Linux disc cloning help

[ted_b]

I am reaching out to my CA brethren for some help.  I had a catastrophic Synology NAS crash this past weekend....I have a DS1513+ with attached DX513 (nine disks total) and have SHR raid set up, which allows for one disk failsafe.  HOWEVER, I hit the jackpot, I had TWO disks fail within an hour of each other (should have bought some lottery tickets with those kinds of odds!), causing my system of 19TB of data (stereo, multichannel, SACD ISOs  are the important stuff) to crash!!  Argh.

 

To make a long, ugly story shorter I have been able to scrape together about half of my music data, and am relying on the fact that I still have access to the NAS files, albeit at kbs/sec due to the reading and re-reading of bad sectors on two disks.  This is untenable as it will take months at this rate, and those fragile discs may die in the meantime.

 

A solution is to fully clone disk 1 and disk 4, then replace the bad hard drives with the cloned ones, and then continue my backup copying, this time at near normal speeds.  I will also then add a tenth drive and change RAID to SHR-2 which allows TWO disk failure.  That's the plan, blessed by Synology.

 

So.....anybody out there familiar with cloning ex4 (Linux) drives?  I am a Windows person, and although I have found, via freeware, that I can see ex4 drives (I had a subset of copied music in ex4 backup drives and copied them over to my NTFS drives)...I cannot clone ex4 drives from Windows, nor do I necessarily want to do this, being that I am a newbie in this realm.

 

Any ideas would be welcome.  Thanks.

[mansr]

Toss the bad drives, buy new ones, and restore from backups. Oh, what backups?

[ted_b]

Thanks.  That's very helpful right now.

[mjt5282]

your plan requires very careful use of the elevated "root" permissions in order to clone the dying drives. The linux "dd" command is used to clone drives (see: https://wiki.archlinux.org/index.php/disk_cloning ) .   The command itself is simple, but you have to be exact and specific with the command's arguments, otherwise you can destroy a healthy drive by cloning the wrong drives.I am not familiar with Synology (my first nas was a Infrant (now ReadyNAS) I eventually built my own NAS and run ZFS raidz2 with it. I am familiar with the BSD/Linux command line, though. Feel free to PM me if you need advice or help.

[ted_b]

Thanks.  I stumbled upon ddresue command (supposed to run it a few times, etc) but will not even attempt before I PM you with my command line syntax.  I still need to buy the replacement drives so will be a few days.  And I am looking for my AudioLinux boot USB to even get there.  Thx again.

[Dan Gravell]

If you haven't done already, I'd advise you ask on Synology sites...

[BobSherman]

On 11/2/2017 at 8:30 AM, ted_b said:

I am reaching out to my CA brethren for some help.  I had a catastrophic Synology NAS crash this past weekend....I have a DS1513+ with attached DX513 (nine disks total) and have SHR raid set up, which allows for one disk failsafe.  HOWEVER, I hit the jackpot, I had TWO disks fail within an hour of each other (should have bought some lottery tickets with those kinds of odds!), causing my system of 19TB of data (stereo, multichannel, SACD ISOs  are the important stuff) to crash!!  Argh.

 

To make a long, ugly story shorter I have been able to scrape together about half of my music data, and am relying on the fact that I still have access to the NAS files, albeit at kbs/sec due to the reading and re-reading of bad sectors on two disks.  This is untenable as it will take months at this rate, and those fragile discs may die in the meantime.

 

A solution is to fully clone disk 1 and disk 4, then replace the bad hard drives with the cloned ones, and then continue my backup copying, this time at near normal speeds.  I will also then add a tenth drive and change RAID to SHR-2 which allows TWO disk failure.  That's the plan, blessed by Synology.

 

So.....anybody out there familiar with cloning ex4 (Linux) drives?  I am a Windows person, and although I have found, via freeware, that I can see ex4 drives (I had a subset of copied music in ex4 backup drives and copied them over to my NTFS drives)...I cannot clone ex4 drives from Windows, nor do I necessarily want to do this, being that I am a newbie in this realm.

