From time to time one may wish to move a CWFS instance from one device to another. Perhaps the old device is full or faulty. Perhaps you’d just like to make a backup. In any case, the process is fairly simple.
Prepare new device
After installing the new drive and powering up the machine, the first
thing to do is identify the new device. The
indicates that the new device has been recognised.
cpu% ls '#S' '#S/sdD0' '#S/sdD1' '#S/sdctl' cpu% cat '#S/sdD0/ctl' inquiry KINGSTON SA400S37240G config 0040 capabilities 2F00 dma 00550020 dmactl 00550020 rwm 1 rwmctl 0 lba48always off model KINGSTON SA400S37240G serial 50026B768422720C firm SBFKJ4.3 feat lba llba smart power nop ata8 geometry 468862128 512 alignment 512 0 missirq 0 sloop 0 irq 18977 30 bsy 0 0 nildrive 6 part data 0 468862128 cpu%
Next, we prepare the MBR and DOS partition table with
cpu% disk/mbr -m /386/mbr '#S/sdD0/data' cpu% disk/fdisk -w -a '#S/sdD0/data' cpu% cat '#S/sdD0/ctl' inquiry KINGSTON SA400S37240G config 0040 capabilities 2F00 dma 00550020 dmactl 00550020 rwm 1 rwmctl 0 lba48always off model KINGSTON SA400S37240G serial 50026B768422720C firm SBFKJ4.3 feat lba llba smart power nop ata8 geometry 468862128 512 alignment 512 0 missirq 0 sloop 0 irq 20034 55 bsy 0 0 nildrive 6 part data 0 468862128 part plan9 63 468862128 cpu%
Now we can set up the plan9 partition table. I’ve chosen to elide the ‘other’ partition this time around as I’ve never used it in the entire 6 years that I’ve been using the previous filesystem.
cpu% disk/prep -w -a 9fat -a nvram -a fscache -a fsworm '#S/sdD0/plan9' no plan9 partition table found 9fat 204800 nvram 1 fscache 78109544 fsworm 390547720 cpu%
Copy old WORM
Disable the background dump service and trigger a final dump of the old file system:
cpu% echo cwcmd startdump 0 >>/srv/cwfs.cmd cpu% echo dump >>/srv/cwfs.cmd
There’s no point copying the entire WORM partition so let’s work out
how much of it needs to be copied using the
cpu% con -C /srv/cwfs.cmd statw cwstats main filesys main maddr = 3 msize = 5147 caddr = 518 csize = 694845 sbaddr = 1668338 craddr = 1697494 1697494 roaddr = 1697497 1697497 fsize = 1697599 1697599 0+48% slast = 1668081 snext = 1697498 wmax = 1697497 0+48% wsize = 3484185 1+ 0% 223247 none 8903 dirty 0 dump 461561 read 1134 write 0 dump1 cache 5% full
So we need only copy
fsize 16K blocks. We can use
dd(1) to do so, but please, double and triple check the
order of your arguments before running this command!
cpu% dd -if '#S/sdD1/fsworm' -of '#S/sdD0/fsworm' -bs 16k -count 1697599 cpu%
This will likely take quite some time. In the example above, copying 1697599*16K ≈ 25G took around 10 minutes or so.
Bring up new FS
cpu% bind -a '#S' /dev cpu% cwfs64x -n newcwfs -f /dev/sdD0/fscache -C -c config: service cwfs config: config /dev/sdD0/fscache config: filsys main c(/dev/sdD0/fscache)(/dev/sdD0/fsworm) config: filsys dump o config: recover main config: end checktag pc=20eb0f n(3) tag/path=Tnone/0; expected Tsuper/2 current fs is "main" 11 uids read, 7 groups used 63-bit cwfs as of Mon Nov 9 20:51:45 2020 last boot Sat Nov 28 14:34:23 2020 cpu%
You can now mount the new filesystem:
cpu% mount /srv/newcwfs /n/newroot cpu% mount /srv/newcwfs /n/newdump dump cpu%
Copy 9fat and nvram
The last thing to do is to copy the 9fat and nvram partitions from your old disk to the new one. This is trivial:
cpu% cp '#S/sdD1/9fat' '#S/sdD1/nvram' '#S/sdD0' cpu%
You should now be able reboot from the new disk.