1U K-Server 1500 problems

[Andoreaw]

Hello I have a problem with my 1U server.
Two of its HDDs recently failed, one after the other..
When the problem arised at the beginning the system worked ( I was able to use it, but with a warning message showing up ) but now, after a few days, everything stopped and it just shows a message saying that I have to contact Kaleidescape to buy the replacement disks..

I live in Europe and distributor there has sky rocket prices for these things…

I have one question: has anybody succeeded in having the system accept a normal hdd (not bought from Kaleidescape) in their servers..?
Disks are simply normal “Seagate” hdds, but I know they must be formatted prior to install with the Kaleidescape format system in order for the server to be able to read them…
I was thinking (supposed I can somehow retrieve the datas from this ) to take one of the failed disks and make a bit to bit copy on another one I bought (same brand, same size, but different serial) and then try if on my system… Has anybody tried this and how did it go…? Is there any workaround to make the server recognize a normal hdd …?

Any help would be appreciated…

Thank you

Andrea

 

[andy]

Regardless if you make a bit-for-bit copy, your Kserver will not accept a normal HDD. There are additional "identifiers" it looks for that a normal HDD will not have.

 

[Andoreaw]

Regardless if you make a bit-for-bit copy, your Kserver will not accept a normal HDD. There are additional "identifiers" it looks for that a normal HDD will not have.

I understand. May I ask you what these “identifiers” are..? HDD serial number maybe..? Is there a way to “trick” the system to accept the standard HDD..?

 

[flitebynite]

I understand. May I ask you what these “identifiers” are..? HDD serial number maybe..? Is there a way to “trick” the system to accept the standard HDD..?

My understanding is that it the propitiatory software for the K operating system that is the controlling factor for the HDD's.

 

[jmdls]

At this point, if you have lost TWO drives, I fear that you may have lost all of your content....

 

[Andoreaw]

Yes, the system can’ t be accessed now until I install two working HDDs..

I accidentally found a guy who is selling three working (he says) HDDs cannibalized from a 1U server which has been sold…

I wonder if these “used” HDDs can be installed in my system as well…?
What do you think…?

 

[flitebynite]

Yes, the system can’ t be accessed now until I install two working HDDs..

I accidentally found a guy who is selling three working (he says) HDDs cannibalized from a 1U server which has been sold…

I wonder if these “used” HDDs can be installed in my system as well…?
What do you think…?

If they are a set of disks that have been paired together previously, yes.
If they are from separate disk sets, No.
You also can not add them to an existing set of disks from another server. They are a set and coupled to each other and can not be intermixed unless they are re-initialized by K. And they will only do this with disks that remain under warranty. Unless things have changed.
I hope this makes sense.
I have learned the hard way about buying used HDD's.
Buyer beware...

 

[andy]

When an HDD fails, a 1U server enters a degraded state where it continues functioning and uses parity information to calculate missing data. However, if a 2nd HDD fails when the server is in this state, missing data can no longer be calculated (too many bits are missing) and the file system will cease to function suffering a catastrophic failure.

If there is a catastrophic failure, adding a standalone HDD will do no good since the file system is no longer working (and will not be able to add the HDD and initiate a rebuild). Unfortunately, if your server is in this state, the file system cannot be salvaged and a new disk array/file system would need to be installed.

Now, there is a feature in KEAOS that if when an HDD fails and one of the remaining HDDs in the disk array is "unused" (meaning it is currently empty AND never had data written to it), the server will shrink the file system and use the unused HDD to rebuild the missing data (from the failed HDD). Assuming the rebuild completes successfully, it is possible to then have a 2nd HDD fail without the file system suffering a catastrophic failure.

If there was an unused HDD and your server was able to finish a rebuild before the 2nd HDD failed, then I'd expect your server to still function, but in a degraded state. If you install a standalone HDD with your server in this state, the file system will add it and then use it to rebuild the missing data.

If you are not sure what state your server/file system is in, you are best off contacting K support. If your server was online when all of the events occurred, their logging is robust enough to help you determine what happened. Good luck!

 

[Andoreaw]

ah

When an HDD fails, a 1U server enters a degraded state where it continues functioning and uses parity information to calculate missing data. However, if a 2nd HDD fails when the server is in this state, missing data can no longer be calculated (too many bits are missing) and the file system will cease to function suffering a catastrophic failure.

If there is a catastrophic failure, adding a standalone HDD will do no good since the file system is no longer working (and will not be able to add the HDD and initiate a rebuild). Unfortunately, if your server is in this state, the file system cannot be salvaged and a new disk array/file system would need to be installed.

Now, there is a feature in KEAOS that if when an HDD fails and one of the remaining HDDs in the disk array is "unused" (meaning it is currently empty AND never had data written to it), the server will shrink the file system and use the unused HDD to rebuild the missing data (from the failed HDD). Assuming the rebuild completes successfully, it is possible to then have a 2nd HDD fail without the file system suffering a catastrophic failure.

If there was an unused HDD and your server was able to finish a rebuild before the 2nd HDD failed, then I'd expect your server to still function, but in a degraded state. If you install a standalone HDD with your server in this state, the file system will add it and then use it to rebuild the missing data.

If you are not sure what state your server/file system is in, you are best off contacting K support. If your server was online when all of the events occurred, their logging is robust enough to help you determine what happened. Good luck!

Ok thank you for the detailed explanation.
I think I am the situation where two HDDs failed one after the other, and the one that failed before didn’ t have the possibility to do a rebuild. In fact the system is completely unusable now..

As per what flitebynite wrote above, file systems cannot be “mixed” so I won’ t be able to use a disk taken from another 1U server with the working disks inside my 1U.
But ( if I understand correctly…), supposed I can find 4 x used 6Tb HDDs taken from another 1U (which were paired to work togheter), I should be able to use those in my 1U, as long as I don’ t mix them with the disks that came with my 1U, is that correct…?
In that case I will take the chance and buy those used disks, hoping that they work on my server as well…

 

[flitebynite]

ah

Ok thank you for the detailed explanation.
I think I am the situation where two HDDs failed one after the other, and the one that failed before didn’ t have the possibility to do a rebuild. In fact the system is completely unusable now..

As per what flitebynite wrote above, file systems cannot be “mixed” so I won’ t be able to use a disk taken from another 1U server with the working disks inside my 1U.
But ( if I understand correctly…), supposed I can find 4 x used 6Tb HDDs taken from another 1U (which were paired to work togheter), I should be able to use those in my 1U, as long as I don’ t mix them with the disks that came with my 1U, is that correct…?
In that case I will take the chance and buy those used disks, hoping that they work on my server as well…

You understand correctly about the 4x6tb disk set...