If anyone is wanting to experiment with SAN technology, but finding iSCSI too fiddly, have a look at AOE (ATA over Ethernet). There is a software AoE server, and the kernel client is already in 2.6.11. I use AOE root on dom0, and on the block devices exported to the other domains (eg dom0 exports AOE devices, the other domains don''t do AOE themselves). This allows for domain migration to work nicely. Have a look at: http://aoetools.sourceforge.net/ (tools + software server) And: http://www.coraid.com/ (hardware AOE server) I can post some details for getting Debian root on AOE if anyone is interested. James _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
On 22 May 2005, at 05:51, James Harper wrote:> If anyone is wanting to experiment with SAN technology, but finding > iSCSI too fiddly, have a look at AOE (ATA over Ethernet). There is a > software AoE server, and the kernel client is already in 2.6.11. > > I use AOE root on dom0, and on the block devices exported to the other > domains (eg dom0 exports AOE devices, the other domains don''t do AOE > themselves). This allows for domain migration to work nicely.I''m surprised that the protocol packets don''t include an end-to-end checksum. If the packets pass through a switch that occasionally garbles packets then you could end up committing erroneous sectors to disc. On the other hand, if this is a significant problem then NFS/iscsi IP checksumming may not save your data either, since the IP checksum is so weak. For large volumes of data you care about the integrity of, you probably really want an end-to-end CRC. -- Keir _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
On 22 May 2005, at 08:48, Keir Fraser wrote:> I''m surprised that the protocol packets don''t include an end-to-end > checksum. If the packets pass through a switch that occasionally > garbles packets then you could end up committing erroneous sectors to > disc. > > On the other hand, if this is a significant problem then NFS/iscsi IP > checksumming may not save your data either, since the IP checksum is > so weak. For large volumes of data you care about the integrity of, > you probably really want an end-to-end CRC.Oops. The Ethernet CRC is end-to-end on a LAN, even if it''s switched. :-) -- Keir _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
On 5/22/05, James Harper <james.harper@bendigoit.com.au> wrote:> If anyone is wanting to experiment with SAN technology, but finding > iSCSI too fiddly, have a look at AOE (ATA over Ethernet). There is a > software AoE server, and the kernel client is already in 2.6.11. > > I use AOE root on dom0, and on the block devices exported to the other > domains (eg dom0 exports AOE devices, the other domains don''t do AOE > themselves). This allows for domain migration to work nicely.Have you ever tried gnbd? How does this compare to gnbd? We''ve used gnbd in exactly the same setup. christian _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
I''ve tried nbd, and possibly enbd (can''t remember if I got that working or not). At the time I was using a server which had performed okay as Windows 2000 Server for some time. When running Linux though, it crashed all the time. The problem turned out to be a bad stick of memory, but by then I''d been through a few attempts of iSCSI and nbd and had cursed their unreliability (obviously, it turned out to be the server itself in the end). Assuming a working AoE server on the same L2 network, you simply need to have an ''up'' network adapter, and load the AoE module. You don''t even need a TCP/IP stack running. Apart from MAC filtering, there is no security, so it should really be on its own Ethernet segment, or VLAN. HTH James> -----Original Message----- > From: Christian Limpach [mailto:christian.limpach@gmail.com] > Sent: Sunday, 22 May 2005 18:30 > To: James Harper > Cc: xen-devel@lists.xensource.com > Subject: Re: [Xen-devel] AOE > > On 5/22/05, James Harper <james.harper@bendigoit.com.au> wrote: > > If anyone is wanting to experiment with SAN technology, but finding > > iSCSI too fiddly, have a look at AOE (ATA over Ethernet). There is a > > software AoE server, and the kernel client is already in 2.6.11. > > > > I use AOE root on dom0, and on the block devices exported to theother> > domains (eg dom0 exports AOE devices, the other domains don''t do AOE > > themselves). This allows for domain migration to work nicely. > > Have you ever tried gnbd? How does this compare to gnbd? We''ve used > gnbd in exactly the same setup. > > christian_______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel