Editing DiskMirroring

Using a software mirroring system on Solaris can be brutal. It is prone to configuration error and recovery can be a bitch. My personal point of view is buy as much central storage as you can afford and use a hardware raid, so you don't have to use to disksuite.. Since you are still reading, I guess you haven't splurged on the $50k raid NAS (Network Attached Storage). Let move on. * DisksuiteLayout - Planning your installation. * MirrorRaid1 - Good old mirrors. * MirrorRaid5 - Gobs of disks cobbled together. * DiskRecovery - Recovering your lost disksuite disks. ==2006-08: Disk Mirroring == === Mirror The Drives === Use the 256M slice 7 of the drive for the metadata partition. Naming convention * d10: the metadisk slice name * d11: the first copy of the d1 slice * d12: the second copy of the d1 slice Copy partition from one drive to another. The easiest way: * run format, pick source disk. * name the partition layout * in format, pick dest. disk. partition, "select" and pick the partition name, run "label" * we don't need to do "newfs" Set up meta database * metadb no args, "nothing defined * metadb -f -a -c 3 c1t0d0s7 c1t1d0s7 (source and dest disks) three dbs per slice. * metainit -f d11 1 1 c1t0d0s0 <-- one of the partitions you want to mirror * 1 1 use one slice for it * -f force if the disk is in use * "d11" = slice 1, mirror 1 * metainit -f d12 1 1 c1t1d0s0 Repeat for each slice that we're going to use. Map the new drive to the metadrive name * metainit d10 -m d11 <-- set up onesided mirror; repeat for each slice. * metastat will show us current setup Now, tell vfstab to boot off off the metadevice * metaroot d10 - metaddrive name for / (it edits /etc/system and /etc/vfstab) * edit /etc/vfstab manually, set /var to e.g. /dev/md/dsk/d30 * Reboot * in /etc/vfstab, make swap the mirror, d20 * Now, sync up the mirrors; d10 was already attached to d11, now attach d12 ** metattach d10 d12 ** for a 70G drive, it'll take about 3 hours to complete the mirroring. This should be done during a quiet time. ===Boot from either mirror=== In the ROM monitor: ok> * show-disks to get the logical names for the disks * do nvalias to give the boot disks names, e.g. root-disk & root-mirror * devalias will show the existing aliases * now test that we can boot using the two aliases * when Solaris is up, test it with metastat * ok> setenv boot-device root-disk root-mirror * on systems with a diag-device in ROM, must set that too * do a reset-all to simulate power cycle * set auto-boot true * set local-mac-address to FALSE - all interfaces have the same MAC address ===Replace A Drive=== *Probably* all you need to do is metareplace -e d10 c0t0d0s0 ... which will replace the device and enable it. Here's the much longer way: To replace a disk: * metadetach d10 d11 # (remove d11 from the d10 mirror. Do this for all slices on the failed disk) * metaclear d11 # (Do this for all slices on the failed disk) * metadb -d /dev/dsk/c0t0d0s1 # (clear the meta databases off of the failed disk) * replace physical disk. * Do whatever you need to do to AddAndRemoveDisk * prtvtoc /dev/rdsk/c0t1d0s2 | fmthard -s - /dev/rdsk/c0t0d0s2 # (copy the good disk's partition table to the new replacement disk) * metadb -a -c 3 c0t0d0s2 # (Recreate databases) * metainit d11 1 1 c0t0d0s0 # (Recreate submirrors. Do this for all slices on the disk) * metattach d10 d11 # (Reattach the new drive sub mirror to the mirror -- rebuilding starts!)

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This change is a minor edit.

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