Does any one know how to, if at all possible currently, to export a block device via eSATA? i.e. how do I do something like iSCSI, but over eSATA?
I have a cheat ($15 probably?) media player at home (Egreat EG-M31B Network Media Tank - awesome little machine) that runs some flavor of Debian and can be connected to any PC via eSATA as an external HDD's. i.e. it exports the built-in HDD as a block device to the host (My laptop or PC).
Now, the question is, how can I do this on Linux? Would I need a different eSATA card than the on-board eSATA port on most motherboards? Or would the on-board one work?
The question is, how do I tell Linux to export a file system, or block device via the eSATA port?
If any one has attempted this before, then please share some knowledge or pointers on the subject. I couldn't find anything using google, but I may not necessarily have searched for the correct terms?
On 02/13/11 10:53 AM, Rudi Ahlers wrote:
Does any one know how to, if at all possible currently, to export a block device via eSATA? i.e. how do I do something like iSCSI, but over eSATA?
I have a cheat ($15 probably?) media player at home (Egreat EG-M31B Network Media Tank - awesome little machine) that runs some flavor of Debian and can be connected to any PC via eSATA as an external HDD's. i.e. it exports the built-in HDD as a block device to the host (My laptop or PC).
Now, the question is, how can I do this on Linux? Would I need a different eSATA card than the on-board eSATA port on most motherboards? Or would the on-board one work?
I suspect your media tank is doing something electrical, like idling its processor, and re-routing the sata port directly to the internal storage device, when its in this mode. I'm unaware of any SATA target drivers (as opposed to the normal initiator drivers in libata etc)
At Sun, 13 Feb 2011 11:00:39 -0800 CentOS mailing list centos@centos.org wrote:
On 02/13/11 10:53 AM, Rudi Ahlers wrote:
Does any one know how to, if at all possible currently, to export a block device via eSATA? i.e. how do I do something like iSCSI, but over eSATA?
I have a cheat ($15 probably?) media player at home (Egreat EG-M31B Network Media Tank - awesome little machine) that runs some flavor of Debian and can be connected to any PC via eSATA as an external HDD's. i.e. it exports the built-in HDD as a block device to the host (My laptop or PC).
Now, the question is, how can I do this on Linux? Would I need a different eSATA card than the on-board eSATA port on most motherboards? Or would the on-board one work?
I suspect your media tank is doing something electrical, like idling its processor, and re-routing the sata port directly to the internal storage device, when its in this mode. I'm unaware of any SATA target drivers (as opposed to the normal initiator drivers in libata etc)
More likely, it is running some custom software the connects to the exposed port (which is probably not a typical PC SATA port -- it would be wired like a Hard Drive's SATA connector (opposite gender, opposite signal directions, etc.). The custom software presents itself on this port like it was a hard drive and implements some sort of logical hard drive based on the actual internal hard drive -- not really much different from a USB connected mp3 player or camera -- the USB connected mp3 players / camera are just using a different physical interface (USB), but the logic is the same. Again, the USB port on these devices is 'wired' the opposite from the USB port on a normal PC and the logic behind it is also opposite (you cannot really connect a USB port of one PC to the USB port of another -- there is no such thing as a USB 'cross over' (Ethernet) or null-modem (RS232) cable in the USB (or firewire) world). The processor in the little box is implementing much that same sort of processing that goes on inside the micro processor on the controller board of a hard drive -- modern hard drive controller boards are really a full fledged little computer running a very special program that implements the drive end of the mass storage interface (SCSI, SATA, PATA, etc.). The media tank is just taking this to a different level.
CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
On Sun, Feb 13, 2011 at 9:44 PM, Robert Heller heller@deepsoft.com wrote:
At Sun, 13 Feb 2011 11:00:39 -0800 CentOS mailing list centos@centos.org wrote:
On 02/13/11 10:53 AM, Rudi Ahlers wrote:
Does any one know how to, if at all possible currently, to export a block device via eSATA? i.e. how do I do something like iSCSI, but over eSATA?
