Re: [zfs-discuss] Where is the ZFS configuration data stored?
Does it matter if the /dev names of the partitions change (i.e. from / dev/dsk/c2t2250CC611005d3s0 to another machine not using sun hba drivers with a different/shorter name??) thanks keith If the file does not exist than ZFS will not attempt to open any pools at boot. You must issue an explicit 'zpool import' command to probe the available devices for metadata to re-discover your pools. ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Re: Re: please remove my ignorance of raiding andmirroring
On Oct 1, 2006, at 11:24 PM, Anton B. Rang wrote: I was perhaps slightly hasty; RAID-5 is more efficient than a 2- disk mirror for reads, but RAID-10 (striping mirroring) can match (or slightly exceed) its efficiency for small reads. In both cases, there is a single disk accessed. With 4 disks, RAID-1+0 can service four independent reads concurrently, while RAID-5 can service up to four independent reads concurrently, but perhaps as few as 1 if all reads are directed to the same spindle. Under heavy loads, all spindles will generally be busy, so performance is similar. Let me see if I understand. If I have a RAID10 with 4 or more disk, then for a mailstore this would be the optimal solution. I expect to have 6 or more disk in mirrors, so would that increase it's efficiency? keith ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] jbod questions
On Sep 29, 2006, at 2:41 AM, Roch wrote: IMO, RAIDZn should perform admirably on the write loads. The random reads aspects is more limited. The simple rule of thumb is to consider that a RAIDZ group will deliver random read IOPS with the performance characteristic of single device. That rule does not apply to either read or write streaming data but only for small random reads pattern. If that means you need to construct small RAIDZ groups then do consider mirroring as an alternative. So, mirroring, on jbods would give me the same/better performance than raidzn? Would that apply to fc drives or also to SATA? keith ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
[zfs-discuss] please remove my ignorance of raiding and mirroring
Folks, I've heard that for small reads/writes (like a mailstore), mirroring is preferred to raiding. Can some explain why or direct me to that info? I assumed that raidzn would be the preferred method but apparently not. thanks, keith ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
[zfs-discuss] jbod questions
Folks, We are in the process of purchasing new san/s that our mail server runs on (JES3). We have moved our mailstores to zfs and continue to have checksum errors -- they are corrected but this improves on the ufs inode errors that require system shutdown and fsck. So, I am recommending that we buy small jbods, do raidz2 and let zfs handle the raiding of these boxes. As we need more storage, we can add boxes and place them in a pool. This would allow more controllers and move spindles which I would think would add reliability and performance. I am thinking SATA II drives. Any recommendations and/or advice is welcome. thanks, keith ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
