Some quick SSD Advice? My boot drive died!

[HCMarkus]

Does the second drive have to be a SSD with Trim or can I boot from any disk and run Repair Disk?

Any drive as long as it has OSX installed with Trim enabled.

[mikehalloran]

Any drive as long as it has OSX installed with Trim enabled.

Is Trim enabled for mechanical drives? I've not heard of that.

[HCMarkus]

Any drive as long as it has OSX installed with Trim enabled.

Is Trim enabled for mechanical drives? I've not heard of that.

Trim needs to be enabled for SSDs. This can be done despite the fact you are not booting from an SSD.

When you boot into Snow Leopard, Lion, Mountain Lion or Mavericks from your alternate boot drive (SSD or spinner, but must* be a separate physical disk from the Yosemite boot drive), first enable Trim (I'd install and use Trim Enabler from Cindori), then re-boot from the alternate boot drive to allow the change to take effect, then launch Disk Utility and Repair your SSD(s). When you are in Disk Utility, you select the formatted disk, not the top-level disk to "repair". Note that the SSD being repaired must be on a Trim-capable interface (i.e. NOT in a USB 3.0 dock or enclosure). At the end of the SSD repair status message, you will see a message that all free space has been trimmed.

After you have Repaired all your SSDs, re-boot from your Yosemite SSD. Trim need not be enabled in Yosemite, but periodic repeat of the above will be required to maintain your drive in top condition, with the time between Trims determined by write activity and how full the drive is.

*I'm pretty sure you have to boot from a separate physical drive, but it is possible you could boot from a separate partition on the same physical drive. I haven't tried that.

[davedempsey]

I've just ordered a new 15" Retina Macbook Pro, which will obviously come with Yosemite. I also ordered 2 x Crucial 512gb MX100 and a Neutrino dual Thunderbolt/USB3 enclosure. I'll be setting this up with K10 and a few other instrument libraries on the Thunderbolt SSDs as a live keyboard rig. I'll also using it for live recording with my new PA system.
Because the Thunderbolt case is powered I will be able to occasionally leave it powered up overnight for the Crucial active GC to do it's job. As there is plenty of capacity I'm thinking I may not need to worry about TRIM - particularly as neither of the SSDs will be a boot drive. Am I remotely right in this thinking or would I be better off considering a bootable 10.9 with Trim Enabler? If so, will the new Macbook Pro boot in 10.9 and how should I go about setting this up? Thanks

[HCMarkus]

Your internal Apple SSD will have Trim enabled from the git go because it is an Apple drive. As such, you might want to do your recording on that drive; the PCI SSD will be able to handle as many tracks as you need.

If your externals are used exclusively to house VI sample sets, they won't need Trim, because you will only be reading from these drives. You can fill them very close to capacity if using them as read only.

I would suggest that the earliest version of Mac OS your new Mac will probably support is the version that was out when the Mac was first released. Apple's 13 and 15-inch Retina MacBook Pros received a minor update on Tuesday, July 29, 2014.

[mikehalloran]

Well, I tried it after enabling Trim Enabler 3.3 on my iMac's internal 7200rpm HD. My 845DC EVO SSD is connected via eSATA.

When you are in Disk Utility, you select the formatted disk, not the top-level disk to "repair"

I don't think that matters. These two reports are for the top level followed by the disk image. I put the lines in bold.

Per this page, you should see it in Console.
http://apple.stackexchange.com/question ... free-space

Actually, Console did not show much and didn't show Trim nor any other part of Disk Repair. The following reports are from Disk Utility:

(Drive - top level)

Verifying and repairing partition map for “Samsung SSD 845DC EVO 960GB Media”
Checking prerequisites
Checking the partition list
Adjusting partition map to fit whole disk as required
Checking for an EFI system partition
Checking the EFI system partition’s size
Checking the EFI system partition’s file system
Checking all HFS data partition loader spaces
Checking booter partitions
Checking booter partition disk1s3
Checking file system
Checking Journaled HFS Plus volume.
Checking extents overflow file.
Checking catalog file.
Checking multi-linked files.
Checking catalog hierarchy.
Checking extended attributes file.
Checking volume bitmap.
Checking volume information.
Trimming unused blocks.
The volume Recovery HD appears to be OK.
Volume repair complete.
Updating boot support partitions for the volume as required.
Reviewing boot support loaders
Checking Core Storage Physical Volume partitions
Updating Windows boot.ini files as required
The partition map appears to be OK

(Disk image)

Verify and Repair volume “845 EVO”
Checking file system
Checking Journaled HFS Plus volume.
Checking extents overflow file.
Checking catalog file.
Checking multi-linked files.
Checking catalog hierarchy.
Checking extended attributes file.
Checking volume bitmap.
Checking volume information.
Trimming unused blocks.
The volume 845 EVO appears to be OK.
Volume repair complete.
Updating boot support partitions for the volume as required.

[mikehalloran]

I may not need to worry about TRIM - particularly as neither of the SSDs will be a boot drive.

Not an issue. Trim is already enabled. As I showed above, if you run Disk Repair on your Thunderbolt externals, it will run Trim automatically.

If you connect the externals via USB 2 or 3, you cannot Trim them.

