NETGEAR is aware of a growing number of phone and online scams. To learn how to stay safe click here.
Forum Discussion
Solved
X-RAID with one disk offsite?
For 8 years with my predecessor RND210, used soley for Mac's TimeMachine, I have successfully stored one disk offsite, then periodially returned it to resync, then returned it to offsite. Of course,...
Well, I suspect you won't buy my reasons for not doing this either, as I use other NAS for backup. I agree that requires more equipment, but I like the convenience and the fact that it is fully automated.
If you only use two disks, then if the disk already in the NAS fails (or is detected as failed) during the resync you will lose the data on both disks. So that is definitely a risky strategy.
If you use three disks (rotating two for backup), it is safer. But personally I'd rather rotate USB disks instead (or perhaps use a USB dock, rotating two internal drives). That eliminates the windows of poor performance during resync, and any possibility of damaging the SATA backplane or the internal disk(s). It also allows more frequent backups (especially if you use incremental rsync). One additional benefit is that it gives you a backup you can access from a PC (assuming you format the external disks as NTFS). So if the NAS itself fails, you don't need to buy a new one to regain access to your data.
JeffoFitts wrote:
Do backups pause while resyncing? Does this cause more drive thrashing than it would otherwise?Backups will not pause during resync, but the NAS will be much slower.
With RAID-1, the resync involves reading every single sector on first disk, and writing it to the second disk. This is done in the background. So any access of the NAS (read or write) will create disk thrashing. It will also further slow the resync (because it is a background activity).
In most cases you won't uncover a disk problem (for instance a bad sector) until the system tries to read or write to it. So it is far more likely that the system will detect a disk failure during resync than at any other time - because the system is reading (or writing) every sector on the drive. As I said above, If it's a read failure (50-50 chance it will be), the resync fails and you lose the data on both disks.
JeffoFitts wrote:
Volume: Volume data is resynced. [took 4 hours after 26 hour disk separation]The time of separation isn't relevant. The resync copies every sector, it is not an incremental update.
If it only took 4 hours, then your disks must be pretty small (1 TB?). So another disaster recovery option might be to use cloud storage. Google Drive perhaps.
Well, I suspect you won't buy my reasons for not doing this either, as I use other NAS for backup. I agree that requires more equipment, but I like the convenience and the fact that it is fully automated.
If you only use two disks, then if the disk already in the NAS fails (or is detected as failed) during the resync you will lose the data on both disks. So that is definitely a risky strategy.
If you use three disks (rotating two for backup), it is safer. But personally I'd rather rotate USB disks instead (or perhaps use a USB dock, rotating two internal drives). That eliminates the windows of poor performance during resync, and any possibility of damaging the SATA backplane or the internal disk(s). It also allows more frequent backups (especially if you use incremental rsync). One additional benefit is that it gives you a backup you can access from a PC (assuming you format the external disks as NTFS). So if the NAS itself fails, you don't need to buy a new one to regain access to your data.
JeffoFitts wrote:
Do backups pause while resyncing? Does this cause more drive thrashing than it would otherwise?
Backups will not pause during resync, but the NAS will be much slower.
With RAID-1, the resync involves reading every single sector on first disk, and writing it to the second disk. This is done in the background. So any access of the NAS (read or write) will create disk thrashing. It will also further slow the resync (because it is a background activity).
In most cases you won't uncover a disk problem (for instance a bad sector) until the system tries to read or write to it. So it is far more likely that the system will detect a disk failure during resync than at any other time - because the system is reading (or writing) every sector on the drive. As I said above, If it's a read failure (50-50 chance it will be), the resync fails and you lose the data on both disks.
JeffoFitts wrote:
Volume: Volume data is resynced. [took 4 hours after 26 hour disk separation]
The time of separation isn't relevant. The resync copies every sector, it is not an incremental update.
If it only took 4 hours, then your disks must be pretty small (1 TB?). So another disaster recovery option might be to use cloud storage. Google Drive perhaps.
NETGEAR Academy
Boost your skills with the Netgear Academy - Get trained, certified and stay ahead with the latest Netgear technology!
Join Us!
