Video storing hardware

[Andres Gonzalez]

Hi,

I need to record video from 28 cameras that write about 7 Mbps (each).

I have the following hardware:

Mother: Supermicro MBD-X9DRD-7LN4F-JBOD-O
CPU: 2x INTEL XEON E5-2609V2
RAM: 96GB
HBA SAS: AOC-SAS2-9211-8I
HD: 18x WD4001FYYG
Read Cache: Intel S3500 SSD 240GB(SSDSC2BB240G4)
Write Cache: No yet defined, a "recommended" Intel SSD for ZIL.

This hardware can be good enough ?
Thanks.

 

[marbus90]

Write cache would only be used if you utilize NFS or iSCSI as storage backend or are forcing sync writes on the pool. But the pool should be fast enough to be able to accept this low datarate without problems, especially if you do 3x 6disk raidz2 vdevs.
Read cache SSD is not needed. at 96GB RAM you already have up to 72GB of read cache in RAM. Only thing the L2ARC SSD would be doing is dying fast - as I observed my L2ARC usage, it seems that everything written to the storage lands in ARC or L2ARC as well. That can kill a SSD quite fast.

The drives are a very good choice, the 7200rpm may or may not be neccessary - but they help if 28 streams are being written at the same time. I'd just drop in a spare or two for personal comfort. Mostly the drives aren't screeching to a halt but only give out occassional checksum errors - in this case most of the HDD is still good and can be used as parity still, if you resilver to a spare drive.

 

[Andres Gonzalez]

How can I see the ZIL or L2ARC use of a system ?
In this case, you mention that I can have up to 72 GB of read cache, how do you "know" this number ?

Thanks.

 

[Bidule0hm]

There's two scripts (arc_summary.py and arcstat.py) you can launch in the CLI ;)

 

[Andres Gonzalez]

Great ! Is something similar to ZIL ?

 

[Bidule0hm]

The question is unclear. But the scripts are for the ARC (and L2ARC), I don't remember if they give stats about ZIL and SLOG, just try and you'll see ;)

 

[marbus90]

ARC is usually set at 0.75x the total available system RAM. It won't be that size from the start because there would be nothing in ARC - but as you access the data, it would be loaded. Same as with L2ARC. But really, even on my VM storagebox I need over 10 days to fill 238GB of L2ARC and its rarely read from.

For SLOG usage you don't need a script. Just look up the specifications of your DVR system and tell me which storage protocol it uses.

Still, again, the HDDs are fast enough for that workload. SSD caching not needed. perfect constelllation.

 

[Andres Gonzalez]

The cameras writes directly against a Windows server that is going to have an iSCSI (FreeNAS) resource.

Regarding the scrips, cool info., is there anything similar to SLOG ?

 

[Darren Myers]

The cameras writes directly against a Windows server that is going to have an iSCSI (FreeNAS) resource.

Regarding the scrips, cool info., is there anything similar to SLOG ?

keep in mind that with iSCSI youll have 50% of the pool size to work with as per @cyberjock 's manual

 

[Andres Gonzalez]

Quick search and I couldn't find @cyberjock 's manual, why only 50% with iSCSI ?

 

[Bidule0hm]

Because the more you fill the pool the worse the perfs are. That's why we usually recommend to not fill more than 80 % (or 50 % in case of iSCSI) of the pool ;)

 

[Darren Myers]

Because the more you fill the pool the worse the perfs are. That's why we usually recommend to not fill more than 80 % (or 50 % in case of iSCSI) of the pool ;)

Bidule0hm seems to be a wizard...and beat me too it. I originally was gonna use FreeNAS for iSCSI...until i read the "dont fill pool over 50% due to fragmentation" and i cried....and accepted it, so now i use CFIS :P

 

[marbus90]

http://doc.freenas.org/9.3/zfsprimer.html < ZFS primer in the FreeNAS documentation. Scroll down all the way or ctrl+f for iscsi.

I don't recommend adding another layer of complication to that. Look if you can set it up with FreeBSD jails or hope that linux jails work for you.

 

[Darren Myers]

http://doc.freenas.org/9.3/zfsprimer.html < ZFS primer in the FreeNAS documentation. Scroll down all the way or ctrl+f for iscsi.

I don't recommend adding another layer of complication to that. Look if you can set it up with FreeBSD jails or hope that linux jails work for you.

Marbus90 saves the day, thats the article i couldnt find..i thought cyber had it in his manual, heres its a doc.... all well :) thanks!

 

[Andres Gonzalez]

http://doc.freenas.org/9.3/zfsprimer.html < ZFS primer in the FreeNAS documentation. Scroll down all the way or ctrl+f for iscsi.

I don't recommend adding another layer of complication to that. Look if you can set it up with FreeBSD jails or hope that linux jails work for you.

OK, so with CIFS or NFS 80% of the pool can be used ?
When adding another layer you meant the Windows server ? Is of, it's needed as the software that manages the cameras only run on Windows.

 

[marbus90]

you shouldn't fill the pool over 90% because you'll see performance impacts. could be that it's still fast enough though.

If it works via mounting a CIFS share as drive letter, that's preferable then. Do not buy a SLOG device for CIFS. It does not help.

 

[Andres Gonzalez]

It's not the case, but is there anyway to improve CIFS shares with a SLOG device ?

 

[depasseg]

It's not the case, but is there anyway to improve CIFS shares with a SLOG device ?

nope. SLOG improves ZIL performance, ZIL is only used for Sync Writes, and CIFS doesn't use Sync Writes.