[davedempsey]

OK - looks like I'm in the clear either way
Either, as HCMarkus suggests: I don't need to worry about Trim on the external sample SSDs and I record to the Apple supplied internal, which is Trim enabled or, as Mike says, because Trim is enabled on the Macbook Pro I will be able to trim the externals simply by running Disk Utility. Thanks gentlemen - I'll have a look at what's what when it all arrives but I'm thinking recording audio to the internal is the most likely approach so I won't need the Thunderbolt case except when playing
There will actually be recording/PA jobs where I won't need the Macbook Pro either as the console (Allen & Heath Qu series) has an internal multitrack to USB3 HDD capability. 16 mono and 1 stereo direct to a Samsung M3 500GB USB3 Portable External Hard Drive will be fine for some of the smaller line ups.

[Phil O]

..first enable Trim (I'd install and use Trim Enabler from Cindori), then re-boot from the alternate boot drive to allow the change to take effect, then launch Disk Utility and Repair your SSD(s).

But that defeats the whole purpose of NOT enabling Trim on the Yosemite boot drive in the first place (Cindori Trim Enabler turns off kext signing - which we're trying to avoid). Or am I missing something?

Phil

[HCMarkus]

..first enable Trim (I'd install and use Trim Enabler from Cindori), then re-boot from the alternate boot drive to allow the change to take effect, then launch Disk Utility and Repair your SSD(s).

But that defeats the whole purpose of NOT enabling Trim on the Yosemite boot drive in the first place (Cindori Trim Enabler turns off kext signing - which we're trying to avoid). Or am I missing something?

Phil

When operating your Mac under any pre-Yosemite OS, kext signing is off. So when you boot from your alternate drive with Trim enabled, you can Trim your SSDs. This communicates to the SSDs which files have been erased (Trim informs SSDs what the OS already knows) so the SSD knows which cells can be erased in advance, saving wear and tear on your SSDs. When you boot back into Yosemite, Trim is off, but the information was previously passed to the SSD when the drive was Trimmed.

Mike, I think you may have confused things a tad in your last post. If I am reading your log correctly, you are trimming a Samsung 845 SSD, which means (if you are operating in Yosemite) that you have disabled Kext signing and enabled Trim, likely via Trim Enabler. Or that you are operating from a pre-Yosemite OS with Trim Enabled. Yes? As such, all SSDs being run from this boot drive will be trimmed when they are repaired. I don't think this would happen if you hadn't enabled Trim using Trim Enabler.*

*However, it could be that if Trim is on for an Apple-branded boot SSD (as it is by default) all SSDs will be trimmed if repaired. Is this the case with your Mac?

[mikehalloran]

..first enable Trim (I'd install and use Trim Enabler from Cindori), then re-boot from the alternate boot drive to allow the change to take effect, then launch Disk Utility and Repair your SSD(s).

But that defeats the whole purpose of NOT enabling Trim on the Yosemite boot drive in the first place (Cindori Trim Enabler turns off kext signing - which we're trying to avoid). Or am I missing something?

Phil

You're missing something. This is about using a second drive to trim empty blocks on a Yosemite SSD manually.

The other drive that you use can be formatted in any OS you desire from 10.6.8 on. It has to be able to boot the system, of course, and must be connected via SATA, eSATA, TB or PCIe. Running it occasionally to trim a Yosemite SSD does not have any effect on Kext checking on the target drive.

[Phil O]

When operating your Mac under any pre-Yosemite OS, kext signing is off. So when you boot from your alternate drive with Trim enabled, you can Trim your SSDs. This communicates to the SSDs which files have been erased (Trim informs SSDs what the OS already knows) so the SSD knows which cells can be erased in advance, saving wear and tear on your SSDs. When you boot back into Yosemite, Trim is off, but the information was previously passed to the SSD when the drive was Trimmed.

So let me see if I have this straight.
1) Install Trim Enabler on my pre-Yosemite drive (it's a spinner with Mavericks).
2) I boot from Mavericks and turn Trim on with Trim Enabler.
3) Run Disk Utility and repair my SSD.
4) Re-boot from my SSD (running Yosemite).

Correct?

[HCMarkus]

Running it occasionally to trim a Yosemite SSD does not have any effect on Kext checking on the target drive.

This.

[Phil O]

You're missing something.

Yes, I was missing something. I didn't realize you could enable trim while booting from a non-SSD drive. Thanks for clearing that up. Now it makes sense.

Phil

[mikehalloran]

If I am reading your log correctly

You are not.

I was testing to see if the way you and others described it would work from a mechanical HD in another OS (Mavericks in my case). According to Disk Utility, it does, the way that you described.

That I have Trim enabled on the target drive has no bearing on the result except that it probably ran much faster since there are no empty blocks that need trimming. This was a test I ran just to see the results. I will leave trim enabled on my 845 EVO and keep it as my boot drive.

The way that many others described with Console showing the results is not correct.

I think that, since one can run it on the disk image and are not confined to the top level, it should work from a partition. My SSD is too full for me to create a second partiton and test this. As I can boot from a second drive anyway, it's not an issue for me. I've not regretted having OWC install an eSATA port when I bought my iMac new.