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ReadyNAS Duo v1 resynch hang.
After creating a new share on my RN202 I went on and created a rsync backup job on the Duo. I saw that snapshots needed to be excluded, so cancelled the backup job. The Duo advised that I should re...
2ndNAS wrote:
According to WD diagnostic tool both disks are fine.
I suppose the next option is Reinstall firmware and/or Reset to factory defaults?
I'd probably just do the factory default.
You could also try just reinserting one disk (in its original slot) and booting up.
- If that works, see if the data is there. If it is, hot-insert the second disk and wait for the resync.
- If not, power down and try the other disk (by itself).
If both fail, just move on to the factory default.
I do use the older SW and have not found problems with old disks.
A new disk is on order, I'm just trying to learn about this error. Do you know if my Performance Options might have any influence on the hang:
Disable full data journaling (not ticked)
Disable journaling (ticked)
Enable fast CIFS writes (ticked)
Again, thanks for your help.
2ndNAS wrote:
Do you know if my Performance Options might have any influence on the hang:
Disable full data journaling (not ticked)
Disable journaling (ticked)
Enable fast CIFS writes (ticked)
It shouldn't. The resync is just the RAID re-mirroring the two disks (copying each sector from one to the other in the case or RAID-1).
2ndNAS wrote:
I do use the older SW and have not found problems with old disks.
And you also used the full write-zeros test in Lifeguard?
Also what disks are you using? Many new drives 2 TB and under are SMR. They can have very slow sustained write times, so operations like resync could take quite a while.
I used the FULL erase function, but I don't know the kind of data it writes.
My disks are WD20EFRX and I have spend some time educating myself about the difference between WD20EFAX and WD20EFZX, and then what is CMR vs SMR. I suppose the compatibility-list is no longer updated, so I have chosen to stay with the CMR version.
Thanks again for your help.
2ndNAS wrote:
I used the FULL erase function, but I don't know the kind of data it writes.
It zeros the disk.
2ndNAS wrote:
I suppose the compatibility-list is no longer updated,
Very true. I always recommend NAS-purposed CMR drives for the Duo and NV+ models. WD Red Plus (not Reds) and Seagate IronWolf are good choices. Enterprise-class drives are also fine, but IMO overkill, given the limited performance of these particular models.
Note that the WD20EFRX is CMR (and is now branded as a WD Red Plus).
2ndNAS wrote:
what is CMR vs SMR.
See https://en.wikipedia.org/wiki/Shingled_magnetic_recording
PMR is an older name for CMR (for a specific CMR technology).
The general issue with SMR is that writing to track X destroys the data on track X+1. That creates a rippling
- read track X+1, write track X,
- read track X+2, write track X+1
- read track X+3, write track X+2
- ...
That continues until you reach the end of the SMR zone (where there is an unused track). The manufacturers overcome the obvious write performance issue with a lot of cache and attention to the caching algorithm. But sustained writes will overhelm that eventually, and you will always end up with glacially slow write performance at some point.
Best not to use these drives with RAID in any form. Both WD and Seagate are now identifying SMR/CMR on their datasheets.
2ndNAS wrote:
WD20EFAX and WD20EFZX,
Both are SMR, so I don't recommend either.
In general, assume any hard drive <= 6 TB is SMR unless you have manufacturer specs that say otherwise.
2ndNAS wrote:
Are you sure WD20EFZX is SMR?
Sorry - I misread the number. All WD Red Plus drives are CMR, so it is fine.
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