[zfs-discuss] Re: Re: simple Raid-Z question
No one has said that you can't increase the size of a zpool. What can't be increased is the size of a RAID-Z vdev (except by increasing the size of all of the components of the RAID-Z). You have created additional RAID-Z vdevs and added them to the pool. If following is nonsense, please bear with me being a newbie... Suppose you partition the each of the n disk into m equally sized partitions, make m raidz vdevs and finally create one pool from them all. When you then wish to add another disk, you first partition it as the previous ones, then for i in 1:m { remove raidz vdev number i from the pool destroy raidz vdev number i create a raidz vdev from partition i of each of the n+1 disks add the new raidz vdev to the pool } This would demand that 1/m:th of the available disk space would be free, but would make it possible to add additional disks without backup/restore the entire data. Also, it would make it possible to add disks of different sizes, since some raidz:s could include partitions from more disks than others. The interesting question is, what would the performance hit be for pooling m raidz:s from partitions instead of using one regular raidz? Does the driver in some way collect requests for the same disk, which would be destroyed when multiple vdevs in the same pool come from the same disk? Cheers Anders This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Re: Re: simple Raid-Z question
Malachi, The section on adding devices to a ZFS storage pool in the ZFS Admin guide, here, provides an example of adding to a raidz configuration: http://docsview.sfbay/app/docs/doc/817-2271/6mhupg6ft?a=view I think I need to provide a summary of what you can do with both raidz and mirrored configs since you all had trouble finding it. Thanks for the feedback, Cindy Malachi de Ælfweald wrote: Yeah, I am not sure what docs I was originally looking at... Although we may want to ensure that the ZFS Admin Guide is a bit more clear on the matter: Additional disks can be added similarly to a RAID-Z configuration. Malachi On 4/8/07, *Frank Cusack* [EMAIL PROTECTED] mailto:[EMAIL PROTECTED] wrote: [top-posting corrected] On April 8, 2007 1:43:48 PM -0700 Malachi de Ælfweald [EMAIL PROTECTED] mailto:[EMAIL PROTECTED] wrote: On 4/7/07, Eric Haycraft [EMAIL PROTECTED] mailto:[EMAIL PROTECTED] wrote: You cannot add 1 drive at a time to a raid-z or raid-2z. You need to add the same number of disks that were used per stripe.. So, if you start with 5 disks, you would have to add 5 more in the future to add disk space. There is also a method of swapping each disk one at a time with a larger disk and performing a scrub inbetween each replacement to increase the pool size. Hmmm... I definitely missed this one... I thought the documentation said that using zpool attach would add a new drive to the existing raidz(2) and then it would start resilvering... zpool(1M): zpool attach [-f] pool device new_device Attaches new_device to an existing zpool device. The existing device cannot be part of a raidz configuration. -frank ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Re: Re: simple Raid-Z question
Here's the correct link: http://docs.sun.com/app/docs/doc/817-2271/6mhupg6ft?a=view The same example exists on page 52 of the 817-2271 PDF posted on the opensolaris.../zfs/documentation page. Cindy Malachi de Ælfweald wrote: FYI That page is not publicly viewable. It was the 817-2271 pdf I was looking at though. Malachi On 4/9/07, * [EMAIL PROTECTED] mailto:[EMAIL PROTECTED]* [EMAIL PROTECTED] mailto:[EMAIL PROTECTED] wrote: Malachi, The section on adding devices to a ZFS storage pool in the ZFS Admin guide, here, provides an example of adding to a raidz configuration: http://docsview.sfbay/app/docs/doc/817-2271/6mhupg6ft?a=view I think I need to provide a summary of what you can do with both raidz and mirrored configs since you all had trouble finding it. Thanks for the feedback, Cindy Malachi de Ælfweald wrote: Yeah, I am not sure what docs I was originally looking at... Although we may want to ensure that the ZFS Admin Guide is a bit more clear on the matter: Additional disks can be added similarly to a RAID-Z configuration. Malachi On 4/8/07, *Frank Cusack* [EMAIL PROTECTED] mailto:[EMAIL PROTECTED] mailto: [EMAIL PROTECTED] mailto:[EMAIL PROTECTED] wrote: [top-posting corrected] On April 8, 2007 1:43:48 PM -0700 Malachi de Ælfweald [EMAIL PROTECTED] mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] wrote: On 4/7/07, Eric Haycraft [EMAIL