So is an SSD OK in the array or not?

[craigr]

I have had an SSD in my array since day one mostly for data that my theater media wall uses (tons of small files and the drive has to be accessed and "spun up" often).  It's only a 64gig drive.  I just stumbled on this thread where the question is brought up as to whether or not data can be properly rebuilt if a drive is lost if an SSD is part of the array:

 

https://lime-technology.com/forum/index.php?topic=42961.0

 

They work for normal read and write use, the question that has yet to be resolved that I have seen is if areas of the filesystem that are trimmed are still accurate for use in rebuilding other disks. I've only got a vague understanding of what is involved, but I think the issue is that if a SSD aware file system tells the drive that a certain area on the drive is no longer needed because the file(s) there have been deleted, the drive could possibly alter data that may be needed to reconstruct other drives.

 

Hopefully dual parity can be used to flesh out whether or not it's an issue, because we can use 1 SSD in the array and still not torpedo a recovery.

 

I could be way off base, I haven't seen anything about the issue in a while, so it may be a non-issue.

 

So could someone please tell me if my data is safe or not with an SSD drive as part of my array?  If not I will have to figure out an alternative quick.

 

Thanks,

craigr

[JonathanM]

Email Tom at limetech and ask directly.

[craigr]

Just sent an email to support:

 

I have always had an SSD as part of my array drives that takes part in my “Media” user share.  The SSD contributes the data for my media wall and consists of lots of small files that need to be read back quickly.

 

I just stumbled on a thread in the forum where the question is posed asking if SSD drives as part of the array is unsafe because areas of the file system that are trimmed may not be accurate for use in rebuilding other disks.  If a data drive fails, it was said that the array may not be able to accurately rebuild the failed drive because of the SSD.  This thread is located here:

 

https://lime-technology.com/forum/index.php?topic=42961.0

 

I asked this question in a new thread and was told to email you.  Here is my thread.

 

https://lime-technology.com/forum/index.php?topic=42986.0

 

So could you please let me know if SSD drives are safe to have in the array?  If not I will have to change up my array quickly to get out of danger.

 

One other point of reference; the SSD is now formatted as btrsf which I understand natively supports TRIM (the rest of my data drives are now XFS).

 

Thanks and kind regards,

 

We will see.

 

craigr