question about SAS

[Ashley MLP Fangirl]

hi, just a few questions.

 

1. can i plug sata drives in my SAS board?

2. can i mix sata and sas drives together and have them work in a RAID array?

[ARikozuM]

SAS, if you're going with a server, can have a plane where the SAS connector splits off into multiple SATA+power ports. If your motherboard has SAS, I'd get a splitter and use those to connect nothing but SATA drives for cost reasons.

 

And, yes, you can mix them as far as I know.

 

@leadeater @Electronics Wizardy

[Ashley MLP Fangirl]

5 minutes ago, ARikozuM said:

SAS, if you're going with a server, can have a plane where the SAS connector splits off into multiple SATA+power ports. If your motherboard has SAS, I'd get a splitter and use those to connect nothing but SATA drives for cost reasons.

 

And, yes, you can mix them as far as I know.

 

@leadeater @Electronics Wizardy

i bought a second hand IBM system x3650. it has SAS drives (old ones) in it now, and i want to expand on them. can i just plug sata drives into the hdd bays?

[ARikozuM]

Straight? No. They use different plugs. You'd have to buy converters or add a new backplane that supports SAS to SATA.

[oskarha]

7 minutes ago, firelighter487 said:

i bought a second hand IBM system x3650. it has SAS drives (old ones) in it now, and i want to expand on them. can i just plug sata drives into the hdd bays?

A SAS controller (like the one in your IBM) is compatible with both SAS and SATA (in mixed configs as far as I know).

A SATA controller (like one on a consumer board), is only compatible with SATA.

[oskarha]

Just now, ARikozuM said:

Straight? No. They use different plugs. You'd have to buy converters or add a new backplane that supports SAS to SATA.

SATA drives will work with SAS cables (only SFF-8482, but its found on the back of every SAS drive) and fit in a SAS backplane, however SAS drives cannot be used in SATA backplanes or with SATA cables.

[Ashley MLP Fangirl]

1 minute ago, oskarha said:

SATA drives will work with SAS cables (only SFF-8482, but its found on the back of every SAS drive) and fit in a SAS backplane, however SAS drives cannot be used in SATA backplanes or with SATA cables.

so i can just put sata drives in the sleds and put them in then?

[oskarha]

Just now, firelighter487 said:

so i can just put sata drives in the sleds and put them in then?

Yup

[Ashley MLP Fangirl]

Just now, oskarha said:

Yup

okay, thanks! 

[oskarha]

Quote

SAS offers optional compatibility with SATA, versions 2 and later. This allows for SATA drives to be connected to most SAS backplanes or controllers. The reverse, connecting SAS drives to SATA backplanes, is not possible.

https://en.wikipedia.org/wiki/Serial_Attached_SCSI

[tt2468]

28 minutes ago, ARikozuM said:

SAS, if you're going with a server, can have a plane where the SAS connector splits off into multiple SATA+power ports. If your motherboard has SAS, I'd get a splitter and use those to connect nothing but SATA drives for cost reasons.

 

And, yes, you can mix them as far as I know.

 

@leadeater @Electronics Wizardy

On some RAID controllers you cannot create an array with SAS and SATA drives. Don't know which ones do this and which ones don't, all I know is that it has happened to me before.

[Ashley MLP Fangirl]

thanks!

[ARikozuM]

1 minute ago, tt2468 said:

On some RAID controllers you cannot create an array with SAS and SATA drives. Don't know which ones do this and which ones don't, all I know is that it has happened to me before.

As far as I know, you can. I've only got two servers with SAS backplanes and they use the same controller.

 

Edit: My knowledge isn't too broad which is why I mentioned the other guys.

[Ashley MLP Fangirl]

1 minute ago, tt2468 said:

On some RAID controllers you cannot create an array with SAS and SATA drives. Don't know which ones do this and which ones don't, all I know is that it has happened to me before.

okay, i guess ill find out tommorrow. 

[tt2468]

6 minutes ago, ARikozuM said:

As far as I know, you can. I've only got two servers with SAS backplanes and they use the same controller.

