Re: [zfs-discuss] zfs send tape autoloaders?
Up to the moderator whether this will add anything: I dedicated the 2nd NICs on 2 V440s to transport the 9.5TB ZFS between SANs. configured a private subnet allowed rsh on the receiving V440. command: zfs send | (rsh receiving-host zfs receive ...) Took a whole week (7 days) and brought the receiving host's networking down to unusable. Could not ssh in to the first NIC, as the host would not respond before timing out. Some Oracle db connections stayed up, but were horribly slow. Gigabit Ethernet on a nice fast Cisco 4006 switch. Solaris 10, update 5 sending to Solaris 10 update 3, both V440s. I'm not going to do this ever again, I hope, so I'm not concerned with the why or how, but it was pretty bad. Seems like a zfsdump would be a good thing. -- David Strom On 1/13/2011 11:46 AM, David Magda wrote: On Thu, January 13, 2011 09:00, David Strom wrote: Moving to a new SAN, both LUNs will not be accessible at the same time. Thanks for the several replies I've received, sounds like the dd to tape mechanism is broken for zfs send, unless someone knows otherwise or has some trick? I'm just going to try a tar to tape then (maybe using dd), then, as I don't have any extended attributes/ACLs. Would appreciate any suggestions for block sizes for LTO5 tape drive, writing to LTO4 tapes (what I have). Might send it across the (Gigabit Ethernet) network to a server that's already on the new SAN, but I was trying to avoid hogging down the network or the other server's NIC. I've seen examples online for sending via network, involves piping zfs send over ssh to zfs receive, right? Could I maybe use rsh, if I enable it temporarily between the two hosts? If you don't already have a backup infrastructure (remember: RAID != backup), this may be a good opportunity. Something like Amanda or Bacula is gratis, and it could be useful for other circumstances. If this is a one-off it may not be worth it, but having important data without having (offline) backups is usually tempting fate. If you're just going to go to tape, then suntar/gnutar/star can write directly to it (or via rmt over the network), and there's no sense necessarily going through dd; 'tar' is short for TApe aRchiver after all. (However this is getting a bit OT for ZFS, and heading towards general sysadmin related.) ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] zfs send tape autoloaders?
On 02/16/11 09:50 AM, David Strom wrote: Up to the moderator whether this will add anything: I dedicated the 2nd NICs on 2 V440s to transport the 9.5TB ZFS between SANs. configured a private subnet allowed rsh on the receiving V440. command: zfs send | (rsh receiving-host zfs receive ...) Took a whole week (7 days) and brought the receiving host's networking down to unusable. Could not ssh in to the first NIC, as the host would not respond before timing out. Some Oracle db connections stayed up, but were horribly slow. Gigabit Ethernet on a nice fast Cisco 4006 switch. Solaris 10, update 5 sending to Solaris 10 update 3, both V440s. You were lucky to get away with that, the sending filesystems versions must have been old enough to be received by U3. ZFS has come a long way since those releases, we had a lot of lock-up problems with update 6, none now. -- Ian. ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] zfs send tape autoloaders?
On Thu, Jan 13, 2011 at 8:09 AM, Stephan Budach stephan.bud...@jvm.de wrote: Actually mbuffer does a great job for that, too. Whenever I am using mbuffer I am achieving much higher throughput then using ssh. Agreed, mbuffer seems to be required to get decent throughput. Using it on both ends of an SSH pipe (or at least at the sending side) helps smooth out performance more than you'd expect. -B -- Brandon High : bh...@freaks.com ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] zfs send tape autoloaders?
From: Richard Elling [mailto:richard.ell...@gmail.com] This means the current probability of any sha256 collision in all of the data in the whole world, using a ridiculously small block size, assuming all ... it doesn't matter. Other posters have found collisions and a collision without verify means silent data corruption. Do yourself a favor, enable verify. -- richard Somebody has found sha256 collisions? Perhaps it should be published to let the world know. http://en.wikipedia.org/wiki/SHA-2 says none have ever been found for either sha-1(160) or sha-2(256 or 512). ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] zfs send tape autoloaders?
