gmirror, gpart and MBR vs GPT in the Handbook

[Peter Giessel]

On 2013, Dec 2, at 21:38, Polytropon <freebsd at edvax.de> wrote:

> On Mon, 02 Dec 2013 17:23:20 -0900, Peter Giessel wrote:
>> UFS works on drives bigger than 3 TB (ref /dev/da1p1 and /dev/mirror/gm0.journal):
> 
> That's impressive! Did you apply any special tuning for newfs,
> or did you require something "non-standard" when creating the
> partitions? I'm just asking because sooner or later I will
> probably get disks > 2 TB and intend to use them with UFS. :-)

As I recall, with the gmirrored 3TB drives (/dev/mirror/gm0.journal), I pretty much followed this:
http://www.freebsd.org/doc/handbook/geom-gjournal.html

But of course, I substituted:
gjournal label /dev/mirror/gm0
and
newfs -O 2 -J /dev/mirror/gm0.journal

for:
gjournal label /dev/da4
and
newfs -O 2 -J /dev/da4.journal
respectively.

Also a big *THANK YOU* to Warren Block as I found the Handbook section 19.4.3. extremely useful in setting up gmirror.

There are no tweaks or special tuning.  Its an old repurposed Pentium 4 running:
# uname -a
FreeBSD media.REDACTED 9.2-STABLE FreeBSD 9.2-STABLE #0: Sun Nov 10 08:09:31 AKST 2013     root at media.REDACTED:/usr/obj/usr/src/sys/MEDIA  i386

The kernel is nothing special, just a GENERIC kernel with a bunch of stuff that I wasn’t using commented out to save resources.

/dev/daX is a 3ware raid5 divided into 2 volumes (so I could use traditional MBR, etc with the smaller volume):
#tw_cli /c0 show all
/c0 Driver Version = 3.80.06.003
/c0 Model = 9550SXU-4LP
/c0 Available Memory = 112MB
/c0 Firmware Version = FE9X 3.08.00.029
/c0 Bios Version = BE9X 3.10.00.003
/c0 Boot Loader Version = BL9X 3.02.00.001
/c0 Serial Number = L320912A9410199
/c0 PCB Version = Rev 032
/c0 PCHIP Version = 1.60
/c0 ACHIP Version = 1.90
/c0 Number of Ports = 4
/c0 Number of Drives = 4
/c0 Number of Units = 1
/c0 Total Optimal Units = 1
/c0 Not Optimal Units = 0 
/c0 JBOD Export Policy = off
/c0 Disk Spinup Policy = 1
/c0 Spinup Stagger Time Policy (sec) = 1
/c0 Auto-Carving Policy = off
/c0 Auto-Carving Size = 2048 GB
/c0 Auto-Rebuild Policy = on
/c0 Rebuild Rate = 1
/c0 Verify Rate = 1
/c0 Controller Bus Type = PCIX
/c0 Controller Bus Width = 64 bits
/c0 Controller Bus Speed = 66 Mhz

Unit  UnitType  Status         %RCmpl  %V/I/M  Stripe  Size(GB)  Cache  AVrfy
------------------------------------------------------------------------------
u0    RAID-5    OK             -       -       64K     4190.92   ON     OFF    

Port   Status           Unit   Size        Blocks        Serial
---------------------------------------------------------------
p0     OK               u0     1.82 TB     3907029168    Z1F3MCT3           <- replacement drive 
p1     OK               u0     1.82 TB     3907029168    S1F0CN97           <- replacement drive 
p2     OK               u0     1.82 TB     3907029168    W1E430FV           <- replacement drive
p3     OK               u0     1.36 TB     2930277168    9VS2X5P6           <- original drive

3 of the 4 drives have died in the 5 years since I set this up (hence the size disparity)...

#tw_cli /c0/u0 show all
/c0/u0 status = OK
/c0/u0 is not rebuilding, its current state is OK
/c0/u0 is not verifying, its current state is OK
/c0/u0 is initialized.
/c0/u0 Write Cache = on
/c0/u0 volume(s) = 2
/c0/u0 name =                      
/c0/u0 serial number = 9VS2Y6AV80EE4B00AB32 
/c0/u0 Ignore ECC policy = off       
/c0/u0 Auto Verify Policy = off       
/c0/u0 Storsave Policy = protection  
/c0/u0 Command Queuing Policy = on        

Unit     UnitType  Status         %RCmpl  %V/I/M  Port  Stripe  Size(GB)
------------------------------------------------------------------------
u0       RAID-5    OK             -       -       -     64K     4190.92   
u0-0     DISK      OK             -       -       p3    -       1396.97   
u0-1     DISK      OK             -       -       p2    -       1396.97   
u0-2     DISK      OK             -       -       p1    -       1396.97   
u0-3     DISK      OK             -       -       p0    -       1396.97   
u0/v0    Volume    -              -       -       -     -       20        
u0/v1    Volume    -              -       -       -     -       4170.92