N7700 Adding New Discs

I have 5 x 1TB Discs in RAID 5 configuration, all working fine. I then added 2 additional 1TB drives with the intent of expanding capacity.

So I selected the Migrate RAID. No option to change the type of RAID I could see. Then I selected the new drives, and got error messages about the RAID size not being correct. After playing around I found you have to migrate one drive at a time - so a slow process.

My quesion: am I correct that you have to migrate one at a time, rather than selecting both new drives at the same time? Any way round this?

Dear mnorth,

Inorder to expand your RAID capacity, you first need to a RAID migration.
If you currently have RAID 5, you will not be able to migrate to RAID 6,
however, you can migrate the two new disks at the same time to RAID 5.

Before you migrate, please click here and get the latest firmware for N7700 v2.01.09

_____________________________

Official Thecus Support Representative

Thanks for the advice. I could not get the RAID migrate to work selecting both drive 6 and 7 at the same time, only one. So I started with one new disc.

But, it did not go as planned. I have the latest firmware, but during the migrate (after nearly 20 hours!) the 7700 started beeping, the display showed Degraded RAID, and I could not access the RAID status via the web interface.

I restarted the device and it came up with no RAID at all (all data lost but I have a back-up). So now I am formatting a RAID to the full capacity from scratch - and ETA is under 5 hours. There were no logs to show what had happened.

So, I conclude that its quicker and safer to start from scratch rather than trying to migrate a RAID.

And it shows how important it is to back-up the date before fiddling with the RAID.

The Saga continues - the RAID degraded again, so I have now set the Western Digital Time-Limited Error Recovery (TLER) to 7 ms, in the hope this stops the RAID falling over. I am rebuilding the RAID again - takes about 4 hours each time.

This time I was about when the alarm went off to alert me, so I was able to identify which disc had been dropped from the RAID, previously the whole device hung, and I lost the log and data!

I wish there was an option to have the alarm not sounding constantly when degraded though!

Further update later - but so far I have not got 7 WD x 1Tb drives to work for more than a couple of days.

Correction - 7 seconds, not 7 ms.

The RAID rebuild kept falling over at 69.9%, with a error on Disc 1. Ran WD diagnostics on the disc abd it passed. However, replaced the disc with a new one, and its now working again.

So I am wondering what errors, which are not detected by WD diagnostics are causing problems with the N7700, especaially as before I tried to migrate the RAID to the two additional drives, I had no issues at all. Wierd!