SSD’s remaining Lifespan

Solid State Disks, or SSD, are pretty the norm in computers nowadays. They offer the access speed and vibration/ shock stability unmatched by mechanical hard drives. However, how often do you take note of your SSD’s remaining lifespan or wear leveling count? For me, I peeked at it once in a blue moon and it was too late when the SSD failed.

I added a SSD (a Crucial M4 256GB if you are interested) to my iMac (27-inch, Mid 2011) back in year 2012. The iMac has been blazing along well and I did lots of hardware reviews, infrastructure testing (on VM), etc. with it.

Tucked somewhere in the S.M.A.R.T tool, I did noticed that there is a remaining health counter for the SSD. However, I had expected the SSD to gradually fail (like a mechanical drive) with bad sectors appearing and exhibit weird sounds (if any). But nope, it just failed. Some of my applications failed to run properly or they simply just crashes. Without thinking much, I rebooted the iMac and it hung at the boot screen, refusing to show me the desktop.


Investigating and Recovering the iMac

As per standard procedure, launched disk utility and checked the SSD. The test abruptly failed and was recommended to backup whatever is left or accessible and followed by a clean format.

Luckily for me, I have got Time Machine on my Synology DS1515+. I browsed the archive and the last successful backup was last night. Phew. Not too bad.

Dug out a OCZ Vector 256GB SSD that I bought previously and replaced the Crucial M4 256GB SSD. You can read about my previous SSD installation for iMac. Physical replacement done!

Replacing the SSD, reinstalling OS and restoring data!

Found my Sierra installation USB key and kick started the operating system installation. The OS installation took around 10 mins. OS installed!

Followed up with a restore from Time Machine during ‘out of box experience’ (OOBE) set up. An hour or so later, data was restored!

Lastly, since macOS does not enable Trim by default for third party SSD. I enabled Trim support for SSD on macOS Sierra using ‘sudo trimforce enable’.

The whole recovery process took an entire afternoon with most of the time spent on disassembling and assembling the iMac.



This incident dawned on me the importance of back up and monitoring the health of critical components (i.e. SSD, HDD). The health parameters are there for a reason, listen to it. From now on, I shall automate monthly health check on my iMac. I also hope there are features like Seagate IronWolf Health Management for the rest of the brands.

Lastly, I seem to have bad luck with hard disks these couple of months – My DS1515+’s hard drives failed while doing volume expansion. Hope this is the last of it!