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0 pointsjauntywundrkind1y ago0 comments

It's funny because Facebook uses btrfs for their systems & doesn't have these issues.

ZFS lovers need to stop this CoW against CoW violence.

0 comments

Someone correct me if I'm wrong but to my understanding FB uses Btrfs in either RAID 0, 1, or 10 only and not any of the parity options.

RAID56 under Btrfs has some caveats but I'm not aware of any annecdata (or perhaps I'm just not searching hard enough) within the past few weeks or months about data loss when those caveats are taken under consideration.

tuetuopay1y ago

> RAID56 under Btrfs has some caveats but I'm not aware of any annecdata (or perhaps I'm just not searching hard enough) within the past few weeks or months about data loss when those caveats are taken under consideration.

Yeah this is something that makes me consider trying raid56 on it. Though I don't have enough drives to dump my current data while re-making the array :D (perhaps this can be changed on the fly?)

SirGiggles1y ago

What's your starting array look like? If you're already on Btrfs then I recall you could do something like `btrfs balance -d raid6 -m raid1c3 /`

https://btrfs.readthedocs.io/en/latest/Balance.html

tuetuopay1y ago

Yeah I'm on btrfs raid 1 currently, with 1x1TB + 2x3TB + 2x4TB drives. Gotta love btrfs's flexibility regarding drive size :D

I'll have a look, thanks! I guess failing this will make me test by backup strategy that I have never tested in the past.

2 more replies

riku_iki1y ago

> It's funny because Facebook uses btrfs for their systems & doesn't have these issues.

they likely have distributed layer on top which takes care of data corruption and losses happening on specific server

j / k navigate · click thread line to collapse

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SirGiggles1y ago

Someone correct me if I'm wrong but to my understanding FB uses Btrfs in either RAID 0, 1, or 10 only and not any of the parity options.

tuetuopay1y ago

Yeah this is something that makes me consider trying raid56 on it. Though I don't have enough drives to dump my current data while re-making the array :D (perhaps this can be changed on the fly?)

SirGiggles1y ago

What's your starting array look like? If you're already on Btrfs then I recall you could do something like `btrfs balance -d raid6 -m raid1c3 /`

https://btrfs.readthedocs.io/en/latest/Balance.html

tuetuopay1y ago

Yeah I'm on btrfs raid 1 currently, with 1x1TB + 2x3TB + 2x4TB drives. Gotta love btrfs's flexibility regarding drive size :D

I'll have a look, thanks! I guess failing this will make me test by backup strategy that I have never tested in the past.

2 more replies

riku_iki1y ago

> It's funny because Facebook uses btrfs for their systems & doesn't have these issues.

they likely have distributed layer on top which takes care of data corruption and losses happening on specific server

j / k navigate · click thread line to collapse