GB if you want your machine to remain fast.

I have my boot drive split, so OS X and everything stays on the first 50% of the drive. The other 50% is a bootable clone.

Most commonly used backup methods

If you want your computer to remain fast, head to Disk Utility and make another partition below your OS X one.

This will keep the Lions from getting out of control with all it's saving stuff on the boot volume.

Time Machine doesn't back up the contents of the Trash, logs, or certain temporary files. Although they don't usually take up that much space, it's not out of the question if something was going haywire. Any files that you excluded from backup, intentionally or otherwise, weren't restored.

First of all, your drive is way too filled up. On a physical HD you should try to maintain 40 - 50% clear. On a SSD you can fill up a little more but it too will run well with 40 - 50% clear. If I fill up an external drive as much as you have, it will often fail to mount at all, so its no wonder your computer won't boot. While you have that 100 GB free, you should think about getting an external HD of some kind and backing off as much data as you can. I don't know exactly what is happening with you time machine etc. but you will start having all sorts of anomolies if you overfill your drive.

Barry fisher, greetings:

Barry Fisher wrote:

On a physical HD you should try to maintain 40 - 50% clear. On a SSD you can fill up a little more but it too will run well with 40 - 50% clear.

This does not reflect my experience. I have had HDDs, both internal and external which have been filled to 90%+ capacity encountering no operational difficulties. Some applications require a certain amount of fixed space in order for them to be run but never a percentile of free space. It has been my observation that real problems can start to occur only when the OS initiates a HDD capacity warning. One may experience a very slight performance degradation with a largely 'full' HDD, but there are no other ill effects.

Ciao.

Do you notice any missing files?

OGELTHORPE wrote:

This does not reflect my experience. I have had HDDs, both internal and external which have been filled to 90%+ capacity encountering no operational difficulties.

The machine will work with a 90% filled boot hard drive, the slowdown occurs depending upon what data is on the second 50% of the hard drive.

If it's OS X and programs, they are going to "feel" slower as the heads have to reposition themselves more often as there are smaller sectors on those inner tracks.

As you can see by this image.

Hard drives first write data to the outter tracks and works their way in onto the shorter tracks that hold less data.

Since OS X is installed first on a blank boot hard drive, it's going to write to the fastest outer tracks first, then usually programs and users files kind of get intermixed as the data gets written further inwards.

So a new install of OS X on a 90% full boot hard drive might not feel that much of a performance difference unil later on.

When one upgrades/updates a OS X version to another, if the boot drive is over 50% filled it's going to write the new OS X version to the slowest part of the drive.

If one enables Filevault, it's going to encypt the contents of the drive and place it on the tracks further in, also slowing the read/write speeds of the data placed on those tracks.

So the object is to keep ones OS X and programs off the inner 50% and on the outer 50%, the inner 50% can be users files because it's something that expands and contracts, changes often and isn't used as much as the operating system or programs.

Ideally now with 10.7+ doing all sorts of background saving, TimeMachine local backups and versions, it's likely best with a hard drive on a new machine or after a wipe and fresh install of OS X, is to create a second partition in Disk Utiltiy just for files.

Many Windows PC owners do this, it's a shame we OS X users also now have to do likewise because they intetionally cripple one's performance to force a premature hardware upgrade.

I think you should keep all hard drives completely empty and memorize all your data. That way, seek time is zero and bandwidth is infinite.

Linc Davis wrote:

I think you should keep all hard drives completely empty and memorize all your data. That way, seek time is zero and bandwidth is infinite.

Exactly, keyboards and screens are such a bottleneck. 😁

ds store, greetings; Thank you for this information. It is most illuminating.

My primary reason for my comment to Barry Fisher was that his parameters are not practical and realistic and imply that severe problems may ocurr if more than 50% of a HDD is utilized. Others reading this post may be thus misinformed.

Back to your response, I am in general aware of this information, but what I have never been able to get are any measurement of the impact of filling up of a HDD and the positioning of data. In my communication with Seagate, they indicated only the more a HDD is filled, the slower the performance, but not by how much.

Until I can find actual measurements, this information falls into the category of 'nice to know' but with limited practical value. If you have such information, please let me know.

Ciao.

jlingo527 wrote:

. . .

Today I noticed that I gained about 100GB of free space, became 120GB. How could this be possible?

The discussion has gotten a bit distracted.

As Linc says, Time Machine automatically skips a number of things that don't need to be backed-up, but usually nowhere near that much. So you likely had one of the problems in Where did my Disk Space go?, but there's no way to tell now.

Keep an eye on it; if free space starts shrinking again, for no good reason, take a look at that link. The problem may still exist, and that should help you find it.