 

Edit: My knowledge isn't too broad which is why I mentioned the other guys.

 

7 minutes ago, tt2468 said:

On some RAID controllers

 

[leadeater]

2 hours ago, firelighter487 said:

hi, just a few questions.

 

1. can i plug sata drives in my SAS board?

2. can i mix sata and sas drives together and have them work in a RAID array?

1. Yes SAS controllers support SATA disks.

 

SATA controllers do not support SAS disks.

 

2. For hardware RAID on LSI controllers etc no you cannot have SAS disks and SATA disks in the same array, you have to create an array for each drive type.

 

For software RAIDs and the like yes you can.

[leadeater]

2 hours ago, firelighter487 said:

i bought a second hand IBM system x3650. it has SAS drives (old ones) in it now, and i want to expand on them. can i just plug sata drives into the hdd bays?

All you need to do is buy HDD sleds on ebay, $6 each, and 2.5" disks and put them in. That's what I do with my IBM server.

[NZLaurence]

The reason you cannot mix SAS and SATA drives in an array is because most hardware controllers require identical drives to form an array.

 

So you can't have say 4x500gb SAS and 4x500gb SATA in one 8 disk array. But you can have 2 separate 4 disk arrays on the same card.

 

In software raid (unraid, storage spaces) you can mix them because they are addressed as virtual disks. All the software cares about is the size. Even then its not recommended to mix types because they will have different performance profiles and you can end up with your 10k SAS disks idle because they are waiting on you 5400rpm green drive.

[Ashley MLP Fangirl]

10 hours ago, NZLaurence said:

The reason you cannot mix SAS and SATA drives in an array is because most hardware controllers require identical drives to form an array.

 

So you can't have say 4x500gb SAS and 4x500gb SATA in one 8 disk array. But you can have 2 separate 4 disk arrays on the same card.

 

In software raid (unraid, storage spaces) you can mix them because they are addressed as virtual disks. All the software cares about is the size. Even then its not recommended to mix types because they will have different performance profiles and you can end up with your 10k SAS disks idle because they are waiting on you 5400rpm green drive.

so it would be better to use 2 80gb sas disks in raid 0, 2 80gb sata disks in raid 0, and then striping them in software to create a 320gb volume? or just create 2 160gb volumes and use them seperately?

 

the reason i want to use 80gb disks is that's what i have spare, and i'm just experimenting with raid. everything will be backed up on another server with more modern drives in it. 

[NZLaurence]

54 minutes ago, firelighter487 said:

so it would be better to use 2 80gb sas disks in raid 0, 2 80gb sata disks in raid 0, and then striping them in software to create a 320gb volume? or just create 2 160gb volumes and use them seperately?

 

the reason i want to use 80gb disks is that's what i have spare, and i'm just experimenting with raid. everything will be backed up on another server with more modern drives in it. 

That would work but you will probably get better performance just doing it all in software. It will depend on your raid card. Test it and see how it goes.

[Ashley MLP Fangirl]

11 minutes ago, NZLaurence said:

That would work but you will probably get better performance just doing it all in software. It will depend on your raid card. Test it and see how it goes.

Ok, i'll test it then. Thanks for all the help!

[Ashley MLP Fangirl]

for those of you still following this, i can confirm that sata drives work in my servers  

[scottyseng]

3 hours ago, firelighter487 said:

for those of you still following this, i can confirm that sata drives work in my servers  

Yeah, it should be like that. I have a SATA array (6 x 4TB) and a SAS array (10 x 4TB). As mentioned above, you can't mix SATA and SAS drives in the same array (I tried), at least on a LSI MegaRAID card (I have the LSI MegaRAID 9260 8i).

[Ashley MLP Fangirl]

25 minutes ago, scottyseng said:

Yeah, it should be like that. I have a SATA array (6 x 4TB) and a SAS array (10 x 4TB). As mentioned above, you can't mix SATA and SAS drives in the same array (I tried), at least on a LSI MegaRAID card (I have the LSI MegaRAID 9260 8i).

yeah, i can't on mine either.