Frequent Notebook Hard Drive Head Unloading (and tips) Revisited
Saw a recent comment from a mac mini owner that installed a Travelstar 7K750 HTS727550A9E364 500GB 2.5" HDD and noticed a high rate of load cycles (per smart utility reading). He also (later) found a review at amazon from a user of the same drive about the frequent head unloading behavior. (In some cases you may not hear the drive cycling, although some do.)
He was trying a script/utility ("Keep Drive Spinning", to prevent drives going to sleep) as a workaround but not sure that is worthwhile for this. (Some laptop and 'green' drives may unload the heads after as little as 5 seconds of inactivity.) I can't recall the source now but there was a similar script/util in the past for owners of optical drives with firmware that would go to sleep and not be usable, despite OS X energy saver settings. Sometimes the drive mfr has a utility to turn off energy saving 'features' like this, but if so they're usually for Windows, not OS X. (Below is link to past article from a mac pro owner that used a PC WD Util on his Green drives via a DOS boot CD.)
(Update: He later tried hdapm in OS X 10.8/10.6 and it appears to be working/helping.)
I hadn't thought about this since our long page from early 2009 on Notebook HD Load Cycle Counts from OS X users, where some reported cycle counts exceeding the mfr's rating. (Some had high rates (cycles per hour), others not.) Page has OS X Smart Utility support's comments back then about the SMART readings. (Six were over 1M, with one at 1.5M+.) Reports included load cycles, power on hours, drive firmware version, mac model and if drive sleep was enabled in OS X.
About Using OS X 'HDAPM' to Disable HDD Energy Saving Modes
Never had to use it myself (and would be leery with OS X 10.9 and later) but there were some posts here years ago on using 'hdapm' in OS X 10.6 and earlier. (From mckinlay.net.nz/hdapm/, currently v1.2 from Aug 25, 2012.) The last report I recall on hdapm here was in 2010 from a WD Scorpio 750GB notebook drive user (running OS X 10.6) that said hdapm helped with frequent load cycles. (He noticed the clicking/head unloading right away.) A clip from his comments back then:
(OS X 10.6 user report from 2010)
"I replaced WD5000BEVT (one year old) with WD7500KEVT last week. I had noticed a clicking noise would often occur (since the swap)...
I used "hdapm disk0 254" instead of using "hdapm disk0 max"
(FYI: Site also has a hdapm usage guide with notes and caveats. It runs at startup and may not be compatible with later OS's. I'd ask before installing.)
No more clicking noise and Load Cycle Count is not really increasing so far. (Before this fix, it kept increasing by more than 100 within a couple of hours.)..."
(As mentioned above, a Travelstar 7K750 user later said HDAPM v1.2 helped with the drive clicking/head unloading and reported it working with his OS X 10.8.x/10.6.8 volumes.) Not sure if common, but an old report from an OS X 10.5.6 user on the cycle count page mentioned his drives had problems going into sleep mode afterwards. (Older version/drives/OS.)
Another past article (from 2010) on the subject was about Using WDidle3 to disable WD Green HDD Head Parking from a 2008 Mac Pro owner that used Windows (in VM) and a DOS boot CD. (Info/links there are from 2010 and may have changed.)
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