Ok, so here''s my "situation" that I may or may not run into in the future. Currently I have 3x120GB PATA drives in a RAID-Z as part of my zfs pool. I plan on adding 2x320GB SATA drives in the immediate future to the same pool as a raid-1. Here''s where it gets tricky. In the future, in a perfect world, I''d like to pick up a third 320GB SATA drive to make a RAID-Z out of those as well. So what would be the outcome of the following two scenarios: 1. I have the pool as it stands, but it''s taking up less space than the total free space on the initial PATA RAID-Z. I remove the RAID-1 SATA, make a RAID-Z out of them, and then re-add them to the pool. Can I do this without losing any data? Assuming some is striped across the RAID-1, can it recover gracefully? 2. I have the pool as it stands, but it''s taking up MORE space than the total free on the initial PATA RAID-Z. I remove the RAID-1 again, to make a RAID-Z. What''s going to happen to that data that is > the RAID-Z can store? Do I lose data? Does it tell me no way, and not allow me to remove the RAID-1 from the pool without a big "idiot you''re about to lose all your data" message? If there''s anything that doesn''t make sense, please let me know and I''ll try to clarify. Thanks, Tim This message posted from opensolaris.org
James Dickens
2006-Sep-02 01:51 UTC
[zfs-discuss] Need some input on a theoretical situation
On 9/1/06, Tim Cook <tim.cook at qlogic.com> wrote:> Ok, so here''s my "situation" that I may or may not run into in the future. > > Currently I have 3x120GB PATA drives in a RAID-Z as part of my zfs pool. I plan on adding 2x320GB SATA drives in the immediate future to the same pool as a raid-1. Here''s where it gets tricky. In the future, in a perfect world, I''d like to pick up a third 320GB SATA drive to make a RAID-Z out of those as well. So what would be the outcome of the following two scenarios: >the best solution is to put the 3rd 320GB drive on a credit card and get all 3 at once, then you don''t have the headache. or wait long enough and they may have the utility to resise raidz pools. the other option would be if they would implement a 3 disk raidz pool with one drive degraded. then you could break the mirror, make the 3 disk raidz pool running in degraded mode. then copy data over, and then add the 3rd disk to the pool. perhaps that would be a good RFE "create a raidz with N-1 disks so it runs in degraded mode" to cope with solutions like these. James Dickens uadmin.blogspot.com> 1. I have the pool as it stands, but it''s taking up less space than the total free space on the initial PATA RAID-Z. I remove the RAID-1 SATA, make a RAID-Z out of them, and then re-add them to the pool. Can I do this without losing any data? Assuming some is striped across the RAID-1, can it recover gracefully? > > 2. I have the pool as it stands, but it''s taking up MORE space than the total free on the initial PATA RAID-Z. I remove the RAID-1 again, to make a RAID-Z. What''s going to happen to that data that is > the RAID-Z can store? Do I lose data? Does it tell me no way, and not allow me to remove the RAID-1 from the pool without a big "idiot you''re about to lose all your data" message? > > If there''s anything that doesn''t make sense, please let me know and I''ll try to clarify. > > Thanks, > > Tim > > > This message posted from opensolaris.org > _______________________________________________ > zfs-discuss mailing list > zfs-discuss at opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss >
Wee Yeh Tan
2006-Sep-02 07:17 UTC
[zfs-discuss] Need some input on a theoretical situation
I imagine that extending "zpool attach" to attach new devices to RAID-Z sets would be exactly what you want. Of course, I am wholy unaware of the implementation details so the technical difficulties might be tremendrous. In any case, there is no removing device yet so either senarios listed by Tim will require re-building the entire zpool. -- Just me, Wire ... On 9/2/06, James Dickens <jamesd.wi at gmail.com> wrote:> On 9/1/06, Tim Cook <tim.cook at qlogic.com> wrote: > > Ok, so here''s my "situation" that I may or may not run into in the future. > > > > Currently I have 3x120GB PATA drives in a RAID-Z as part of my zfs pool. I plan on adding 2x320GB SATA drives in the immediate future to the same pool as a raid-1. Here''s where it gets tricky. In the future, in a perfect world, I''d like to pick up a third 320GB SATA drive to make a RAID-Z out of those as well. So what would be the outcome of the following two scenarios: > > > the best solution is to put the 3rd 320GB drive on a credit card and > get all 3 at once, then you don''t have the headache. > > or wait long enough and they may have the utility to resise raidz > pools. the other option would be if they would implement a 3 disk > raidz pool with one drive degraded. then you could break the mirror, > make the 3 disk raidz pool running in degraded mode. then copy data > over, and then add the 3rd disk to the pool. perhaps that would be a > good RFE "create a raidz with N-1 disks so it runs in degraded mode" > to cope with solutions like these. > > James Dickens > uadmin.blogspot.com > > > > > 1. I have the pool as it stands, but it''s taking up less space than the total free space on the initial PATA RAID-Z. I remove the RAID-1 SATA, make a RAID-Z out of them, and then re-add them to the pool. Can I do this without losing any data? Assuming some is striped across the RAID-1, can it recover gracefully? > > > > 2. I have the pool as it stands, but it''s taking up MORE space than the total free on the initial PATA RAID-Z. I remove the RAID-1 again, to make a RAID-Z. What''s going to happen to that data that is > the RAID-Z can store? Do I lose data? Does it tell me no way, and not allow me to remove the RAID-1 from the pool without a big "idiot you''re about to lose all your data" message? > > > > If there''s anything that doesn''t make sense, please let me know and I''ll try to clarify. > > > > Thanks, > > > > Tim > > > > > > This message posted from opensolaris.org > > _______________________________________________ > > zfs-discuss mailing list > > zfs-discuss at opensolaris.org > > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss > > > _______________________________________________ > zfs-discuss mailing list > zfs-discuss at opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss >