Best cheap profi SSD for ZIL
Hi to all,
Do you know OWC Mercury Pro 6G SSDs ? Only one supplier that shows their enterprise SSDs prices publicly
. They sell it through their own web shop (maybe exclusively).
I'm using OWC Mercury Pro 6G 50GB as ZIL. Can get one for $400. It's fantastic.
It has over 60MB/s with sequential 4KB/s write (qd=1). But with endurance 730 TB. It has OP (over-provisioning) set to 28%. Of course, you can use 'hdparm -N' and set it higher to get longer endurance. It has capacitors, 7 years warranty.
So, for ZIL it is really dream (relatively cheap).
It's there
http://eshop.macsales.com/shop/SSD/OWC/Mercury_6G/Enterprise
Reviews are there:
http://thessdreview.com/our-reviews...and-lsi-combine-for-a-great-enterprise-entry/
http://www.storagereview.com/owc_mercury_enterprise_pro_6g_ssd_review
Another good drive (the same price tag as OWC Mercury Pro) is Intel 710. It has capacitors too, but is slower then Mercury and has cca 1/3 endurance of Mercury (it is 100GB with 500 TB endurance, Mercury has 50GB with 730 TB).
By my mean, it's the best possibility, if you can't use DDRDRIVE or ZeusRAM, e.g. RAM based SSD. With OP, it can lasts for years. Mine is set to 20GB (the second Mercury drive I have is under testing of capabilities, so maybe I can raise OP to 10GB drive and get more endurance).
You can't use stripping ZIL for higher speed, because of qd=1, but for longer endurance it's possible. And it is often used in this manner.
In tests you must use
dd(1) with
conv=sync flag, to be as ZIL write. Look at source code of ZFS, it's free (best documentation
).
Our use of ZFS in production just now is primarily for PostgreSQL Plus databases, e.g. cashing zpools for it. I can't test any NFS numbers now. But PostgreSQL shines at ZFS !
But just now I'm in building of new filer for our ESXi and RHEV (RedHat KVM hypervisor) machines. We plan to use VDI next year, so we test cheap technology (relative to ... Oracle ... gold is cheaper
).
It's dual Xeon E5-2600 class machine, 256GB (RAM is cheap and we plan using deduplication hardly). Mainboard and case from SuperMicro. Processors are E5-2650, 8 cores (maybe overkill, but dedup, compress, ... and we have the same model in VM hosts too - so we want one type).
Bunch of LSI92xx SAS2 HBAs, dualport 10GE (board alone has Intel quad 1Ge).
Only boot, system, swap drives internally (SSD).
All of other drives I want in external (SuperMicro) JBOD cases (for case of service, replacement of server and so). Many of SSDs, Mercury Pro 6G 100-400GB - it's best and relatively cheap.
Why JBOD ? Because I'm hating RAIDs. Hehe, not really, but classic hw RAIDs, especially RAID5,6 are completely dead. ZFS is there. Because we plan to buy SATA drives for budget, there can be SATA/SAS expanders too (so I can use more JBOD cases in future; without be out of # of SAS2/SATA HBAs).
As SAN we are using SAS2 switches - nice little known thing - "from DAS (direct attached storage) to SAN". It's better, much cheaper, much speeder then 8G FC or 10GE or FCoe. From LSI, switch LSISAS 6160. Dual (HA config) multipath 24Gbit/s connect. Super. Cheap. Flexible. Simple. No additional protocol levels/stack on road (no encapsulation/translation: SCSI commands/FC/eth/switch/eth/FC/SCSI commands - simple SAS/switch/SAS - commands flown on wires
). Try it.
Cons is only 2m range (10m cables exists, but must be active and are more expensive).
So, I haven't own modern experiences with practical daily use of NAS based on ZFS (and NFS, iSCSI, CIFS) in enterprise. Our ESXi's are filled through SAS2 directly. So one of my predicted tests will be using SAS2 HBA as target - e.g. I want to make my own ZFS based SAS2 storage (e.g. SAS2 "RAID storage box"). And test ZFS speeds.
As an operating system, maybe Linux (preferably RHEL), Solaris|OpenSolaris|OpenIndiana|..., FreeBSD - which one win competition in speed and reliability.
I want to test FCoE, iSCSI, NFS, CIFS, too - to make benchmarks of all of this. Compared to SAS2 fabric/network.
So, next time I hope I can present same numbers - especially about NFS and iSCSI speeds.
Cheers