Raid 5 with 2 failed hdd? possible to recover?

[LostDataSa]

Hi
I got a client with 6 SAS drives in RAID 5, but 2 drives totally dead (scratches). the dead drives are number 5 and 6 (last 2).

is it possible to recover the data from such case?

[eazycut]

Hi m8!

I am sorry to say that your data is lost.
It doesnt matter how many drives are in use, a RAID 5 array only allows for recovery in the event that just one disk fail.
In your case two disk failure with scratches on SAS drives is certainly game over.

[lcoughey]

Depends on what they need recovered...but pretty much screwed.

[drHDD]

Depends of how big stripe you could get good files up to 4*stripe size.

[einstein9]

Depends of how big stripe you could get good files up to 4*stripe size.

+10
had many with good fair results (better than nothing)

[day1data]

If you can get one of the 2 drives recovered you can rebuild the last one using parity from the rest of the drives.

But 2 drives you are screwed I'm afraid.

[Amarbir[CDR-Labs]]

Hi
I got a client with 6 SAS drives in RAID 5, but 2 drives totally dead (scratches). the dead drives are number 5 and 6 (last 2).

is it possible to recover the data from such case?

Hello ,
How Many Platters Is That SAS Drive Having ,Might Be Some Method You Could Change Heads And Do a Partial Recovery And Have Some Chance of Better Recovery

[Dmitri]

How Many Platters Is That SAS Drive Having ,Might Be Some Method You Could Change Heads And Do a Partial Recovery And Have Some Chance of Better Recovery

Besides very low chances of such recovery, this will require enormous amount of work.
So probably most reasonable approach would be to attempt pulling damaged files to see what's salvageable.

Answering the initial question, generally, RAID 5 can tolerate only one lost drive.

[Amarbir[CDR-Labs]]

How Many Platters Is That SAS Drive Having ,Might Be Some Method You Could Change Heads And Do a Partial Recovery And Have Some Chance of Better Recovery

Besides very low chances of such recovery, this will require enormous amount of work.
So probably most reasonable approach would be to attempt pulling damaged files to see what's salvageable.

Answering the initial question, generally, RAID 5 can tolerate only one lost drive.

Dimitri ,
I Am No Expert in RAID Now "But Situation Will Change In Few Months " ,But i am working Extremely Hard With Mechanical Drive Internals and working out beautiful solutions daily ,So i Believe a Photo of the drive internals will help

[Dmitri]

Dimitri ,
I Am No Expert in RAID Now "But Situation Will Change In Few Months " ,But i am working Extremely Hard With Mechanical Drive Internals and working out beautiful solutions daily ,So i Believe a Photo of the drive internals will help

I didn't mean RAID recovery, it should be pretty doable, I was talking about SAS one.

Anyway, experience is good, if you'd like to go this way, try playing with SCSI/SAS drives. You don't even need damaged ones, working drives will do as well.

[DR-Kiev]

There is always a chance that last drive was assigned as spare drive or they used different raid type , like raid6 or raid10 for example.

[Amarbir[CDR-Labs]]

Dimitri ,
I Am No Expert in RAID Now "But Situation Will Change In Few Months " ,But i am working Extremely Hard With Mechanical Drive Internals and working out beautiful solutions daily ,So i Believe a Photo of the drive internals will help

I didn't mean RAID recovery, it should be pretty doable, I was talking about SAS one.

Anyway, experience is good, if you'd like to go this way, try playing with SCSI/SAS drives. You don't even need damaged ones, working drives will do as well.

Well,
Do Not Worry We Will Nail Then As And When They Arrive ,Already Preparing a Large Section In The Workshop For SAS/SCSI/RAIDS And NAS Drives . No Need To Play With Them As since Seagate Decided To Start The F3 Series Drives They Gave Us The Opportunity To Understand SCSI Arch " Atleast a Bit " ,

PS : Post a Photo Thread starter Please

[northwind]

There is always a chance that last drive was assigned as spare drive or they used different raid type , like raid6 or raid10 for example.

+1
We got a "Raid5" last week, 4 * 3TB Grenada (nice choice for a Raid!), 2 of them down. One of those two with severe platter damage (typical ) and while we were struggling to recover the other one, it hit me. It was a Raid10 and one of the good two drives was developing bad sectors too.
Luckily the stripe part of the Raid was in those two drives.

[jermy]

4 * 3TB Grenada (nice choice for a Raid!)

I have seen it in here there are certain models coming ready to use, with the HDD's inside, I told them to replace them before a disaster

[eazycut]

I agree about the stripe size but in almost all cases the files customers wants back are bigger then the total stripesize x 4. But there will allways be some kind of corruption anyway.