Moving to a new SAN, both LUNs will not be accessible at the same time. Thanks for the several replies I've received, sounds like the dd to tape mechanism is broken for zfs send, unless someone knows otherwise or has some trick? I'm just going to try a tar to tape then (maybe using dd), then, as I don't have any extended attributes/ACLs. Would appreciate any suggestions for block sizes for LTO5 tape drive, writing to LTO4 tapes (what I have). Might send it across the (Gigabit Ethernet) network to a server that's already on the new SAN, but I was trying to avoid hogging down the network or the other server's NIC. I've seen examples online for sending via network, involves piping zfs send over ssh to zfs receive, right? Could I maybe use rsh, if I enable it temporarily between the two hosts? Thanks again, all. -- David Strom On 1/11/2011 11:43 PM, Ian Collins wrote: On 01/12/11 04:15 AM, David Strom wrote: I've used several tape autoloaders during my professional life. I recall that we can use ufsdump or tar or dd with at least some autoloaders where the autoloader can be set to automatically eject a tape when it's full load the next one. Has always worked OK whenever I tried it. I'm planning to try this with a new Quantum Superloader 3 with LTO5 tape drives and zfs send. I need to migrate a Solaris 10 host on a V440 to a new SAN. There is a 10 TB zfs pool filesystem that is comprised of 3 LUNs of different sizes put in the zfs pool, and it's almost full. Rather than copying the various sized Luns from the old SAN storage unit to the new one getting ZFS to recognize the pool, I thought it would be cleaner to dump the zfs filesystem to the tape autoloader restore it to a 10TB Lun. The users can live without this zfs filesystem for a few days. Why can't you just send directly to the new LUN? Create a new pool, send the data, export the old pool and rename. ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] zfs send tape autoloaders?
Am 13.01.11 15:00, schrieb David Strom: Moving to a new SAN, both LUNs will not be accessible at the same time. Thanks for the several replies I've received, sounds like the dd to tape mechanism is broken for zfs send, unless someone knows otherwise or has some trick? I'm just going to try a tar to tape then (maybe using dd), then, as I don't have any extended attributes/ACLs. Would appreciate any suggestions for block sizes for LTO5 tape drive, writing to LTO4 tapes (what I have). Might send it across the (Gigabit Ethernet) network to a server that's already on the new SAN, but I was trying to avoid hogging down the network or the other server's NIC. I've seen examples online for sending via network, involves piping zfs send over ssh to zfs receive, right? Could I maybe use rsh, if I enable it temporarily between the two hosts? Actually mbuffer does a great job for that, too. Whenever I am using mbuffer I am achieving much higher throughput then using ssh. ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] zfs send tape autoloaders?
On Thu, January 13, 2011 09:00, David Strom wrote: Moving to a new SAN, both LUNs will not be accessible at the same time. Thanks for the several replies I've received, sounds like the dd to tape mechanism is broken for zfs send, unless someone knows otherwise or has some trick? I'm just going to try a tar to tape then (maybe using dd), then, as I don't have any extended attributes/ACLs. Would appreciate any suggestions for block sizes for LTO5 tape drive, writing to LTO4 tapes (what I have). Might send it across the (Gigabit Ethernet) network to a server that's already on the new SAN, but I was trying to avoid hogging down the network or the other server's NIC. I've seen examples online for sending via network, involves piping zfs send over ssh to zfs receive, right? Could I maybe use rsh, if I enable it temporarily between the two hosts? If you don't already have a backup infrastructure (remember: RAID != backup), this may be a good opportunity. Something like Amanda or Bacula is gratis, and it could be useful for other circumstances. If this is a one-off it may not be worth it, but having important data without having (offline) backups is usually tempting fate. If you're just going to go to tape, then suntar/gnutar/star can write directly to it (or via rmt over the network), and there's no sense necessarily going through dd; 'tar' is short for TApe aRchiver after all. (However this is getting a bit OT for ZFS, and heading towards general sysadmin related.) ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] zfs send tape autoloaders?
