[zfs-discuss] ZFS: A general question
Hello everyone, I'm new to ZFS and OpenSolaris, and I've been reading the docs on ZFS (the pdf The Last Word on Filesystems and wikipedia of course), and I'm trying to understand something. So ZFS is self-healing, correct? This is accomplished via parity and/or metadata of some sort on the disk, right? So it protects against data corruption, but not against disk failure. Or is it the case that ZFS intelligently puts the parity and/or metadata on alternate disks to protect against disk failure, even without a raid array? Anyway you can add mirrored, striped, raidz, or raidz2 arrays to the pool, right? But you can't effortlessly grow/shrink this protected array if you wanted to add a disk or two to increase your protected storage capacity. My understanding is that if you want to add storage to a raid array, you must copy all your data off the array, destroy the array, recreate it with your extra disk(s), then copy all your data back. I like the idea of a protected storage pool that can grow and shrink effortlessly, but if protecting your data against drive failure is not as effortless, then honestly, what's the point? In my opinion, the ease of use should be nearly that of the Drobo product. Which brings me to my final question: is there a gui tool available? I can use command line just like the next guy, but gui's sure are convenient... Thanks for your help! -Steve This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] ZFS: A general question
OK so in my (admittedly basic) understanding of raidz and raidz2, these technologies are very similar to raid5 and raid6. BUT if you set up one disk as a raidz vdev, you (obviously) can't maintain data after a disk failure, but you are protected against data corruption that is NOT a result of disk failure. Right? So is there a resource somewhere that I could look at that clearly spells out how many disks I could have vs. how much resulting space I would have that would still protect me against disk failure (a la the Drobolator http://www.drobo.com/drobolator/index.html)? I mean, if I have a raidz vdev with one disk, then I add a disk, am I protected from disk failure? Is it the case that I need to have disks in groups of 4 to maintain protection against single disk failure with raidz and in groups of 5 for raidz2? It gets even more confusing if I wanted to add disks of varying sizes... And you said I could add a disk (or disks) to a mirror -- can I force add a disk (or disks) to a raidz or raidz2? Without destroying and rebuilding as I read would be required somewhere else? And if I create a zpool and add various single disks to it (without creating raidz/mirror/etc), is it the case that the zpool is essentially functioning like spanning raid? Ie, no protection at all?? Please either point me to an existing resource that spells this out a little clearer or give me a little more explanation around it. And... do you think that the Drobo (www.drobo.com) product is essentially just a box with OpenSolaris and ZFS on it? This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] ZFS: A general question
Sooo... I've been reading a lot in various places. The conclusion I've drawn is this: I can create raidz vdevs in groups of 3 disks and add them to my zpool to be protected against 1 drive failure. This is the current status of growing protected space in raidz. Am I correct here? This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] ZFS: A general question
THANK YOU VERY MUCH EVERYONE!! You have been very helpful and my questions are (mostly) resolved. While I am not (and probably will not become) a ZFS expert, I now at least feel confident that I can accomplish what I want to do. My last comment on this is this: I realize that ZFS is designed and intended for Enterprise use, but it also has many useful features that home and soho users appreciate. That being said, I feel that it still will leave most casual home and soho users a bit confused and wishing for other features (especially ease of use). If Sun released a software alternative to the Drobo product, I feel certain that they would be able to very successfully market a product like this to home and soho users. Heck, I would buy such a piece of software (from Sun) in a hot second. Plus, if they based it off of ZFS and just hid most of the configuration options so that your pools were automatically configured with single parity (or mirror for 2 drive setups) -- then added the expand-o-matic raidz feature, add a shrink feature, and add the ability to better utilize space on differently sized drives -- it would be awesome, and a good part of the work would already be done (ie, ZFS). It would be far superior to Drobo, and could probably undercut Drobo significantly on price point. Then it would truly be the holy grail of file systems. In fact, depending on the license of OpenSolaris/ZFS, I wonder if a group of independent developers could package up Vbox, OpenSolaris, a modified ZFS, and a setup/admin utility to create such a product... that would be cool. Again, the heavy lifting would be modifying raidz so that it could expand/shrink/better utilize space on differently sized drives. This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
