RAID 1 and Reliability

[Timaphillips]

At my small business office, we currently use a Dlink external NAS with an FTP server built in. I have it set up with RAID one on 2 HDD's. It's a so-so systems for our needs but cost-effective. Currently, my computer outputs all CAD/3D files for our architectural work and through NTI shadow, my "work" folder gets copied continually (although it doesn't work, so I have to manually start it) to the external NAS. On the other two computers in the office, they work directly off of the NAS. I don't really like the solution since only one person can work on a file at a time and if it crashes, they lose all their work since they usually forget to save the copy their working on to their desktop. And now that I've gone a little bit off track, I'll get to the point. How reliable is the RAID 1 on the two HDD's? If one fails, I understand the other is a close and it's hopefully as simple as a hot swap. But if one STARTS to fail, wouldn't the other clone its missed files or clone its errors as well?

 

[Baez]

RAID 1 does not work like that. You're thinking in the mindset of the old IDE Master/Slave setup. What RAID 1 does is make both drives equal in every way. Neither is the master or slave in this case. They both copy the files independently of each other. One does not copy the files from the other. Therefore if one drive starts to fail, the other drive will still copy all files properly.

 

[Timaphillips]

RAID 1 does not work like that. You're thinking in the mindset of the old IDE Master/Slave setup. What RAID 1 does is make both drives equal in every way. Neither is the master or slave in this case. They both copy the files independently of each other. One does not copy the files from the other. Therefore if one drive starts to fail, the other drive will still copy all files properly.

Well that's a relief.

 

[kmote]

Yes, in RAID 1 the controller effectively writes to both drives simultaniously.
I don't know if you are able to on your dlink box but something you might think about for the future is running a CVS (or similar) server. This would solve your issue with concurrent access etc.

 

[oldskool]

You can also think of RAID 1 as "mirroring". That is how I remember what RAID 1 is.