On Jan 11, 2011, at 8:51 PM, Edward Ned Harvey wrote: heheheh, ok, I'll stop after this. ;-) Sorry for going on so long, but it was fun. In 2007, IDC estimated the size of the digital universe in 2010 would be 1 zettabyte. (10^21 bytes) This would be 2.5*10^18 blocks of 4000 bytes. http://www.emc.com/collateral/analyst-reports/expanding-digital-idc-white-pa per.pdf This means the current probability of any sha256 collision in all of the data in the whole world, using a ridiculously small block size, assuming all of the data is unique and therefore maximizing the probability of collision... 2.69 * 10^-41 ... hehehehehhe :-) It's not as unlikely as randomly picking a single atom in the whole planet, but still... ... it doesn't matter. Other posters have found collisions and a collision without verify means silent data corruption. Do yourself a favor, enable verify. -- richard ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
[zfs-discuss] zfs send tape autoloaders?
I've used several tape autoloaders during my professional life. I recall that we can use ufsdump or tar or dd with at least some autoloaders where the autoloader can be set to automatically eject a tape when it's full load the next one. Has always worked OK whenever I tried it. I'm planning to try this with a new Quantum Superloader 3 with LTO5 tape drives and zfs send. I need to migrate a Solaris 10 host on a V440 to a new SAN. There is a 10 TB zfs pool filesystem that is comprised of 3 LUNs of different sizes put in the zfs pool, and it's almost full. Rather than copying the various sized Luns from the old SAN storage unit to the new one getting ZFS to recognize the pool, I thought it would be cleaner to dump the zfs filesystem to the tape autoloader restore it to a 10TB Lun. The users can live without this zfs filesystem for a few days. So, has anyone had any experience with piping a zfs send through dd (so as to set the output blocksize for the tape drive) to a tape autoloader in autoload mode? Hope this makes sense? TIA. -- David Strom ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] zfs send tape autoloaders?
From: zfs-discuss-boun...@opensolaris.org [mailto:zfs-discuss- boun...@opensolaris.org] On Behalf Of David Strom So, has anyone had any experience with piping a zfs send through dd (so as to set the output blocksize for the tape drive) to a tape autoloader in autoload mode? Yes. I've had terrible experience doing that. For whatever reason, dd performance with zfs send was beyond horrible, although dd with other things was fine, and zfs send with other things was fine. I logged a support call with Sun, we worked on it some, reached a sneaking suspicion that there was a bug in dd, and they told me dd is not supported. I eventually gave up doing this, but I suspect putting a memory buffer in between the zfs send and the dd might help. Would that be buffer? or mbuffer? man pages. Can you connect to the old new SAN simultaneously? It would be immensely preferable (and faster) if you could send directly into the receive on the other. Also ... 10TB isn't amazingly huge these days. Maybe you should consider an esata card or two, and a few external 2T drive enclosures. If you're only using it for a temporary copy of your main pool, you can probably survive without any redundancy. It would cost around $600 to $800 but I'll tell you what, it's going to be a LOT faster than the tape drive. I think it will save you a day or two. ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] zfs send tape autoloaders?
On 01/12/11 04:15 AM, David Strom wrote: I've used several tape autoloaders during my professional life. I recall that we can use ufsdump or tar or dd with at least some autoloaders where the autoloader can be set to automatically eject a tape when it's full load the next one. Has always worked OK whenever I tried it. I'm planning to try this with a new Quantum Superloader 3 with LTO5 tape drives and zfs send. I need to migrate a Solaris 10 host on a V440 to a new SAN. There is a 10 TB zfs pool filesystem that is comprised of 3 LUNs of different sizes put in the zfs pool, and it's almost full. Rather than copying the various sized Luns from the old SAN storage unit to the new one getting ZFS to recognize the pool, I thought it would be cleaner to dump the zfs filesystem to the tape autoloader restore it to a 10TB Lun. The users can live without this zfs filesystem for a few days. Why can't you just send directly to the new LUN? Create a new pool, send the data, export the old pool and rename. -- Ian. ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] zfs send tape autoloaders?
heheheh, ok, I'll stop after this. ;-) Sorry for going on so long, but it was fun. In 2007, IDC estimated the size of the digital universe in 2010 would be 1 zettabyte. (10^21 bytes) This would be 2.5*10^18 blocks of 4000 bytes. http://www.emc.com/collateral/analyst-reports/expanding-digital-idc-white-pa per.pdf This means the current probability of any sha256 collision in all of the data in the whole world, using a ridiculously small block size, assuming all of the data is unique and therefore maximizing the probability of collision... 2.69 * 10^-41 ... hehehehehhe :-) It's not as unlikely as randomly picking a single atom in the whole planet, but still... ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
