[opensuse-support] BTRFS raid 1
Hello, I now have two ssd of around 450Gb each on my PC. I have a root (/) of 100Gb - it's /dev/sda2 I would like to secure this root with an other 100Gb partition in /dev/sdb2 I'm unsure of the best way to do so :-( * make a btrfs raid 1. ** is it possible to make a btrfs add from a running root, or do I need to boot on some recovery system? ** once done will it be possible to boot (from uefi) to any partition (sda2 or sdb2)? in case sda2 fails, do the system boot? from here: https://btrfs.wiki.kernel.org/index.php/Incremental_Backup#Doing_it_by_hand.... I don't understand how to recover the backup in case of failure of the main system :-( thanks jdd -- http://dodin.org -- To unsubscribe, e-mail: opensuse-support+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-support+owner@opensuse.org
Le 23/02/2019 à 17:21, jdd@dodin.org a écrit :
* make a btrfs raid 1. ** is it possible to make a btrfs add from a running root, or do I need to boot on some recovery system?
well I don't know why my first attempts failed, the next one succeed # btrfs device add -f /dev/sdb2 / # btrfs balance start -dconvert=raid1 -mconvert=raid1 / and # btrfs fi df / Data, RAID1: total=23.00GiB, used=18.35GiB System, RAID1: total=32.00MiB, used=16.00KiB Metadata, RAID1: total=2.00GiB, used=912.86MiB GlobalReserve, single: total=58.55MiB, used=0.00B
** once done will it be possible to boot (from uefi) to any partition (sda2 or sdb2)? in case sda2 fails, do the system boot?
not tested yet, from the net, it seems it will start on degraded mode allowing removal of the defective disk (or replacement) jdd -- http://dodin.org -- To unsubscribe, e-mail: opensuse-support+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-support+owner@opensuse.org
On Sat 23 Feb 2019 07:52:05 PM CST, jdd@dodin.org wrote:
Le 23/02/2019 à 17:21, jdd@dodin.org a écrit :
* make a btrfs raid 1. ** is it possible to make a btrfs add from a running root, or do I need to boot on some recovery system?
well I don't know why my first attempts failed, the next one succeed
# btrfs device add -f /dev/sdb2 / # btrfs balance start -dconvert=raid1 -mconvert=raid1 /
and
# btrfs fi df / Data, RAID1: total=23.00GiB, used=18.35GiB System, RAID1: total=32.00MiB, used=16.00KiB Metadata, RAID1: total=2.00GiB, used=912.86MiB GlobalReserve, single: total=58.55MiB, used=0.00B
** once done will it be possible to boot (from uefi) to any partition (sda2 or sdb2)? in case sda2 fails, do the system boot?
not tested yet, from the net, it seems it will start on degraded mode allowing removal of the defective disk (or replacement)
jdd
Hi If your system allows for browsing to an efi file, then you should be able to pick up the efi file on the second disk to boot from, else you would need to look at adding manually with the efibootmgr command... -- Cheers Malcolm °¿° SUSE Knowledge Partner (Linux Counter #276890) SLES 15 | GNOME Shell 3.26.2 | 4.12.14-25.28-default Intel DQ77MK MB | i5-3470S X4 @ 3.60 GHz | Intel GPU [8086:0152] up 3 days 5:03, 2 users, load average: 0.19, -- To unsubscribe, e-mail: opensuse-support+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-support+owner@opensuse.org
On Sat, 23 Feb 2019 20:28:29 +0100
"Carlos E. R."
On 23/02/2019 17.21, jdd@dodin.org wrote:
* make a btrfs raid 1.
I recall reading that btrfs raid was broken. That it was recommended instead to create a normal raid, and in it create a normal btrfs filesystem.
Could you tell us where you read that? My backup to a btrfs raid system has been working without fail for the past two years. -- Bob
On 23/02/2019 20.50, Bob Williams wrote:
On Sat, 23 Feb 2019 20:28:29 +0100 "Carlos E. R."
wrote: On 23/02/2019 17.21, jdd@dodin.org wrote:
* make a btrfs raid 1.
I recall reading that btrfs raid was broken. That it was recommended instead to create a normal raid, and in it create a normal btrfs filesystem.
Could you tell us where you read that? My backup to a btrfs raid system has been working without fail for the past two years.
Here and elsewhere, but I did not make a note to just post a link, sorry. [...] Found it: https://wiki.archlinux.org/index.php/btrfs «Warning: The RAID 5 and RAID 6 modes of Btrfs are fatally flawed, and should not be used for "anything but testing with throw-away data." See the Btrfs page on RAID5 and RAID6 for status updates.» -- Cheers / Saludos, Carlos E. R. (from 15.0 x86_64 at Telcontar)
On Sat, 23 Feb 2019 21:27:12 +0100
"Carlos E. R."
On 23/02/2019 20.50, Bob Williams wrote:
On Sat, 23 Feb 2019 20:28:29 +0100 "Carlos E. R."
wrote: On 23/02/2019 17.21, jdd@dodin.org wrote:
* make a btrfs raid 1.
I recall reading that btrfs raid was broken. That it was recommended instead to create a normal raid, and in it create a normal btrfs filesystem.
Could you tell us where you read that? My backup to a btrfs raid system has been working without fail for the past two years.
Here and elsewhere, but I did not make a note to just post a link, sorry.
[...]
Found it:
https://wiki.archlinux.org/index.php/btrfs
«Warning: The RAID 5 and RAID 6 modes of Btrfs are fatally flawed, and should not be used for "anything but testing with throw-away data." See the Btrfs page on RAID5 and RAID6 for status updates.»
But this thread is about btrfs raid1. Which works very reliably for me here. -- Bob
participants (4)
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Bob Williams
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Carlos E. R.
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jdd@dodin.org
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Malcolm