Advice for ZFS - storage as backup-target (Veeam and Acronis), 10G

[Stril]

Hi!

I need a new backup-target for Veeam, Acronis Backup and some a fileserver with 3.5 Mio files.

The server should be able to serve nearly 10G read and write. Hardware is a 36-bay-supermicro-system with 2x Intel E5 2643 v2 and 128 GB RAM.

At the moment, I need about 70TB.

I have got a good offer for 10 TB SAS drives.


Now the question:
What would you recommend?

- Option 1: one big, mirrored volume:
32x 10 TB mirrored --> 140 TB --> 100TB usable
1x Intel Optane 900 as L2ARC
sync=disable

--> Should be fast, but resilver could be slow.


- Option 2:
2x 16x 10TB mirrored (2 zpools)

--> Faster resilver, but slower "day by day"

....or would you recommend something else? Is it important to use 2,4,8,16 drives or doesn't this matter?
Is 128 GB RAM enough, or should I extend?

Thank you for your advice!

Stril

 

[dswartz]

Having trouble understanding your proposed geometry. Is Option A raid10? If so, sounds reasonable. Not sure an L2ARC makes much sense, since it will be mostly writes.

 

[Stril]

Hi!

Yes, both options are using mirror (Raid 10). I am just unsure, if it is a good idea to use one "huge" pool instead of two smaller ones.

 

[gea]

Resilver time may be different but more import is to avoid a high fillrate of the pool as this increases fragmentation and reduce iops. A smaller pool with a high fillrate may be slower regarding resilver time than the larger pool with a lower fillrate. As a thumb rule for a good performance: avoid a fillrate > 80%, best is < 60%

Mostly an L2Arc is not helpful with 128GB RAM. With very many small files (3.5 Mio) it may be helpful. You can also enable read ahead on the L2Arc. Arcstat will show if you need the L2Arc..

Number of disks is only relevant for Raid-z and only if compress is not enabled. The number of datadisks as a power of 2 can then make sense for a higher usable capacity. Propably you want to enable lz4 compress. Then do not care about.