Replace HDD in UFS RAID 5 Volume

[Nik Ansell]

Hello All,

I am new to FreeNAS but loving it so far. It's really simple to get up and running and the plugins really make it worthwhile. The performance by far exceeds my previous iomega NAS too :)

My question is related to replacing a disk in a UFS RAID 5 volume.
I have a 4 disk volume named vol1 in a RAID 5 set using UFS, dmesg section below:

GEOM_STRIPE: Device vol1 created (id=3008995252).
GEOM_STRIPE: Disk ada3 attached to vol1.
GEOM_STRIPE: Disk ada2 attached to vol1.
GEOM_STRIPE: Disk ada1 attached to vol1.
GEOM_STRIPE: Disk ada0 attached to vol1.
GEOM_STRIPE: Device stripe/vol1 activated.
GEOM_RAID5: Module loaded, version 1.1.20130907.44 (rev 5c6d2a159411)

One of my drives (/dev/ada0) has a number of unreadable sectors which is gradually increasing and I would like to replace the disk.

My experience of RAID is many years old and always using hardware RAID in servers, such as Compaq/HP, Dell etc. In the past when a drive has failed, I have simply pulled the disk out, replaced it with another, then told the RAID controller/RAID software to rebuild the data on the new disk using the parity across the other disks in the set.

However.... I cannot figure out how to do this in FreeNAS. I have read the manual and searched all over the web and this forum and can only find examples of replacing a disk which has FAILED completely. I cannot see an option in the GUI to REPLACE, or Take OFFLINE anywhere as stated in the manual.

Would someone be kind enough to walk me through the steps I should take, to remove one disk, replace it with another and kick off the data rebuild. I am reasonably comfortable in a shell if needed.

Thank you in advance!

Kind Regards,
Nik

More relevant info from dmseg below...

FreeBSD 9.2-RELEASE-p12 #0 r262572+b043649: Sun Sep 28 23:03:31 PDT 2014
root@build3.ixsystems.com:/tank/home/jkh/build/921/freenas/os-base/amd64/fusion/jkh/921/freenas/FreeBSD/src/sys/FREENAS.amd64 amd64
gcc version 4.2.1 20070831 patched [FreeBSD]
CPU: Intel(R) Core(TM) i3-4130 CPU @ 3.40GHz (3400.07-MHz K8-class CPU)
Origin = "GenuineIntel" Id = 0x306c3 Family = 0x6 Model = 0x3c Stepping = 3
Features=0xbfebfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CLFLUSH,DTS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,PBE>
Features2=0x7fdafbbf<SSE3,PCLMULQDQ,DTES64,MON,DS_CPL,VMX,EST,TM2,SSSE3,<b11>,FMA,CX16,xTPR,PDCM,PCID,SSE4.1,SSE4.2,MOVBE,POPCNT,TSCDLT,AESNI,XSAVE,OSXSAVE,AVX,F16C,RDRAND>
AMD Features=0x2c100800<SYSCALL,NX,Page1GB,RDTSCP,LM>
AMD Features2=0x21<LAHF,ABM>
Standard Extended Features=0x27ab<GSFSBASE,TSCADJ,SMEP,ENHMOVSB,INVPCID>
TSC: P-state invariant, performance statistics
real memory = 8589934592 (8192 MB)
avail memory = 8100642816 (7725 MB)
Event timer "LAPIC" quality 600
ACPI APIC Table: <ALASKA A M I>
FreeBSD/SMP: Multiprocessor System Detected: 4 CPUs
FreeBSD/SMP: 1 package(s) x 2 core(s) x 2 SMT threads
cpu0 (BSP): APIC ID: 0
cpu1 (AP): APIC ID: 1
cpu2 (AP): APIC ID: 2
cpu3 (AP): APIC ID: 3

ada0 at ahcich0 bus 0 scbus0 target 0 lun 0
ada0: <Hitachi HDS5C3020ALA632 ML6OA5C0> ATA-8 SATA 3.x device
ada0: Serial Number ML2220F31WJ11H
ada0: 600.000MB/s transfers (SATA 3.x, UDMA6, PIO 8192bytes)
ada0: Command Queueing enabled
ada0: 1907729MB (3907029168 512 byte sectors: 16H 63S/T 16383C)
ada0: Previously was known as ad4
ada1 at ahcich1 bus 0 scbus1 target 0 lun 0
ada1: <Hitachi HDS5C3020ALA632 ML6OA5C0> ATA-8 SATA 3.x device
ada1: Serial Number ML2220F31YKJ2H
ada1: 600.000MB/s transfers (SATA 3.x, UDMA6, PIO 8192bytes)
ada1: Command Queueing enabled
ada1: 1907729MB (3907029168 512 byte sectors: 16H 63S/T 16383C)
ada1: Previously was known as ad6
ada2 at ahcich2 bus 0 scbus2 target 0 lun 0
ada2: <Hitachi HDS5C3020ALA632 ML6OA5C0> ATA-8 SATA 3.x device
ada2: Serial Number ML2220F31WR1LE
ada2: 600.000MB/s transfers (SATA 3.x, UDMA6, PIO 8192bytes)
ada2: Command Queueing enabled
ada2: 1907729MB (3907029168 512 byte sectors: 16H 63S/T 16383C)
ada2: Previously was known as ad8
ada3 at ahcich3 bus 0 scbus3 target 0 lun 0
ada3: <Hitachi HDS5C3020ALA632 ML6OA5C0> ATA-8 SATA 3.x device
ada3: Serial Number ML2220F31XKSSH
ada3: 600.000MB/s transfers (SATA 3.x, UDMA6, PIO 8192bytes)
ada3: Command Queueing enabled
ada3: 1907729MB (3907029168 512 byte sectors: 16H 63S/T 16383C)
ada3: Previously was known as ad10

 

[dlavigne]

I think you're SOL in repairing this volume as "UFS RAID5 is not supported as it is an unmaintained summer of code project which was never integrated into FreeBSD". Sounds like it is time to consider backing up the data and formatting a new, supported volume (which will only be ZFS beginning with 9.3).

 

[HoneyBadger]

Not sure how it goes under UFS now since I haven't touched it in a while, but trying selecting your volume in the GUI, clicking "Volume Status" at the bottom, then select your offending disk and choose "REPLACE" which should then turn into "DETACH."

You might also be able to do it from command prompt, but I'll admit I haven't used UFS since the FreeNAS version number started with a 0.

 

[cyberjock]

That is for ZFS, not UFS. I think dlavine has it right and that the UFS needs to be replaced with ZFS. FreeNAS 9.3 has no UFS support so you are about to be on an unsupported version and don't have a path to upgrade.

 

[Nik Ansell]

Thanks for the quick replies! I guess the support from the forum is as good as the product :)

I already back up my important stuff, I'm now in the process of executing several rsync jobs to backup all the other stuff.

I have my jails installed on the volume I need to blow away. Any tips on how to backup and restore the jails folder? Will rsync -arh -l -H copy everything over that I need?

 

[Nik Ansell]

Scrap my jail backup question, I've just found warden export :).. Perfect.

 

[Nik Ansell]

That is for ZFS, not UFS. I think dlavine has it right and that the UFS needs to be replaced with ZFS. FreeNAS 9.3 has no UFS support so you are about to be on an unsupported version and don't have a path to upgrade.

Nice guide cyberjock BTW. It answered a lot of my zfs questions and provided good advice for a FreeNAS noob like myself.

 

[cyberjock]

Glad you enjoyed it. :)