fsyncs / SECOND ZFS

[fusion]

Hello,

On a server with 2 512GB SSDs, RAID 1 (ZFS), I get a fsyncs / SECOND.

The discs are: Samsung PM871a

These values are normal?

We need to put another SSD for cache and log ,although the discs are ssd??

I can put the cache and the log on a single disc or dangerous and neceistaria best 2 discs for this?

because in my server I have only 3 disks 512 gb.

thanks

 

[LnxBil]

Yes, that's true. Those are cheap-as-hell SSD that are almost as bad as a hard disk for synchronous writes. Please, please buy enterprise SSD for ZOL if you want to have a fast ZFS.

Please refer to this post where good and a lot of bad drives are listed:

http://www.sebastien-han.fr/blog/20...-if-your-ssd-is-suitable-as-a-journal-device/


You really want to have ZIL on a mirrored enterprise grade SSD with very fast synchronous write rates. L2ARC is not necessary and in most cases will slow down your system if you already have SSD-backed storage.

 

[fireon]

Here with Enterprise SSD as cache (Samsung SSD SM863 240GB)

pveperf /v-machines/home 
CPU BOGOMIPS: 40002.08
REGEX/SECOND: 2672715
HD SIZE: 4921.38 GB (v-machines/home)
FSYNCS/SECOND: 5189.33