Can ZFS mirror install boot with 1 failed drive?

[ender526]

Hello,

I am considering re-installing using a zfs mirror for redundancy more than data integrity. If I lose my FW to a bad drive I lose internal dns and internet. So my goal would be if I lost a drive, that both drives would be bootable and I could stay up on a single drive until Amazon prime delivered another drive. My question is, are both drives bootable when using the installer mirror option by default, Or do I need to mess with the partition tables?

Thanks!

[_Alchemist_]

My question is, are both drives bootable when using the installer mirror option by default, Or do I need to mess with the partition tables?

Hello ender526,

I just installed OPNsense 22.1.2 on a spare PC (Biostar J3160NH) with two Seagate 2TB SATA HDDs (zfs mirror) and tried booting with both, only the first and only the second HDD.

This were my results:

• Both HDDs: Boots just fine, as expected
• Only the first HDD (ada0): Boots just fine
• Only the second HDD (ada1): Boots just fine, but the CLI is broken (the screen hangs at the Kernel loading messages)

The Web GUI could be reached in all three cases.

Some more System information (the system time can be ignored):

Both HDDs

Code: [Select]

root@OPNsense:~ # zpool status
  pool: zroot
 state: ONLINE
  scan: resilvered 4.80M in 00:00:01 with 0 errors on Wed Jul 29 00:52:21 2015
config:

NAME          STATE     READ WRITE CKSUM
zroot         ONLINE       0     0     0
  mirror-0    ONLINE       0     0     0
    ada0p4    ONLINE       0     0     0
    gpt/zfs1  ONLINE       0     0     0

errors: No known data errors
root@OPNsense:~ # camcontrol devlist
<SEAGATE ST2000NM0033 NS01>        at scbus0 target 0 lun 0 (pass0,ada0)
<SEAGATE ST2000NM0033 NS01>        at scbus1 target 0 lun 0 (pass1,ada1)
root@OPNsense:~ # opnsense-version
OPNsense 22.1.2_2 (amd64/OpenSSL)

First HDD only

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root@OPNsense:~ # zpool status
  pool: zroot
 state: DEGRADED
status: One or more devices could not be opened.  Sufficient replicas exist for
the pool to continue functioning in a degraded state.
action: Attach the missing device and online it using 'zpool online'.
   see: https://openzfs.github.io/openzfs-docs/msg/ZFS-8000-2Q
  scan: resilvered 5.70M in 00:00:01 with 0 errors on Wed Jul 29 00:43:16 2015
config:

NAME          STATE     READ WRITE CKSUM
zroot         DEGRADED     0     0     0
  mirror-0    DEGRADED     0     0     0
    ada0p4    ONLINE       0     0     0
    gpt/zfs1  UNAVAIL      0     0     0  cannot open

errors: No known data errors
root@OPNsense:~ # camcontrol devlist
<SEAGATE ST2000NM0033 NS01>        at scbus0 target 0 lun 0 (pass0,ada0)
root@OPNsense:~ # opnsense-version
OPNsense 22.1.2_2 (amd64/OpenSSL)

Second HDD only

Code: [Select]

root@OPNsense:~ # zpool status
  pool: zroot
 state: DEGRADED
status: One or more devices could not be opened.  Sufficient replicas exist for
the pool to continue functioning in a degraded state.
action: Attach the missing device and online it using 'zpool online'.
   see: https://openzfs.github.io/openzfs-docs/msg/ZFS-8000-2Q
  scan: resilvered 4.80M in 00:00:01 with 0 errors on Wed Jul 29 00:52:21 2015
config:

NAME          STATE     READ WRITE CKSUM
zroot         DEGRADED     0     0     0
  mirror-0    DEGRADED     0     0     0
    ada0p4    UNAVAIL      0     0     0  cannot open
    gpt/zfs1  ONLINE       0     0     0

errors: No known data errors
root@OPNsense:~ # camcontrol devlist
<SEAGATE ST2000NM0033 NS01>        at scbus1 target 0 lun 0 (pass0,ada0)
root@OPNsense:~ # opnsense-version
OPNsense 22.1.2_2 (amd64/OpenSSL)

I hope this answered your question.