2011-07-04 01:53 AM
We're about to implement our NetApps in our Solaris environment and I was wondering if there were any guidelines with regards zpool configuration. In particular, I was wondering whether to mirror the disks in the pool or not. From the Solaris Internals Best Practices wiki: "For production environments, configure ZFS so that it can repair data inconsistencies. Use ZFS redundancy, such as RAIDZ, RAIDZ-2, RAIDZ-3, mirror, regardless of the RAID level implemented on the underlying storage device. With such redundancy, faults in the underlying storage device or its connections to the host can be discovered and repaired by ZFS."
This seems to be pretty clear that I should use mirroring. I'm hoping for some links on specific best-practices with Solaris (containers,ZFS) and NetApp.
2011-07-04 08:04 AM
The tricky bit is that ZFS is essentially what you would use if you wanted to build a resilient filer on the cheap and you didn't have a NetApp handy. There are no "best practice" documents as far as I can tell, probably because the combination is rather rare - the features of the two overlap so significantly that you would seldom find a scenario where both are intended to be used at the same time.
What services are you implementing on your Solaris boxen ?
2011-07-04 08:34 AM
"ZFS is essentially what you would use if you wanted to build a resilient filer on the cheap and you didn't have a NetApp handy" - err... if you are installing Solaris UNIX your choices are essentially UFS and ZFS. Essentially, whenever you're going to assign a NetApp LUN to a Solaris UNIX machine via FC, the chances are you're going find an overlap. I'm not sure what you mean about using ZFS for cheap resilient filer - you're probably referring to an i386 implementation of Solaris (possibly even using OpenSolaris). I'm using ZFS as part of enterprise Solaris on SPARC architecture - kicking it old school - definitely not on the cheap side.
My Solaris boxes run a variety of applications, including Oracle and Sybase. I'm not talking about Solaris in a space where it is competing with NetApp but in a situation where the NetApp is providing the SAN storage to a Solaris machine.
2011-07-18 06:37 AM
Managed to get a document from someone on ZFS Best Practices with NetApp (TR-3603 June 2007). It says that I should definitely keep my ZFS RAID in place (mirroring for best performance). Also has a number of other useful titbits, like telling you how to align your WAFL and ZFS blocks.
2011-07-18 02:11 PM
I'm not sure what ZFS raid solutions are going to get you except more expensive storage. If you mirrored to 2 filers, then perhaps a bit more resiliance, but that won't be cheap either. ZFS was not a terribly good idea for Oracle a couple of years ago, and I haven't followed along enough to know if that has changed much. It uses a ton of memory and is nowhere as mature as UFS or VxFS or even NFS, but it has a lot of hype behind it. ZFS snapshots were pretty lame and mirroring was 'scp', more or less. Not exactly an enterprise solution. Not sure how well any of this works with SnapDrive...
If you don't use the EFI lun type, you are probably going to beat up your filers as well with a lot of extra I/O.
2011-07-18 02:42 PM
You could attach a copy of it and let us have a look at it. Doesn't show up after a cursory Google.
Forced to concur with the other guys here. Using ZFS mirroring on top of a resilient storage array (whether it is NetApp or anything else) is just a waste of disk space. The V-Series is WAFL on top of third party resilient storage, NetApp don't recommend adding another layer of resiliency there .. why would they do so for ZFS ? Something ain't right.
It would hardly be sensible to use UFS of course, but surely it would be sufficient to simply add the LUNs to a zpool and use plain old concatenation. ONTAP will protect your LUNs.
2011-07-18 02:49 PM
ZFS was/is a fine idea - it is a clean reimplementation of WAFL, after all. RAM and disk is cheap, so the argument that you can solve storage problems with lots and lots of caching rather than tight performance engineering sounds valid enough to me.
ZFS snapshots and mirroring are just like those of WAFL. The problem is not ZFS itself, but simply that the tools haven't been built around it to properly leverage those features. Maturity and ecosystem are the issues here, not technical deficiency. Sadly, Oracle don't seem to be minded to change that. I rather suspect that btrfs will come along and upstage it in a couple of years time due to sheer brute force adaptation on the major Linux distros.