Can't view previous SMART test logs &is it in sequence?

[diskdiddler]

DId you have a point you were making?

http://en.wikipedia.org/wiki/S.M.A.R.T.#Self-tests

Yeah, I've never heard of it, that was my point, ever, not once have I heard that term - clearly it exists, yet no smart tool I've ever seen even offers conveyance test in the options to perform it. I've booted from manufacturer provided floppies and iso's for years, never seen it! How does one even initiate such a test?

I'll take into consideration that you had no idea what a conveyance test was when I decide how much to value that opinion.

The issue of infant mortality is well-understood among storage professionals. You can try to bring yourself up to speed by checking out the Google reliability study, http://research.google.com/archive/disk_failures.pdf and other resources available via Google search.

An interpretation of the Google study's observation is that there's basically a window from 3 months to 3 years where drives are least likely to fail.

However, long experience by many people in the business is that drives are most likely to fail in the first month. 1000 hours is a conservative compromise; few failures are noticed between 1000 (my number) and 2160 hours (3 months).

So here's the thing you need to ponder: if you are building a pool with redundancy, and you've got a significantly greater chance of drive failure because of infant mortality issues, do you want to push those drives into production after a mere 24 hours of testing, and risk a double failure? Or is the smart move to wait at LEAST 1000 hours, maybe even 2160 hours, to get your drives properly validated? Because especially for a new pool, they've ALL got that greater risk of failure.

I might have agreed had you called 1000 hours insufficient.

I'm well aware that most electronics die early, this thread is about replacing a disk in an existing, working pool with 2 disk redundancy. This is not about creating a new pool from scratch, where excessive testing might be advisable.

If the replacement disk dies right now, I've still got 5 proven disks in the server.
Furthermore, I'm probably not going to use these disks for more than 2 years and you're suggesting up to 90 days (12% of their expected lifespan) in testing?
I'm going to say you subscribe to the cyberjock school of excessive paranoia, sorry.

The entire point of a RAID setup is that you're prepared for failures. Should I have done a full test? Yeah definitely but 1000 hours of testing in a multi-disk environment is just madness, pure madness.

 

[danb35]

Yeah, I've never heard of it, that was my point, ever, not once have I heard that term - clearly it exists, yet no smart tool I've ever seen even offers conveyance test in the options to perform it. I've booted from manufacturer provided floppies and iso's for years, never seen it! How does one even initiate such a test?

# smartctl -t conveyance /dev/adaX

 

[jgreco]

Yeah, I've never heard of it, that was my point, ever, not once have I heard that term - clearly it exists, yet no smart tool I've ever seen even offers conveyance test in the options to perform it. I've booted from manufacturer provided floppies and iso's for years, never seen it! How does one even initiate such a test?

... send the command to the drive and it does it. The fact that you've never noticed a thing doesn't mean it isn't there.

I'm well aware that most electronics die early, this thread is about replacing a disk in an existing, working pool with 2 disk redundancy. This is not about creating a new pool from scratch, where excessive testing might be advisable.

If the replacement disk dies right now, I've still got 5 proven disks in the server.
Furthermore, I'm probably not going to use these disks for more than 2 years and you're suggesting up to 90 days (12% of their expected lifespan) in testing?
I'm going to say you subscribe to the cyberjock school of excessive paranoia, sorry.

The entire point of a RAID setup is that you're prepared for failures. Should I have done a full test? Yeah definitely but 1000 hours of testing in a multi-disk environment is just madness, pure madness.

No, it isn't. It's simply being prudent to protect against preventable failures. Some of us do this professionally. You are of course free to risk your own data in whatever manner you see fit.

Cyberjock's not too paranoid, by the way. Some of us have a warm standby drive sitting in a RAIDZ3 pool ready for a failure, plus another cold spare that's passed burn-in and qualification ... for 1000 hours.

 

[cyberjock]

Conveyance tests are designed for someone to ensure a disk wasn't damaged during shipping. One of the first tests you should do on a hard drive after shipping/moving significantly is a conveyance test. It's the manufacturer's "one stop shop" to ensure there wasn't mechanical damage during transport.