I have a cheat ($15 probably?) media player at home (Egreat EG-M31B Network Media Tank - awesome little machine) that runs some flavor of Debian and can be connected to any PC via eSATA as an external HDD's. i.e. it exports the built-in HDD as a block device to the host (My laptop or PC).
Now, the question is, how can I do this on Linux? Would I need a different eSATA card than the on-board eSATA port on most motherboards? Or would the on-board one work?
I suspect your media tank is doing something electrical, like idling its processor, and re-routing the sata port directly to the internal storage device, when its in this mode. I'm unaware of any SATA target drivers (as opposed to the normal initiator drivers in libata etc)
More likely, it is running some custom software the connects to the exposed port (which is probably not a typical PC SATA port -- it would be wired like a Hard Drive's SATA connector (opposite gender, opposite signal directions, etc.). The custom software presents itself on this port like it was a hard drive and implements some sort of logical hard drive based on the actual internal hard drive -- not really much different from a USB connected mp3 player or camera -- the USB connected mp3 players / camera are just using a different physical interface (USB), but the logic is the same. Again, the USB port on these devices is 'wired' the opposite from the USB port on a normal PC and the logic behind it is also opposite (you cannot really connect a USB port of one PC to the USB port of another -- there is no such thing as a USB 'cross over' (Ethernet) or null-modem (RS232) cable in the USB (or firewire) world). The processor in the little box is implementing much that same sort of processing that goes on inside the micro processor on the controller board of a hard drive -- modern hard drive controller boards are really a full fledged little computer running a very special program that implements the drive end of the mass storage interface (SCSI, SATA, PATA, etc.). The media tank is just taking this to a different level.
Sure, I understand what you're saying, but the question is: If they can do it with a cheap device like this, then surely one should be able todo it with a normal / server motherboard? Obviously they won't tell us their secrets, so I need to dig around to see how todo it myself. This particular device has a eSATA slave + eSATA Master mode. i.e. I can connect another device to this one and they both work together, and then when I connect the first one to my PC, I have 2 HDD's - i.e. a cheap JBOD implementation.
I'm trying to see if I can setup a Linux JBOD on a server chassis with say 16 HDD's or something, and then connect it to another server via eSATA - i.e. building a cheap scalable SAN.
P.S. You actually do get USB cross-over cables: http://en.kioskea.net/faq/342-connecting-two-computers-with-a-usb-cable - they work quite well. They're not as fast a gigabit but works very well for older PC's without LAN.
At Sun, 13 Feb 2011 21:58:11 +0200 CentOS mailing list centos@centos.org wrote:
On Sun, Feb 13, 2011 at 9:44 PM, Robert Heller heller@deepsoft.com wrote:
At Sun, 13 Feb 2011 11:00:39 -0800 CentOS mailing list centos@centos.org wrote:
On 02/13/11 10:53 AM, Rudi Ahlers wrote:
Does any one know how to, if at all possible currently, to export a block device via eSATA? i.e. how do I do something like iSCSI, but over eSATA?
I have a cheat ($15 probably?) media player at home (Egreat EG-M31B Network Media Tank - awesome little machine) that runs some flavor of Debian and can be connected to any PC via eSATA as an external HDD's. i.e. it exports the built-in HDD as a block device to the host (My laptop or PC).
Now, the question is, how can I do this on Linux? Would I need a different eSATA card than the on-board eSATA port on most motherboards? Or would the on-board one work?
