To check if a record exists, you can simply use the HEAD query.
“HEAD is almost identical to GET, but without the response body.” (https://www.w3schools.com/tags/ref_httpmethods.asp)
Unfortunately, there is no shortcut in CAP for a HEAD query, so simply use send with method HEAD.
sfsfSrv = await cds.connect.to('sfsf')
try {
await sfsfSrv.send('HEAD', `/User('${userId}')`)
return true // status 200
} catch (err) {
return false // status 404
}
I recently added some disks to my TrueNAS server and created a new encrypted pool named data2 on it. My old pool data was created years ago, before the zfs encryption feature was released, so it is an unencrypted pool. Now I wanted to move a dataset, i.e. photos, to my new pool data2. I tried to archieve this via TrueNAS Gui using the Replication Task, but always got errors that it’s not possible to send unencrypted data to an encrypted pool.
On Reddit I found a thread with a solution using the parameter -x encryption.
Because I prefer keeping all my snapshots when moving a dataset, I send my oldest snapshot first.
zfs send -v data/photos@manual-01-05-2019 | zfs recv -x encryption data2/photos
In the next step I created a new snapshot and did an incremental send with the parameter -I (send incremental snapshots).
zfs send -v -I data/photos@manual-01-05-2019 data/photos@manual-01-10-2020 | zfs recv -F -x encryption data2/photos
Compare the datasets with zfs diff (see example here) or use the classic diff command to compare the folders:
diff -qr /mnt/data/photos /mnt/data2/photos
#or in background
diff -qr /mnt/data/photos /mnt/data2/photos >> diff.output & disown
#check if process finished with "ps"
less diff.output
Check if all Snapshots were replicated with:
zfs list -t snapshot | grep data2/photos
After that I just changed the path for my NFS photo share and did a sudo mount -a on the clients. Now the whole dataset is moved and encrypted.