Hi,
I built the following system:
- Motherboard: Supermicro X9SCM-f-o
- CPU: Intel Xeon 1220Lv2
- RAM: 2x8Go Kingston ECC KVR16E11/8I
- 6x1TB HDD (in RAIDZ2)
- FreeNAS version 9.2.0
- No encryption
- No compression
- Using CIFS
The system is running fine and before I use it for real (i.e. in production, but only for home usage), I'm experimenting with it to get use to FreeNAS (and trying to read the manual).
From a performance point of view, I'm very happy.
Internally I get about 300MB/s for writes and 400MB/s for reads (I used joeschmuck's tests in his post "Intel NIC vs RealTek NIC - Performance Testing", thanks).
And over the network (gigabit LAN) I get 90-100MB/s on large files (in my case I would have been happy with 60MB/s already!). And with small files I get between 40MB/s (2MB average file size) to 15MB/s (370kB average file size).
The power consumption is also quite good: about 60W when working, 50W idle (HDD not sleeping) and 20-25W for the mainboard and CPU.
As said, I used it first to experiment and get used to FreeNAS.
So I started to think about some tests to perform to see how FreeNAS would react and have an idea about its robustness.
On this forum I read some stories about how it seems easy to loose a pool (and therefore your data), so it got me worrying.
I know that in my setting I don't have an UPS (yet) which is a requirement for FreeNAS and I was wondering about FreeNAS's behaviour when a power failure occurs.
So I did some tests focusing on that issue.
I started with some “basic” tests like:
Those tests were meant for me to see how FreeNAS reacts when a disk fails and what to do. They were quite instructive.
Then I started to perform more tests related to power failure:
Each time, I ran a scrub before and after to make sure everything was fine.
I performed those test more than once (with the exception of test 5 and 9, only once).
Each time the system started up without any problem and I didn’t get errors on the scrubs. I was somewhat surprised! I have a 3.3TB volume and I put about 10% of dummy data in it for the tests. I didn’t want the scrubs to take ages… ;-)
I was even impressed (during test 10 and 11) that it would restart the scrub were it left!
One “basic” test I still want to do is to try with a new USB stick to restart the system (of course, without a backup of the actual configuration).
An other “basic” test I performed was to take the USB stick and the hard disks and mount them on an other board.
What I don't really know is how relevant these tests are?
I only ran them a couple of times which might not be sufficient (but to be sufficient I'd have to run them 10s or 100s of times which is not easy).
What I tried to get out of these tests is a feeling on FreeNAS's behaviour in case of a power failure and to assess the risk of loosing a complete pool.
From the results I got, I would say: well it seems that FreeNAS handles it pretty well even in delicate situations (during resilvering).
But maybe I got lucky with the tests I performed...??
I'd be glad to have your opinion on that.
Some assumptions:
I'm not saying that I do not consider an UPS (I'm just weighting the probability of a power failure with the probability to loose the pool). In fact I'm planning to.
And of course I'm not saying either that I'm not doing backups! ;-)
And I do not know FreeNAS very well, I’m still reading the manual (and this forum which is great).
I built the following system:
- Motherboard: Supermicro X9SCM-f-o
- CPU: Intel Xeon 1220Lv2
- RAM: 2x8Go Kingston ECC KVR16E11/8I
- 6x1TB HDD (in RAIDZ2)
- FreeNAS version 9.2.0
- No encryption
- No compression
- Using CIFS
The system is running fine and before I use it for real (i.e. in production, but only for home usage), I'm experimenting with it to get use to FreeNAS (and trying to read the manual).
From a performance point of view, I'm very happy.
Internally I get about 300MB/s for writes and 400MB/s for reads (I used joeschmuck's tests in his post "Intel NIC vs RealTek NIC - Performance Testing", thanks).
And over the network (gigabit LAN) I get 90-100MB/s on large files (in my case I would have been happy with 60MB/s already!). And with small files I get between 40MB/s (2MB average file size) to 15MB/s (370kB average file size).
The power consumption is also quite good: about 60W when working, 50W idle (HDD not sleeping) and 20-25W for the mainboard and CPU.
As said, I used it first to experiment and get used to FreeNAS.
So I started to think about some tests to perform to see how FreeNAS would react and have an idea about its robustness.
On this forum I read some stories about how it seems easy to loose a pool (and therefore your data), so it got me worrying.
I know that in my setting I don't have an UPS (yet) which is a requirement for FreeNAS and I was wondering about FreeNAS's behaviour when a power failure occurs.
So I did some tests focusing on that issue.
I started with some “basic” tests like:
- Test 1: System powered off, take out one disk and switch the system on.
- Test 2: System powered off, take out two disks (RAIDZ2) and switch the system on.
- Test 3: System powered off, take out two disks, switch the system on (system degraded) delete some data (in this case a 100GB file), system off, reconnect the missing drives and restart the system.
- Test 4: System powered off, take out one disk, switch the system back on (system degraded), switch off, format the disk and put it back, restart the system.
Those tests were meant for me to see how FreeNAS reacts when a disk fails and what to do. They were quite instructive.
Then I started to perform more tests related to power failure:
- Test 5: System idle, no access to the volume, pull the plug.
- Test 6: Read files (i.e. copy from the NAS to a computer), pull the plug.
- Test 7: Write a big file (i.e. copy from a computer to the NAS), pull the plug.
- Test 8: Write small files, pull the plug.
- Test 9: Write files and system shutdown through the interface (I didn’t expect any problem here I just wanted to see the behaviour).
- Test 10: During a scrub, pull the plug.
- Test 11: During a resilvering, pull the plug.
Each time, I ran a scrub before and after to make sure everything was fine.
I performed those test more than once (with the exception of test 5 and 9, only once).
Each time the system started up without any problem and I didn’t get errors on the scrubs. I was somewhat surprised! I have a 3.3TB volume and I put about 10% of dummy data in it for the tests. I didn’t want the scrubs to take ages… ;-)
I was even impressed (during test 10 and 11) that it would restart the scrub were it left!
One “basic” test I still want to do is to try with a new USB stick to restart the system (of course, without a backup of the actual configuration).
An other “basic” test I performed was to take the USB stick and the hard disks and mount them on an other board.
What I don't really know is how relevant these tests are?
I only ran them a couple of times which might not be sufficient (but to be sufficient I'd have to run them 10s or 100s of times which is not easy).
What I tried to get out of these tests is a feeling on FreeNAS's behaviour in case of a power failure and to assess the risk of loosing a complete pool.
From the results I got, I would say: well it seems that FreeNAS handles it pretty well even in delicate situations (during resilvering).
But maybe I got lucky with the tests I performed...??
I'd be glad to have your opinion on that.
Some assumptions:
I'm not saying that I do not consider an UPS (I'm just weighting the probability of a power failure with the probability to loose the pool). In fact I'm planning to.
And of course I'm not saying either that I'm not doing backups! ;-)
And I do not know FreeNAS very well, I’m still reading the manual (and this forum which is great).