I suspect your media tank is doing something electrical, like idling its processor, and re-routing the sata port directly to the internal storage device, when its in this mode. I'm unaware of any SATA target drivers (as opposed to the normal initiator drivers in libata etc)
More likely, it is running some custom software the connects to the exposed port (which is probably not a typical PC SATA port -- it would be wired like a Hard Drive's SATA connector (opposite gender, opposite signal directions, etc.). The custom software presents itself on this port like it was a hard drive and implements some sort of logical hard drive based on the actual internal hard drive -- not really much different from a USB connected mp3 player or camera -- the USB connected mp3 players / camera are just using a different physical interface (USB), but the logic is the same. Again, the USB port on these devices is 'wired' the opposite from the USB port on a normal PC and the logic behind it is also opposite (you cannot really connect a USB port of one PC to the USB port of another -- there is no such thing as a USB 'cross over' (Ethernet) or null-modem (RS232) cable in the USB (or firewire) world). The processor in the little box is implementing much that same sort of processing that goes on inside the micro processor on the controller board of a hard drive -- modern hard drive controller boards are really a full fledged little computer running a very special program that implements the drive end of the mass storage interface (SCSI, SATA, PATA, etc.). The media tank is just taking this to a different level.
Sure, I understand what you're saying, but the question is: If they can do it with a cheap device like this, then surely one should be able todo it with a normal / server motherboard? Obviously they won't tell us their secrets, so I need to dig around to see how todo it myself. This particular device has a eSATA slave + eSATA Master mode. i.e. I can connect another device to this one and they both work together, and then when I connect the first one to my PC, I have 2 HDD's - i.e. a cheap JBOD implementation.
You probably can't do it with 'a normal / server motherboard'. The SATA / eSATA ports on such a board are 'host' ports. You would need a 'disk' port, which is *electrically* different -- it is no different than with USB or Firewire devices. There is the 'host' side and there is the 'device' side. They are different.
I'm trying to see if I can setup a Linux JBOD on a server chassis with say 16 HDD's or something, and then connect it to another server via eSATA - i.e. building a cheap scalable SAN.
P.S. You actually do get USB cross-over cables: http://en.kioskea.net/faq/342-connecting-two-computers-with-a-usb-cable
- they work quite well. They're not as fast a gigabit but works very
well for older PC's without LAN.
On 02/13/11 12:28 PM, Robert Heller wrote:
it is no different than with USB or Firewire devices. There is the 'host' side and there is the 'device' side. They are different.
actually, firewire is a peer to peer bus, like ethernet. there's no 'host' or 'device', there is just firewire.
</pendantic>
On 2/13/11 1:58 PM, Rudi Ahlers wrote:
Sure, I understand what you're saying, but the question is: If they can do it with a cheap device like this, then surely one should be able todo it with a normal / server motherboard? Obviously they won't tell us their secrets, so I need to dig around to see how todo it myself. This particular device has a eSATA slave + eSATA Master mode. i.e. I can connect another device to this one and they both work together, and then when I connect the first one to my PC, I have 2 HDD's - i.e. a cheap JBOD implementation.
If you are going to pass eSATA straight through, why would you want the other motherboard involved at all instead of just using an external eSata enclosure?
I'm trying to see if I can setup a Linux JBOD on a server chassis with say 16 HDD's or something, and then connect it to another server via eSATA - i.e. building a cheap scalable SAN.
It might make sense to RAID a bunch of disks locally, and export the combined device as iscsi.
P.S. You actually do get USB cross-over cables: http://en.kioskea.net/faq/342-connecting-two-computers-with-a-usb-cable
- they work quite well. They're not as fast a gigabit but works very
well for older PC's without LAN.
I thought those were really implemented as back-to-back ethernet converters.
On Sun, Feb 13, 2011 at 11:10 PM, Les Mikesell lesmikesell@gmail.com wrote:
On 2/13/11 1:58 PM, Rudi Ahlers wrote:
Sure, I understand what you're saying, but the question is: If they can do it with a cheap device like this, then surely one should be able todo it with a normal / server motherboard? Obviously they won't tell us their secrets, so I need to dig around to see how todo it myself. This particular device has a eSATA slave + eSATA Master mode. i.e. I can connect another device to this one and they both work together, and then when I connect the first one to my PC, I have 2 HDD's - i.e. a cheap JBOD implementation.