PROTECTED] mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] wrote: You cannot add 1 drive at a time to a raid-z or raid-2z. You need to add the same number of disks that were used per stripe.. So, if you start with 5 disks, you would have to add 5 more in the future to add disk space. There is also a method of swapping each disk one at a time with a larger disk and performing a scrub inbetween each replacement to increase the pool size. Hmmm... I definitely missed this one... I thought the documentation said that using zpool attach would add a new drive to the existing raidz(2) and then it would start resilvering... zpool(1M): zpool attach [-f] pool device new_device Attaches new_device to an existing zpool device. The existing device cannot be part of a raidz configuration. -frank ___ zfs-discuss mailing list zfs-discuss@opensolaris.org mailto:zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss ___ zfs-discuss mailing list zfs-discuss@opensolaris.org mailto:zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
[zfs-discuss] Re: Re: simple Raid-Z question
You cannot add 1 drive at a time to a raid-z or raid-2z. You need to add the same number of disks that were used per stripe.. So, if you start with 5 disks, you would have to add 5 more in the future to add disk space. There is also a method of swapping each disk one at a time with a larger disk and performing a scrub inbetween each replacement to increase the pool size. Eric This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
[zfs-discuss] Re: Re: simple Raid-Z question
One option is you can replace all the existing devices in a raidz vdev with larger devices, and then export/import the pool and the vdev will grow in size. I agree that you simply can't add a single device to grow a raidz vdev. This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Re: Re: simple Raid-Z question
On April 7, 2007 11:11:37 PM -0700 Eric Haycraft [EMAIL PROTECTED] wrote: You cannot add 1 drive at a time to a raid-z or raid-2z. You need to add the same number of disks that were used per stripe. You cannot add drives to a raid-z or raid-z2, period. -frank ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Re: Re: simple Raid-Z question
Hmmm... I definitely missed this one... I thought the documentation said that using zpool attach would add a new drive to the existing raidz(2) and then it would start resilvering... Malachi On 4/7/07, Eric Haycraft [EMAIL PROTECTED] wrote: You cannot add 1 drive at a time to a raid-z or raid-2z. You need to add the same number of disks that were used per stripe.. So, if you start with 5 disks, you would have to add 5 more in the future to add disk space. There is also a method of swapping each disk one at a time with a larger disk and performing a scrub inbetween each replacement to increase the pool size. Eric This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Re: Re: simple Raid-Z question
[top-posting corrected] On April 8, 2007 1:43:48 PM -0700 Malachi de Ælfweald [EMAIL PROTECTED] wrote: On 4/7/07, Eric Haycraft [EMAIL PROTECTED] wrote: You cannot add 1 drive at a time to a raid-z or raid-2z. You need to add the same number of disks that were used per stripe.. So, if you start with 5 disks, you would have to add 5 more in the future to add disk space. There is also a method of swapping each disk one at a time with a larger disk and performing a scrub inbetween each replacement to increase the pool size. Hmmm... I definitely missed this one... I thought the documentation said that using zpool attach would add a new drive to the existing raidz(2) and then it would start resilvering... zpool(1M): zpool attach [-f] pool device new_device Attaches new_device to an existing zpool device. The existing device cannot be part of a raidz configuration. -frank ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Re: Re: simple Raid-Z question
Yeah, I am not sure what docs I was originally looking at... Although we may want to ensure that the ZFS Admin Guide is a bit more clear on the matter: Additional disks can be added similarly to a RAID-Z configuration. Malachi On 4/8/07, Frank Cusack [EMAIL PROTECTED] wrote: [top-posting corrected] On April 8, 2007 1:43:48 PM -0700 Malachi de Ælfweald [EMAIL PROTECTED] wrote: On 4/7/07, Eric Haycraft [EMAIL PROTECTED] wrote: You cannot add 1 drive at a time to a raid-z or raid-2z. You need to add the same number of disks that were used per stripe.. So, if you start with 5 disks, you would have to add 5 more in the future to add disk space. There is also a method of swapping each disk one at a time with a larger disk and performing a scrub inbetween each replacement to increase the pool size. Hmmm... I definitely missed this one... I thought the documentation said that using zpool attach would add a new drive to the existing raidz(2) and then it would start resilvering... zpool(1M): zpool attach [-f] pool device new_device Attaches new_device to an existing zpool device. The existing device cannot be part of a raidz configuration. -frank ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Re: Re: simple Raid-Z question
