marianarlt wrote
jbkeh are you running a server? I didn't read most of this tbh, sorry, but it seems you still got issues.
Well, I am trying to run tvheadend, but that hardly counts.
No, I'm just a geriatric noob who has been using BTRFS as root for a few years, without problems on (multiple) single
dev/partitions, but would like to have the additional comfort of raid1 (two dev/partitions).
On a single dev/partition, BTRFS boots just fine and provides 'normal' functions just like ext3/4.
It's the 'extras' that I like:
1. Integrity checking/repair ("scrub").
2. Temporal backups ("snapshots").
3. Relatively quick 'physical' backups ("send/receive").
4. Easy modification to number of dev/partitions in the filesystem's 'pool'.
The first three run concurrently with normal operations (no downtime); the fourth may require a reboot.
"Scrub" takes less than 20 minutes (and almost rarely finds anything amiss (power failures).
"Snapshots" of the entire system takes about 3 seconds.
"Send/receive" backups take anywhere from 20 seconds to 20 minutes depending on the size of the changes since the
previous "send/reveive".
Comparing BTRFS to ZFS is like asking, "Which is more, an apple or an orange?" - the context is everything.
Although the two are generally addressing the same "ballpark", the underlying "mechanics" are quite different and thus
their approach is also different.
Oracle's BTRFS idea of raid1 is not the standard "n /dev/partitions, each a copy of the first" but rather "n /dev/partitions with
2 copies (including the original) spread over them", which allows for only a single drive failure, no matter how
many drives are in the 'pool', but gives better drive utilization. Oracle has said for many years they were going to 'address'
this, but instead they have 'doubled down' on their raid1 approach with the recent addition of raid1C3 and raid1C4. Like their
raid1 (which could be called raid1C2), one can have "n /dev/partitions, with C copies (including the original) spread over them".
This is my biggest complaint - Oracle tosses out these little 'gems' with almost no fanfare and implications.
Wonder when people notice that raid1C3/4 obviates RAIDZ5/6 (no parity, no journalling, NO WRITE-HOLE)?
(must get back to making a new initrd) ....