ZFS Memory Requirements

[Livesundersink]

I am currently sourcing parts for a home server ZFS build, i have read that it requires 1gb of memory for every tb of storage space on the array, should i start with the max amount of ram that the motherboard will allow? or should i add more at a later time? also is it possible to add more memory after the array has been created and if so how easy is it to do?

[Streetguru]

2 minutes ago, Livesundersink said:

I am currently sourcing parts for a home server ZFS build, i have read that it requires 1gb of memory for every tb of storage space on the array, should i start with the max amount of ram that the motherboard will allow? or should i add more at a later time? also is it possible to add more memory after the array has been created and if so how easy is it to do?

Probably don't need more than 16GBs unless you have a ton of TBs

[Livesundersink]

2 minutes ago, Streetguru said:

Probably don't need more than 16GBs unless you have a ton of TBs

10-20tb will be the initial size, do you know how to add more memory later on?

[Streetguru]

Just now, Livesundersink said:

10-20tb will be the initial size, do you know how to add more memory later on?

Just shove more into the system?

[Electronics Wizardy]

13 minutes ago, Livesundersink said:

I am currently sourcing parts for a home server ZFS build, i have read that it requires 1gb of memory for every tb of storage space on the array, should i start with the max amount of ram that the motherboard will allow? or should i add more at a later time? also is it possible to add more memory after the array has been created and if so how easy is it to do?

the 1gb per tb is bs.

 

Unless your using dedup it doesn't need more ram than any other filesystem and the extra ram is used as a disk cache.

 

Ram depends on the use, what are you using the storage for?

[Livesundersink]

2 minutes ago, Electronics Wizardy said:

the 1gb per tb is bs.

 

Unless your using dedup it doesn't need more ram than any other filesystem and the extra ram is used as a disk cache.

 

Ram depends on the use, what are you using the storage for?

just as a local file server and backup

[Electronics Wizardy]

Just now, Livesundersink said:

just as a local file server and backup

then like 4gb will be fine for a home server, depending on speed needs, more is always better.

 

What network speed are you using? What drives? What hardware?

[Livesundersink]

Just now, Electronics Wizardy said:

then like 4gb will be fine for a home server, depending on speed needs, more is always better.

 

What network speed are you using? What drives? What hardware?

1 gigabit network speed, drives will be a mixture of Seagate Ironwolf Pro's and WD Red Pro's, still haven't finalised what other hardware will be used, will know more on that in about 2 weeks

[Electronics Wizardy]

2 hours ago, Livesundersink said:

1 gigabit network speed, drives will be a mixture of Seagate Ironwolf Pro's and WD Red Pro's, still haven't finalised what other hardware will be used, will know more on that in about 2 weeks

Do you already have these drives? thats a odd choice it seems of drives.

 

filling a 1gb network is easy, almost any semi modern hardware can do this.

[Livesundersink]

1 hour ago, Electronics Wizardy said:

Do you already have these drives? thats a odd choice it seems of drives.

 

filling a 1gb network is easy, almost any semi modern hardware can do this.

I was told by a friend whos opinion i trust explicitly that i should use drives that are meant to be used in a network environment.

 

I will have to speak with him about the network speed. I'm not entirely sure about speed will be used

[Electronics Wizardy]

6 minutes ago, Livesundersink said:

I was told by a friend whos opinion i trust explicitly that i should use drives that are meant to be used in a network environment.

 

I will have to speak with him about the network speed. I'm not entirely sure about speed will be used

For a home server I don't see the point of a red pro, the normal red is fine.

 

ZFS doesn't care much about the tler in nas drives, but they won't hurt. I personally would get those 8tb externals, but get what you want.

 

Why mix drives? normally its best practice to have one model of drives in an array.

[leadeater]

6 hours ago, Livesundersink said:

Seagate Ironwolf Pro's and WD Red Pro's

The non Pro versions of the disks are rated for 24/7 NAS usage as well and have optimized firmware for it. The Pro versions are for NAS's that'll have more than 8 HDDs in it though normal Reds and Ironwolfs will go up to 16 just fine and even 24 in a good mounting that doesn't transfer too much vibration.

 

The Pros have extra vibration compensation and you can just use anti-vibration screws and save a ton of money.

 

Quote

Unlike WD Red drives, the WD Red Pro drives are rated for up to 16 drive configurations due to the addition of RAFF Technology (Rotary Acceleration Feed Forward) which is an active vibration protection previously found only in WD's Datacenter drives. However, the use of RAFF makes them louder and hotter than the Red drives so they may not be the best option for most desktop systems.

 

[Livesundersink]

On 8/26/2018 at 4:31 PM, Electronics Wizardy said:

Why mix drives? normally its best practice to have one model of drives in an array.

My friend told me to space out the purchase of the drives, to buy each from a different store and mix between Seagate and WD to reduce the chances of receiving defective drives. He explained that if i buy them all the same model and from the same store all at once then i am at risk of data loss if all of those drives are faulty by way of being from a defective batch of drives.

[Electronics Wizardy]

20 minutes ago, Livesundersink said:

My friend told me to space out the purchase of the drives, to buy each from a different store and mix between Seagate and WD to reduce the chances of receiving defective drives. He explained that if i buy them all the same model and from the same store all at once then i am at risk of data loss if all of those drives are faulty by way of being from a defective batch of drives.

bad batches aren't really needed these days, and failure time varies in a batch. But you also need to have backups if this does happen. I would just get one type though. Just get reds or ironwolfs. Id get what ever is cheaper