If you are going to pass eSATA straight through, why would you want the other motherboard involved at all instead of just using an external eSata enclosure?
I'm trying to build a dense eSATA enclosure with say 16 or 24 drives :)
I'm trying to see if I can setup a Linux JBOD on a server chassis with say 16 HDD's or something, and then connect it to another server via eSATA - i.e. building a cheap scalable SAN.
It might make sense to RAID a bunch of disks locally, and export the combined device as iscsi.
The 1GBE LAN is a bit slow. SATA can push 6GBe, which is 6 times faster than 1GBe. And, 6 ports on a LAN switch is a waste. Our 10GBe switches are saturated (all ports filled) and very expensive. So I'm looking at cheaper options, and thought eSATA could do the trick quite well.
P.S. You actually do get USB cross-over cables: http://en.kioskea.net/faq/342-connecting-two-computers-with-a-usb-cable
- they work quite well. They're not as fast a gigabit but works very
well for older PC's without LAN.
I thought those were really implemented as back-to-back ethernet converters.
Yes, probably. But they work over USB so it's very handy.
-- Les Mikesell lesmikesell@gmail.com _______________________________________________ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
On 02/13/11 1:21 PM, Rudi Ahlers wrote:
I'm trying to build a dense eSATA enclosure with say 16 or 24 drives :)
thats a stunningly bad way to go about it.
A) if you want JBOD, use a SAS/SATA enclosure with a SAS host card, as SATA doesn't support multichannel multiplexing. or B) if you want a SAN, use iSCSI or FCoE or something. or C) if you want a NAS, use NFS. this is the best solution for many applications.
On Sun, Feb 13, 2011 at 11:35 PM, John R Pierce pierce@hogranch.com wrote:
On 02/13/11 1:21 PM, Rudi Ahlers wrote:
I'm trying to build a dense eSATA enclosure with say 16 or 24 drives :)
thats a stunningly bad way to go about it.
A) if you want JBOD, use a SAS/SATA enclosure with a SAS host card, as SATA doesn't support multichannel multiplexing.
mmm, I didn't think of this :)
or B) if you want a SAN, use iSCSI or FCoE or something.
As I said, I'm trying todo something cheaper. These are super expensive in our country.
or C) if you want a NAS, use NFS. this is the best solution for many applications.
We already use iSCSI, which is a bit quicker than NFS
I'm merely exploring this "new" technology, seeing as so many vendor incorporate it into cheap NAS devices (which are normally limited to 2 - 5 drives) to see if it could actually be used on a bigger scale.
CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
On Feb 13, 2011, at 4:59 PM, Rudi Ahlers Rudi@SoftDux.com wrote:
On Sun, Feb 13, 2011 at 11:35 PM, John R Pierce pierce@hogranch.com wrote:
On 02/13/11 1:21 PM, Rudi Ahlers wrote:
I'm trying to build a dense eSATA enclosure with say 16 or 24 drives :)
thats a stunningly bad way to go about it.
A) if you want JBOD, use a SAS/SATA enclosure with a SAS host card, as SATA doesn't support multichannel multiplexing.
mmm, I didn't think of this :)
Dell has the MD1120 which is a 24 bay 2.5" SAS/SATA enclosure. I think it goes for $3000 plus cost of disk drives.
If you want to go cheaper I believe Supermicro makes a 16 drive chassis that is meant for a server, but can be made into an external enclosure, or an iSCSI/NFS/CIFS storage server.
-Ross
On Mon, Feb 14, 2011 at 4:44 AM, Ross Walker rswwalker@gmail.com wrote:
On Feb 13, 2011, at 4:59 PM, Rudi Ahlers Rudi@SoftDux.com wrote:
On Sun, Feb 13, 2011 at 11:35 PM, John R Pierce pierce@hogranch.com wrote:
On 02/13/11 1:21 PM, Rudi Ahlers wrote:
I'm trying to build a dense eSATA enclosure with say 16 or 24 drives :)
thats a stunningly bad way to go about it.
