HDD upgrade after 10GBE Install. Opinions

[hardlivinlow]

Sooo I just completed my 10G network upgrade and now its time to beef up the drive performance in the NAS box.

After the network upgrade I can pull about 235MB/s from a SMB share to a VM.

Current hardware
Dell R710
Perc H310
6X - 1TB WD Black 3.5 SATA-2 drives. RaidZ2
32GB Ram
Dual 10GBE Nic.

Uses for this FreeNas box

iSCSI Datastores to VM hosts

• SQL Database Server for Exchange, and Observium
• Dual AD/DNS Servers
• Few Ubuntu VMs hosting game servers

SMB shares for backups from clients
2 or so simultaneous Plex streams


Option 1

4 X WD PRO 4TB Reds with dual HGST 100GB SLOG SSD's on the Perc H310

SLOG
HGST 100GB SAS SSD 2.5'' HDD HUSSL4010BSS600 0B27395 - $50.00 Each

Spinners
WD Red Pro 4TB NAS Hard Disk Drive - 7200 RPM Class SATA 6Gb/s 128MB Cache 3.5 Inch - WD4002FFWX - $180.00 Each

Total $820.00


Option 2

Upgrade to a LSI SAS 9300-8i SAS3 12Gb/s card - $150.00

Run 4 spinners with no SLOG
Seagate Enterprise Capacity 3.5'' HDD 4TB 7200 RPM 4Kn SAS 12Gb/s 128MB Cache Internal Hard Drive ST4000NM0095 - $200.00 Each

Total $950.00



I'm not a pro with SLOG and disk setups on FreeNAS so there's that..

As far as performance what would be a better choice? will the SLOG setup preform good compared to option 2?

Future proof would of course be with the SAS 3 setup.

What do yall think?

 

[m0nkey_]

I would go with option 1. Mostly because it's overall cheaper and it's WD RED drives. I don't have a high opinion of Seagate drives.

Also note, iSCSI does asynchronous writes and you will probably not get much of a performance bump by using a SLOG. You can however force synchronous writes with zfs set sync=always.

 

[hardlivinlow]

I agree. I'm not much on seagate drives either. I only have six drive bays. Would it be better to split the drives up and say use a mirrored pair for asynch and the others synchronous with the cache drive? Seems I need to do some research on synchronous and asynchronous.

 

[Spearfoot]

Sooo I just completed my 10G network upgrade and now its time to beef up the drive performance in the NAS box.

After the network upgrade I can pull about 235MB/s from a SMB share to a VM.

Current hardware
Dell R710
Perc H310
6X - 1TB WD Black 3.5 SATA-2 drives. RaidZ2
32GB Ram
Dual 10GBE Nic.

Uses for this FreeNas box

iSCSI Datastores to VM hosts

• SQL Database Server for Exchange, and Observium
• Dual AD/DNS Servers
• Few Ubuntu VMs hosting game servers

SMB shares for backups from clients
2 or so simultaneous Plex streams


Option 1

4 X WD PRO 4TB Reds with dual HGST 100GB SLOG SSD's on the Perc H310

SLOG
HGST 100GB SAS SSD 2.5'' HDD HUSSL4010BSS600 0B27395 - $50.00 Each

Spinners
WD Red Pro 4TB NAS Hard Disk Drive - 7200 RPM Class SATA 6Gb/s 128MB Cache 3.5 Inch - WD4002FFWX - $180.00 Each

Total $820.00


Option 2

Upgrade to a LSI SAS 9300-8i SAS3 12Gb/s card - $150.00

Run 4 spinners with no SLOG
Seagate Enterprise Capacity 3.5'' HDD 4TB 7200 RPM 4Kn SAS 12Gb/s 128MB Cache Internal Hard Drive ST4000NM0095 - $200.00 Each

Total $950.00



I'm not a pro with SLOG and disk setups on FreeNAS so there's that..

As far as performance what would be a better choice? will the SLOG setup preform good compared to option 2?

Future proof would of course be with the SAS 3 setup.

What do yall think?

If you're serving up block storage w/iSCSI, a good first step would be to add more RAM. The docs state:

"For iSCSI, install at least 16 GB of RAM if performance is not critical, or at least 32 GB of RAM if good performance is a requirement."

So your current 32GB is the minimum amount of RAM the FreeNAS developers consider sufficient to provide robust iSCSI performance.

If you're really wanting to boost iSCSI performance, you should change to a mirror-based topology. IOPS scale by vdev, so 4 drives configured as a pair of mirrors will provide twice the IOPS of a 4-drive RAIDZ2 array. The more mirrors, the better. 6 drives set up has 3 mirrors will have 3 times the IOPS of a 6-drive RAIDZ2 array. And so on...

I'm not familiar with the HGST SSDs, but the model you listed seems to have the characteristics needed in a SLOG device, and servethehome.com lists HGST in their Top Picks for FreeNAS ZIL/SLOG Drives guide. So that's encouraging.

The thing about using a SLOG is not so much that it improves performance, but that it provides safety in the event of an unexpected power failure. It does improve performance when you follow 'best practices' and enable synchronous writes on the zvol you're serving out via iSCSI. Without a SLOG device, synchronous writes slow things down to a crawl. You can make iSCSI fly by disabling synchronous writes, but then you're skating on the edge... not a big deal if you're just running a lab, or unimportant, throw-away virtual machines. So it really depends on your use-case; you may not need a SLOG device at all.

Regarding hard drives... I like the Deskstar NAS line. The last two 4TB Deskstar drives I bought - newer models with 128MB of cache - have noticeably better performance than my older 4TB Deskstars, which only have 64MB of cache. These drives can be had for ~$135 at newegg.com.

Hope this helps... good luck!