HOW MANY Donors?

[posidon]

Specific to Rosewood 1TB /2TB & later disks ,How many donor disks are needed if data size is large ?

Company where I outsource head transplant related work often says multiple donors (at a times they have taken 6 donors) if data size is large.
is it that Heads wear out fast due to non precise alignment by them or this happens with everyone .
I know in factory they use " Servo writers "& other advanced equipments to adjust flying height. May be its not possible in manual head transplant.
I am curious whether there is any trick to prolong life of heads or this is indeed true.

[pcimage]

Sounds likes you need to find a new outsource partner.

[einstein9]

Sounds likes you need to find a new outsource partner.

+1

Its all about Experience... when you are used to it you will Waste few donors...

But seagate drives are diff. sometimes 2-3 donors depends on how bad is it but NEVER wasted 6 donors for a case.

FYI - sometimes i use the SAME donor for 2-3 cases.

[rogfanther]

I would venture to say it depends on how bad the disk surface is, and about the experience of the person doing the job.

Sometimes, only experience will tell when to quit, while an unexperienced person would keep throwing heads at it..

[labtech]

Are you paying for those donors every single time a new one is in need for the same recovery?

[posidon]

Thank you all for your valuable suggestions.
I would say rogfanther is right ,it depends on individual case & several parameters like platter degradation /scratches/ size & type of data etc.
Here I am talking about seagate rosewood 1Tb /2 TB /3 TB only. Generally other drives do not require multiple donors.

[lcoughey]

With rosewood, I've only had one case where I went through 3 sets of donor heads. Usually we are lucky if they work at all with 1 set.

[pcimage]

Maybe we’re lucky then...

Our average is 90% success with one set of heads, with 5% using more than one set and 5% total failure. Excluding ones with obvious unrecoverable MD.

[labtech]

Maybe we’re lucky then...

Our average is 90% success with one set of heads, with 5% using more than one set and 5% total failure. Excluding ones with obvious unrecoverable MD.

Same here.

[lcoughey]

I was counting the obviously DOA drives too.

[posidon]

Sean & labtech
Pls. note our recoveries are far different than yours. We deal with non-technical customers like photographers who use disk roughly ,overstress it using beyond its rated capacity. Often data size is in Terabytes or 90% of disk capacity. Disk Platters are degraded with dust. To add more trouble disk has gone through all types of mechanical stress like shocks /vibrations , accidental fall etc.
To recover such disks your claim of single donor does not justify.

[rogfanther]

@posidon,

That would describe most of the common customers. The only thing that could be called "roughly" would be carrying the disk in a bag and subjecting it to shocks in the way. Disks full of data doesn´t change the situation or difficulty of recovery. Shock, vibration , falls ? Check. Customers have the habit to drop their disks, normally after they just backed up their files to it and deleted the original ones.

Biggest situation would be that when something happens, customer should stop using the disk, store it safely and take it to data recovery. That could mean the difference between using just one head in a disk that falled once, and trying to recover a disk that fallen then was hammered for days long with all of the free/pirated software one can find in the ´net ( or even worse, when someone decided to try hdddegenerator or spinwrong in it )

[labtech]

Sean & labtech
We deal with non-technical customers like photographers who use disk roughly, overstress it using beyond its rated capacity.

I know what you mean, so not different at all. The majority of Rosewoods I have been working on come from those Lacie orange externals that photographers and videographers use.

Often data size is in Terabytes or 90% of disk capacity.

Very true, same here. Why? Because photographers and videographers work with big size projects combining photos and large videos. In particular, I have noticed many who use those drives with Adobe Premier software, stressing the drive and causing failure. Had at least 3 with this exact circumstances in a 2 week span.

Disk Platters are degraded with dust.

This should not be the case, unless they open it up, which they should not do. Some minimal dust is present in many drives. In my experience with Rosewoods, in regular mechanical failures, noticed they don't have as many bad sectors as other brand drives.

To add more trouble disk has gone through all types of mechanical stress like shocks /vibrations , accidental fall etc.

That's what the customers do, it is typical.

Pls. note our recoveries are far different than yours. To recover such disks your claim of single donor does not justify.

Again, this was more or less a rate in "normal circumstances". Severe physical shocks/drops, then that is a different story, which would be normal to expect/have low success rate.