 

Any ideas would be welcome.  Thanks.

deleted

[Samuel T Cogley]

On 11/2/2017 at 5:30 AM, ted_b said:

I am reaching out to my CA brethren for some help.  I had a catastrophic Synology NAS crash this past weekend....I have a DS1513+ with attached DX513 (nine disks total) and have SHR raid set up, which allows for one disk failsafe.  HOWEVER, I hit the jackpot, I had TWO disks fail within an hour of each other (should have bought some lottery tickets with those kinds of odds!), causing my system of 19TB of data (stereo, multichannel, SACD ISOs  are the important stuff) to crash!!  Argh.

 

To make a long, ugly story shorter I have been able to scrape together about half of my music data, and am relying on the fact that I still have access to the NAS files, albeit at kbs/sec due to the reading and re-reading of bad sectors on two disks.  This is untenable as it will take months at this rate, and those fragile discs may die in the meantime.

 

A solution is to fully clone disk 1 and disk 4, then replace the bad hard drives with the cloned ones, and then continue my backup copying, this time at near normal speeds.  I will also then add a tenth drive and change RAID to SHR-2 which allows TWO disk failure.  That's the plan, blessed by Synology.

 

So.....anybody out there familiar with cloning ex4 (Linux) drives?  I am a Windows person, and although I have found, via freeware, that I can see ex4 drives (I had a subset of copied music in ex4 backup drives and copied them over to my NTFS drives)...I cannot clone ex4 drives from Windows, nor do I necessarily want to do this, being that I am a newbie in this realm.

 

Any ideas would be welcome.  Thanks.

 

 

Hi Ted

 

This is what I would do:

 

Make a bootable USB stick with Clonezilla.  Then acquire a SATA/USB enclosures (if your disks are 4TB or larger, make sure the enclosure supports this).  Then, one by one, boot from the Clonezilla USB stick and clone the degraded drives to new drives.

 

This is pretty straight forward.  I'll be happy to give you more detailed directions if you need them.

[ted_b]

Thanks for the help.  I am now down to one large folder (2.8TB) left to copy via the very slow boat, or do the cloning.  Risk of former is that the discs die during that 2 week copy.

 

Bob, as per earlier note, Synology has done what they can do remotely.  Here is their latest response:

"Both options involve risks. Cloning will not be able to read the bad sectors and potentially not clone all of your data. With you current drives you of course run the risk of them failing.

Ideally, you will want to proceed with backing up using the current drives, I cannot say how long it will take to clone, but if you think it is a reasonable time, clone the drives in case the current ones fail and you have done enough research to understand the process to be confident in cloning. Then proceed to back up as you were and if the drives fail completely you can continue using the clones."

 

How long does cloning a 3TB drive take?

[Samuel T Cogley]

34 minutes ago, ted_b said:

Thanks for the help.  I am now down to one large folder (2.8TB) left to copy via the very slow boat, or do the cloning.  Risk of former is that the discs die during that 2 week copy.

 

Bob, as per earlier note, Synology has done what they can do remotely.  Here is their latest response:

"Both options involve risks. Cloning will not be able to read the bad sectors and potentially not clone all of your data. With you current drives you of course run the risk of them failing.

Ideally, you will want to proceed with backing up using the current drives, I cannot say how long it will take to clone, but if you think it is a reasonable time, clone the drives in case the current ones fail and you have done enough research to understand the process to be confident in cloning. Then proceed to back up as you were and if the drives fail completely you can continue using the clones."

 

 

I agree that cloning will skip bad sectors. Probably not what you want.

 

Quote

How long does cloning a 3TB drive take?

 

Depending on the RPM speed of your drive(s) and the interface you're using (You want USB3 for sure in external enclosures), 2-6 hours.