# testing new hdd before use

## nordic bro

I got a new disc large enough to backup everything from the two I'm currently using in my system since I need my computer for work and could theoretically be up and running quickly if one of those two suddenly fail.

so I'm wondering, do you guys do any kind of in-depth or stress testing like seatools long test on a new drive?  I've always just done the short test initially and check the smart log.  then partition and use for a week or two and check again.

but after reading that data can go into a sector which isn't any good meaning the data is already lost, and since the purpose of this disc is a backup, maybe I should run the long seatools test?  even though it's read-only would 'e2fsk -cfvy' on all partitions be a reasonable substitute?  

thanks.

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## NeddySeagoon

nordic bro,

 *Quote:*   

> but after reading that data can go into a sector which isn't any good meaning the data is already lost, ... 

 

Not quite.  The drive detects this condition and remaps the sector to spares built into the drive for this very purpose.

In fact, all drives have surface defects when they are made - they are hidden from the operating system as good spare sectors are mapped in place of the useless ones.  This process continues through the drives useful life. When all the spare sectors are used, the drive is as good as dead.

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## Corona688

You'd be surprised how eerily high a percentage of disk may be reserved for spare sectors these days, too.

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## solamour

Perhaps it's specific to my case rather than a norm; I noticed that when a new disk fails, it usually fails within a month or so. Once they are up and running for a while, they tend to last quite a while before finally going belly up.

Whatever the case is, I consider disks as perishable and nothing can substitute a good backup.

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solLast edited by solamour on Tue Aug 30, 2011 6:27 am; edited 1 time in total

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## Jaglover

I second that, I usually power up the new drive for a couple of days and run smartctl on it. If drive was damaged in transport it will show.

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## redagadir

the phenomenon is well known in industrial manufacturing, the failure probability over time is like a side view of a bathtub, high at the beginning and in the end, low in between.

that said, using only one disk for backup is not the best way to protect data. if your data is important, build a RAID1 system with 2 disks at least, and ready a 3rd.

for stress testing a new hdd, i use these: bonnie++ and iozone3 with different options.

the real test remains running smartctl with destructive write on all disk (obviously you can't use the disk for anything else).

also, know that (cheap?) USB<->SATA adapters usually fail with sustained throughput, so connect the hdd using a docking bay, or even fix mount it.

use rsync if you want to transfer any file, with the -c option.

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