A) if you want JBOD, use a SAS/SATA enclosure with a SAS host card, as SATA doesn't support multichannel multiplexing.
mmm, I didn't think of this :)
Dell has the MD1120 which is a 24 bay 2.5" SAS/SATA enclosure. I think it goes for $3000 plus cost of disk drives.
If you want to go cheaper I believe Supermicro makes a 16 drive chassis that is meant for a server, but can be made into an external enclosure, or an iSCSI/NFS/CIFS storage server.
-Ross
Thanx Ross.
We got those 16 drive SuperMicro chassis, which is what I want to use, and they're already running FreeNAS which offers iSCSI & NFS.
I just had this idea of exploring eSATA since most machines already have an eSATA port. So if I don't get this working, it's not a big deal. But, I think it could be a cheap alternative to SAS / FC interconnect.
On Feb 14, 2011, at 2:27 AM, Rudi Ahlers Rudi@SoftDux.com wrote:
On Mon, Feb 14, 2011 at 4:44 AM, Ross Walker rswwalker@gmail.com wrote:
On Feb 13, 2011, at 4:59 PM, Rudi Ahlers Rudi@SoftDux.com wrote:
On Sun, Feb 13, 2011 at 11:35 PM, John R Pierce pierce@hogranch.com wrote:
On 02/13/11 1:21 PM, Rudi Ahlers wrote:
I'm trying to build a dense eSATA enclosure with say 16 or 24 drives :)
thats a stunningly bad way to go about it.
A) if you want JBOD, use a SAS/SATA enclosure with a SAS host card, as SATA doesn't support multichannel multiplexing.
mmm, I didn't think of this :)
Dell has the MD1120 which is a 24 bay 2.5" SAS/SATA enclosure. I think it goes for $3000 plus cost of disk drives.
If you want to go cheaper I believe Supermicro makes a 16 drive chassis that is meant for a server, but can be made into an external enclosure, or an iSCSI/NFS/CIFS storage server.
-Ross
Thanx Ross.
We got those 16 drive SuperMicro chassis, which is what I want to use, and they're already running FreeNAS which offers iSCSI & NFS.
I just had this idea of exploring eSATA since most machines already have an eSATA port. So if I don't get this working, it's not a big deal. But, I think it could be a cheap alternative to SAS / FC interconnect.
Then take the supermicro chassis without motherboard, get an eSATA to SATA connector, connect it to a port multiplier and then to the 16 drives and see if that works.
-Ross
On 2/14/11 7:57 AM, Ross Walker wrote:
I just had this idea of exploring eSATA since most machines already have an eSATA port. So if I don't get this working, it's not a big deal. But, I think it could be a cheap alternative to SAS / FC interconnect.
Then take the supermicro chassis without motherboard, get an eSATA to SATA connector, connect it to a port multiplier and then to the 16 drives and see if that works.
Are the Centos drivers for SATA port multiplexers solid these days? Are there any differences?
I've started building a JBOD out of a Supermicro case for expanding the available storage on my home network. So I have a few comments about what I learned so far about using Supermicro as JBODs.
Supermicro has several multi bay chassis as part of their current product line but I'm looking to do this on a budget so I took the ebay route. I found some reasonably priced 12 bay cases use "Supermicro 12 bay" as your search criteria. I found a good deal that cost a tad over two hundred bucks. I was a bit drawn to the Supermicro chassis since they make a power card that allows the front power button to control the power supply without a motherboard. It is designed with the intention of using the cases as JBODs.
CSE-PTJBOD-CB1
The backplane port(s) can be mapped to the outside with something like this:
http://www.pc-pitstop.com/sas_cables_adapters/
Since my case doesn't have an expander backplane and is instead comprised of 12 individual SATA ports In my case I'll end up with three ports exposed since each connector supports 4 drives. If you have an expander backplane it could be as simple as a single cable.
