Our company (in its wisdom) has decided that all "critcal" data must be on mirrored filesystems, not on raid.
On filers, if you set the raidsize to 2, you effectively get a mirrored volume.
Does anyone do this? Does it cause a performance problem? Is there a limit on the number of raid groups in a volume?
- Bruce
why not use the raid group plex mirroring already provided in OnTap ? from the 6.4.1 "vol" man page:
vol create volname [ -r raidsize ] [ -l language_code ] [ -f ] [ -m ] [ -w ] [ -n ] { ndisks[@size] | -d disk1 [ disk2 ... ] [ -d disk1 [ disk2 ... ] ] }
Creates a new volume with the name volname. The volume name can contain letters, numbers, and the underscore character(_), but the first character must be a letter or underscore. You can create up to 200 volumes on each filer.
...
The -m option can be used to specify that the new volume be mirrored (have two plexes) upon creation. If this option is given, then the indicated disks will be split across the two plexes. By default, the new volume will not be mirrored.
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means you need more spindles, but that's what mirrors are all about.
-skottie
Bruce Arden wrote:
Bruce, Your company is a NetApp Salesman's dream. Even mirrored pairs don't protect you against double disk errors in the same pair. I would recommend you look at implementing mirrored raid groups on local drives. This is done at driver level and is not to be confused with snap mirror. Under this scenario your traditional raid-4 groups, 4-7 drives each, are driver mirrored to another raid-4 group on the same machine. No TCP-IP involvement. With this scenario you can survive a triple disk failure. You need slightly more disk than straight mirrored pairs but you get performance, complete off-line volumes that are still raid protected, etc.... Re-syncing is pretty straight forward too when you break the local mirror and join them again. This feature/scenario is one of NetApp's key metro recovery features.
The only thing you need now is a can full of money....
Hunter M. Wylie 21193 French Prairie Rd Suite 100 St. Paul, Oregon 97137-9722 Bus: 866-367-8900 FAX: 503-633-8901 Cell: 503-880-1947
-----Original Message----- From: owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com] On Behalf Of Bruce Arden Sent: Wednesday, July 23, 2003 10:02 AM To: toasters@mathworks.com Subject: Mirroring using raidsize=2
Our company (in its wisdom) has decided that all "critcal" data must be on mirrored filesystems, not on raid.
On filers, if you set the raidsize to 2, you effectively get a mirrored volume.
Does anyone do this? Does it cause a performance problem? Is there a limit on the number of raid groups in a volume?
- Bruce
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Bruce Arden -
Hunter Wylie -
Skottie Miller