some ?tions reg. ZFS in N4F: migrating/expanding/performance

[p0ddie]

Hi there,

I have a HP MicroServer 40L running Nas4Free 9.1.0.1 x64 rev344 with 4x Samsung HD204UI drives. It has a AMD Turion(tm) II Neo Dual-Core Processor with 1,5GHz.

I have encrypted each drive with AES-256 and then formed a Raid-Z1 with ZFS.

While writing all my data back to my drives I get around 22MB/s. Is this normal speed or too slow? I had a Raid 5 with Blowfish encryption before and got around 35 MB/s. My CPU is not fully maxed out - an ideas if I can squeeze out some more write performance? Does N4F support some AES256 crypto accelerators I can throw into USB or a PCIe slot?


Furthermore, I have some general questions about the usage of ZFS (or ZFS in general) in NAS4Free.

I come from a world of hardware RAID controllers (3ware, Areca and such) and commercial NAS like Netgear ReadyNAS, Thecus and so on.

All of these support - in one way or the other, the following:

- Migrate from RAID5 to RAID6 (using a hot spare or an additional drive)
- RAID6 to RAID5 (if you need more space you can sacrifice one parity drive)
- Expand an existing RAIDs capacity by adding another drive to the pool

Stuff that would be very useful in Nas4Free, too. Now as I understand all of the above is not possible in Nas4Free, not with GEOM RAID, not with ZFS.

Is this a limitation of ZFS in general (who cares about GEOM) or just not implemented (yet) in Nas4Free?

How do I add another drive to my ZFS pool to have more capacity while retaining redundancy, is there some other way I don't understand?

Please don't take this as criticism, I just want to evaluate what the best options for me are. Thanks!

[raulfg3]

While writing all my data back to my drives I get around 22MB/s. Is this normal speed or too slow?

I think that is normal, please test read speed, can be 45 to 50 MB/s.

How do I add another drive to my ZFS pool to have more capacity while retaining redundancy,

Because you have 4 disk in raidZ1, to add more space , you need to add other vdev( 3 or 4 disk in raidz1) you don't lose redundancy & improve trhoughtput ( writes are x2 of your actual write speed).

One big advantage of ZFS is that you can detach your actual 4 disk, atach in a new box with more SATA ports and import it ( Zpool import) and your data are other time magically in-line ( I change one time motherboard, and two times the SATa controller and my pool survive and do not lose data).

Does N4F support some AES256 crypto accelerators

Yes , google about crypto accelerators that suport BSD, but for home user 22MB/s write is not so bad (test read, please)

Migrate from RAID5 to RAID6 (using a hot spare or an additional drive)

NO, in Nas4Free if you use RaidZ1 it's posible to add a "spare Disk" but no to convert to Raidz2 as far as I know.


Please read this post about how ZFS works ( it's not important that was write to FreeNAS 8 , ZFS works in the same way in all O.S.) http://forums.freenas.org/showthread.ph ... hlight=ppt

[p0ddie]

ok, what a shame I need to add only one more drive and don't want to buy new hardware /my N40L is 2 weeks old) but I'll settle for what I have. Thanks for your reply!