From there you'll connect the external SAS ports to a SATA/SAS
adapter. It is possible to get SATA/SAS cards that already have externally available SFF-8088 ports or if they are all internal you can expose them externally by using the same SFF-8088 PCI brackets on the server side.
I intend on hooking this JBOD up to a couple of computers which is why I am not just putting a motherboard and running it as a full on server.
On a side not since this is for home usage a few things I plan on doing to make it better suited is replacing the hotswap 800 watt power supply with something high efficiency and at least half the watts and use quieter fans possibly putting them on some kind of speed control
jeff
On Mon, Feb 14, 2011 at 8:05 AM, Les Mikesell lesmikesell@gmail.com wrote:
On 2/14/11 7:57 AM, Ross Walker wrote:
I just had this idea of exploring eSATA since most machines already have an eSATA port. So if I don't get this working, it's not a big deal. But, I think it could be a cheap alternative to SAS / FC interconnect.
Then take the supermicro chassis without motherboard, get an eSATA to SATA connector, connect it to a port multiplier and then to the 16 drives and see if that works.
Are the Centos drivers for SATA port multiplexers solid these days? Are there any differences?
-- Les Mikesell lesmikesell@gmail.com _______________________________________________ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
On Tue, Feb 15, 2011 at 9:49 AM, Jeff Hefner jeffhefner@gmail.com wrote:
I've started building a JBOD out of a Supermicro case for expanding the available storage on my home network. So I have a few comments about what I learned so far about using Supermicro as JBODs.
Supermicro has several multi bay chassis as part of their current product line but I'm looking to do this on a budget so I took the ebay route. I found some reasonably priced 12 bay cases use "Supermicro 12 bay" as your search criteria. I found a good deal that cost a tad over two hundred bucks. I was a bit drawn to the Supermicro chassis since they make a power card that allows the front power button to control the power supply without a motherboard. It is designed with the intention of using the cases as JBODs.
CSE-PTJBOD-CB1
The backplane port(s) can be mapped to the outside with something like this:
http://www.pc-pitstop.com/sas_cables_adapters/
Since my case doesn't have an expander backplane and is instead comprised of 12 individual SATA ports In my case I'll end up with three ports exposed since each connector supports 4 drives. If you have an expander backplane it could be as simple as a single cable.
From there you'll connect the external SAS ports to a SATA/SAS
adapter. It is possible to get SATA/SAS cards that already have externally available SFF-8088 ports or if they are all internal you can expose them externally by using the same SFF-8088 PCI brackets on the server side.
I intend on hooking this JBOD up to a couple of computers which is why I am not just putting a motherboard and running it as a full on server.
On a side not since this is for home usage a few things I plan on doing to make it better suited is replacing the hotswap 800 watt power supply with something high efficiency and at least half the watts and use quieter fans possibly putting them on some kind of speed control
jeff
Jeff, what you did is exactly what I want todo as well :)
And, while thinking about how todo it on the cheap, I thought about using eSATA for it.
The only options I could find what SATA port replicators, but they're limited to 4/5 ports each. And I can't find a supplier in our country for them, so I guess I'll have to import them, which will end up costing an arm and a leg again. Our import duties are expensive.
Which SAS expander did you use? Our local SuperMicro suppliers have limited products available so if I need something that they don't have, I'll have to convince them to get it for me.
Upto now they've sold me full blown servers with iSCSI interconnects, which is expensive if I don't actually use the motherboard, CPU or RAM for anything useful.
I'm also considering going another route, but it seems that suppliers in our country simply don't like selling loose components. Why, I don't know, but I guess someone has to milk the poor clients of their money.
-
Jeff Hefner -
John R Pierce -
Les Mikesell -
Robert Heller -
Ross Walker -
Rudi Ahlers