[datphp]

The MTBF is typically much higher than regular HDDs, and their reliability is probably at the level described for Hitachi (can't give actual stats though, my experience is limited to hundreds not thousands)

Those drives aren't designed for HDD farms though. They are meant to be used in environments where a failure is a big problem and paying a lot more for a bit more reliability is worth it. Like that 1U server you got in a datacenter with 2 disks in RAID1.

If you have thousands of disks replacing is part of the daily routine, and isn't an issue at all (as numbers suggest in article/comments)

[lsc]

That isn't why you buy enterprise drives. Or, at least, I've spent several Porsches worth of money that I could reasonably have spent on Porsches on enterprise drives, and that isn't why I bought enterprise drives.

I buy all enterprise drives. Not because I can't handle replacing a disk; I live within walking distance of the coresite santa clara location where most of my servers are, and actually kinda enjoy that sort of thing. (Yes, yes, I'm sick. But what of it?)

I pay double for 'enterprise grade' drives because more often than the consumer-grade drives, they fail clean.

That's the thing... what does it mean to have a drive "fail?" The vast majority of my failures with consumer grade drives just /degrade/ rather than outright failing. They get shittier and shittier over time. And yes, with sufficient software you can detect this and automatically fail them, but I don't have that. the "enterprise sata" stuff? More often than not, the things actually fail before they degrade to the point where I notice them causing problems with other things.

I buy enterprise grade, not because they last longer, (In fact, I see no evidence that they do) but because they tend to work or fail, whereas consumer grade drives exist on a continuum between "working" and "failing"

(Of course, even the enterprise stuff isn't 100%... but it's much better.)

[hga]

Well, nowadays I buy them because that's the only way you get a 5 year warranty; I only build systems with 5 year design lifetimes (even for the parents; saves a lot of hassle).

Although I have seen some evidence of consumer grade drives "failing dirty". E.g. in 2002 I tried a couple of 5 year warranty Seagate Barracudas in a new machine; it didn't take long for one of them to outright fail a 4K portion of the disk. I actually wrote a little C program to recover everything but that one bit (and it was a file I could then recover the missing data from), and switched back to SCSI enterprise drives for my main system drives and haven't looked back (granted, those are as fast as I can buy, and that means SCSI enterprise). And that includes a couple of machines I built for a non-profit that are exactly what datphp describes.

And, yeah, these best of the best drives do fail, at least I had at least one of the Seagate Cheeta 10K drives I bought back in 2002 completely fail, I think both eventually, the 2nd after 5 years had passed.

[lsc]

>I actually wrote a little C program to recover everything but that one bit (and it was a file I could then recover the missing data from),

'ddrescue' is a program I use in similar situations. (not to discourage you from writing your own; doing that sort of thing leads to a deeper understanding of what is going on.)

[hga]

I was still stuck in Windows (Windows 2000), and it was quite a bit faster to write the program than find a solution on the net like that on a live CD, download it, etc. Having started on C in 1979 (sic) I knew it cold by then.

But, yeah, confirming exactly what was the problem was good, especially since it was extremely odd. All blocks readable except for those 8, although the drive knew it was in trouble.

It reminds me of problems others have reported, especially those using high level error checking file systems like ZFS, where the drive accidentally writes to the wrong location correct data correctly, so the internal CRC passes on reads. The firmware in drives is said to be getting to full OS complexity....