BTRFS and load shedding

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bar1

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Hi, I recently changed my server to Unraid with btrfs.
however i came across a few articles that claim that btrfs is a terrible idea without a UPS, and i can corrupt
my file system in the event of a power failure.

Should i be changing to xfs (or get a UPS),i assume it'll be a big job.
For some very very odd reason i still didn't get load shedding in 2020, but of course
we all know it's coming.
 
I had a few hard shutdowns on my unraid box and it got upset. Managed to get it going again but i bought a UPS.
Unraid has native APC support, just get the smallest one they have (with USB) and it will allow the box to have a graceful shutdown.
 
shutting down a computer by yanking the power cord out is like closing the door while your foot is still inside
its gonna hurt sometimes
 
A bit late to the party, only noticed this thread now.

While @DrJohnZoidberg is correct, it's better overall to have a UPS, the btrfs filesystem only has one specific issue.

If you have your data in raid5/6 mode (metadata should always be raid1), and a drive fails, AND you get an unexpected shutdown before it repairs the array, then you can lose data or the whole array. You'd need a very strong UPS in order to last an entire scrub / rebuild.

Some folks use btrfs on top of an mdadm RAID array though, which wouldn't be susceptible to this particular failure mode. I'm not sure what Unraid does by default.
 
newby_investor said:
A bit late to the party, only noticed this thread now.

While @DrJohnZoidberg is correct, it's better overall to have a UPS, the btrfs filesystem only has one specific issue.

If you have your data in raid5/6 mode (metadata should always be raid1), and a drive fails, AND you get an unexpected shutdown before it repairs the array, then you can lose data or the whole array. You'd need a very strong UPS in order to last an entire scrub / rebuild.

Some folks use btrfs on top of an mdadm RAID array though, which wouldn't be susceptible to this particular failure mode. I'm not sure what Unraid does by default.
Click to expand...
I currently don't have any raid, 2 hard drives in jbod config
 
newby_investor said:
In that case, BTRFS with raid1 is very stable. You can do raid0 if you like to live dangerously, but keep your metadata in raid1.
Click to expand...
Thanks will leave it as btrfs for now. Worst case will recover from backup
 
bar1 said:
Thanks will leave it as btrfs for now. Worst case will recover from backup
Click to expand...
If you have (known good) backups, then you can afford to play a bit fast and loose, experiment and learn a little. Restoring from backups is inconvenient but not a tragedy.
 
I have been running a server at home probably since 2010, never really felt the need for a UPS.
 
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