RAID10 Setup

[anth]

Hi Guys,

Hoping you can help me out, I've tried googling and searching this forum but I can't find anything that's helping. Currently running 8.2.0-BETA3.

I have 8x 2TB drives and I want to create a RAID10 array. From my working out that should give me roughly 7.2TB.

I've tried:
- Creating a new volume with 2 disks mirrored
- Adding another two disks to the same volume mirrored
- Adding 4 disks to the same volume as striped

This gives me 10.7TB space, so it seems as though the 4 disk striped set is just being added on top, not actually striping the existing 4 disks?

Any help would be appriciated :)

Cheers

 

[anth]

Think I just worked it out. If I'm wrong please correct me but otherwise this might help other people too :)

When you add more disks to a pool you're actually creating a striped pool. All I had to do was add 2x 2TB drives in mirrored 4 times to the same pool and it seems to have striped the 4 sets of mirrors :)

 

[boomer50]

Anth.. How did you add the 2x2TB 4 times? Did you do this via the GUI or via the command line? Can you list your steps?

Thanks
Randy

 

[survive]

Hi boomer50,

Take a look at this: http://www.freenas.org/images/resou...s8.2_guide.html#__RefHeading__21161_266426721

Basically you just create another pool with the same name as the one you want to add the new vdev to.

Keep in mind you can add a single disk, a stripe, a mirror, a RAIDZ1, or a RAIDZ2 to any existing single disk, stripe, mirror, RAIDZ1, or RAIDZ2....zfs allows you to construct some ill-advised if not simply horrible pools out of whatever vdevs you can create. It's best to try to configure the new vdev as close as possible to how the existing vdev is set up (so you want the same number & "class" of drives in the same configuration as the original) so you don't wind up with unbalanced performance out of the resulting pool. Also remember that your data is not automatically "restriped" to include the new vdev when you add a vdev to a pool.

A favor if I may ask: if you are going to make a pool out of a bunch of mirrors could you maybe do an iozone benchmark run on the the pool after the initial creation and with each additional vdev? Use a command like "iozone -a -s 10g -r 4096" (adjust the "10g" part to be larger than your RAM size).

-Will

 

[anth]

Anth.. How did you add the 2x2TB 4 times? Did you do this via the GUI or via the command line? Can you list your steps?

Yup, just added 2x2TB as a mirror 4 times via the GUI.

 

[boomer50]

Survive,
I don't know how I missed it in the manual, but I did. I had read that section before and misunderstood it.. Anyway, I did get it to work. The results are listed below..

2 x Dual Core 5060 Xeon 3.0 GHz
12 GB RAM
4 x 500GB WD SATA II 7200 RPM (For VMware via iSCSI)
3 x 2 TB Seagate Baracuda SATA II 7200 RPM RaidZ1 (CIFS)
3Ware 9550SX-12MI RAID Controller (JBOD mode)

-----------------------------
Test 1 - ZFS with Two Disks Mirror

File size set to 16777216 KB
Record Size 4096 KB
Command line used: iozone -a -s 16g -r 4096
Output is in Kbytes/sec, Time Resolution = 0.000001 seconds, Processor cache size set to 1024 Kbytes, Processor cache line size set to 32 bytes, File stride size set to 17 * record size.

random random bkwd record stride
KB reclen write rewrite read reread read write read rewrite read fwrite frewrite fread freread
16777216 4096 40283 39633 105684 103415 44111 35663 110097 549341 140846 39309 39524 104405 98523

----------------
Test 2 - ZFS with Two Disks Mirror + another 2 Disks Mirrored (Volume Extended)

random random bkwd record stride
KB reclen write rewrite read reread read write read rewrite read fwrite frewrite fread freread
16777216 4096 79589 78890 245369 230192 82621 74658 180941 1511666 181406 77150 78737 229604 219861

A significant increase