Jim Davis jdavis@CS.Arizona.EDU writes:
Potential plan: buy a shelf of 9GB disks, put it on toaster A, move a shelf of 4GB disks to toaster B, keeping all of the toaster A data on toaster A. Toaster B ends up with an empty file system on its 4GB disk shelf.
Now the mechanics of the move are a little unclear to me. Presumably we hook up the 9GB shelf to toaster A and 'raid fail' each 4GB disk in the shelf we want to move? But there will be 5 9GB data disks, since we have to burn one as a hot spare and one becomes the new parity disk. Will there be a problem with having 7 disks to move data from, but only 5 disks to move data to? There would be enough GBs on the 5 9GB disks, but...
Yes, it won't work as you suspect (unless, of course, you do a backup-restore cycle) because the total number of disks in a NetApp RAID group can't be reduced, even if the capacity is increased.
You can get back your 4GB spare, since you only need one spare. The spare only has to be the same size of the largest data disk in the system. If you have a 9GB spare and a 4GB disk fails, you end up adding 5 GB to the filesystem when the spare replaces the failed disk.
Dan
Now the mechanics of the move are a little unclear to me. Presumably we hook up the 9GB shelf to toaster A and 'raid fail' each 4GB disk in the shelf we want to move? But there will be 5 9GB data disks, since we have to burn one as a hot spare and one becomes the new parity disk. Will there be a problem with having 7 disks to move data from, but only 5 disks to move data to? There would be enough GBs on the 5 9GB disks, but...
Yes, it won't work as you suspect (unless, of course, you do a backup-restore cycle) because the total number of disks in a NetApp RAID group can't be reduced, even if the capacity is increased.
It also won't work because you can't increase the size of a disk once it's on the RAID group.
You can get back your 4GB spare, since you only need one spare. The spare only has to be the same size of the largest data disk in the system. If you have a 9GB spare and a 4GB disk fails, you end up adding 5 GB to the filesystem when the spare replaces the failed disk.
No, you end up putting 4GB on a 9GB drive and getting no more space in the file system than you had before. (If there are multiple spares in the system, the smallest one which is large enough to replace the failed drive will be used.)
-- Karl
Ah well, so much for that plan!
Is there a way to move a 4GB shelf without doing a full dump and restore of the system -- which we've never tried, and our tape guy estimates the restore would take about 70 hours...
Ah well, so much for that plan!
Is there a way to move a 4GB shelf without doing a full dump and restore of the system -- which we've never tried, and our tape guy estimates the restore would take about 70 hours...
You might want to contact your local sales office and ask about BareMetal Migrate.
mikef
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Daniel Quinlan -
Jim Davis -
kls＠netapp.com -
Mike Federwisch