Malachi de Ælfweald wrote: Hmmm... I definitely missed this one... I thought the documentation said that using zpool attach would add a new drive to the existing raidz(2) and then it would start resilvering... Malachi The man page is a little unclear. zpool attach is for adding drives to a mirror vdev (or, creating a mirrored vdev from a single drive). It is NOT for use with RAIDZ or RAIDZ2 vdevs (hopefully, in the future...) Also, to be even more clear, the only way to add devices to a zpool with RAIDZ/RAIDZ2 is to add another stripe. Which really isn't adding anything to the RAIDZ vdev. That is, if you have a zpool consisting of a 4-drive RAIDZ, as in: zpool create tank raidz c1t0d0 c1t1d0 c1t2d0 c1t3d0 you can only expand it by adding sufficient disk to create a whole new stripe - so, effectively, your data will be striped between the existing RAIDZ vdev, and the one you add. i.e. zpool add tank raidz c2t0d0 c2t1d0 c2t2d0 c2t3d0 So, if you started out with 4 100GB drives in the above config, you'd have 300GB usable. You'd then have to add 4 more 100GB drives, and the final zpool size would be 600GB, with data in striped across 2 4-drive RAIDZ vdevs. What most people here would prefer is that you could instead (if desired) end up with a single RAIDZ2 vdev of 6 data drives and 2 parity drives, but that is NOT currently possible. -- Erik Trimble Java System Support Mailstop: usca22-123 Phone: x17195 Santa Clara, CA Timezone: US/Pacific (GMT-0800) ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Re: Re: simple Raid-Z question
Yeah, what I had been hoping (and to be honest kinda counting on) was that I could do a raidz2 across the 7x250GB drives (which is not actually going to happen since I am going to mirror 2 of them for boot) and then just add another 250GB drive when more space is needed. Realistically, I am not going to need that functionality right away, but have to admit it was one of the reasons I have been touting ZFS to everyone. Malachi On 4/8/07, Erik Trimble [EMAIL PROTECTED] wrote: Malachi de Ælfweald wrote: Hmmm... I definitely missed this one... I thought the documentation said that using zpool attach would add a new drive to the existing raidz(2) and then it would start resilvering... Malachi The man page is a little unclear. zpool attach is for adding drives to a mirror vdev (or, creating a mirrored vdev from a single drive). It is NOT for use with RAIDZ or RAIDZ2 vdevs (hopefully, in the future...) Also, to be even more clear, the only way to add devices to a zpool with RAIDZ/RAIDZ2 is to add another stripe. Which really isn't adding anything to the RAIDZ vdev. That is, if you have a zpool consisting of a 4-drive RAIDZ, as in: zpool create tank raidz c1t0d0 c1t1d0 c1t2d0 c1t3d0 you can only expand it by adding sufficient disk to create a whole new stripe - so, effectively, your data will be striped between the existing RAIDZ vdev, and the one you add. i.e. zpool add tank raidz c2t0d0 c2t1d0 c2t2d0 c2t3d0 So, if you started out with 4 100GB drives in the above config, you'd have 300GB usable. You'd then have to add 4 more 100GB drives, and the final zpool size would be 600GB, with data in striped across 2 4-drive RAIDZ vdevs. What most people here would prefer is that you could instead (if desired) end up with a single RAIDZ2 vdev of 6 data drives and 2 parity drives, but that is NOT currently possible. -- Erik Trimble Java System Support Mailstop: usca22-123 Phone: x17195 Santa Clara, CA Timezone: US/Pacific (GMT-0800) ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
[zfs-discuss] Re: Re: simple Raid-Z question
Since no one seems to believe that you can expand a raidz pool, I have attached the following output from solaris 11/06 showing me doing just that. The first expanision is with like sized disks, and the second expansion is with larger disks. I realize that the documentation only has examples using mirrors, but raidz and raid2z are fully supported for adding disk space. # mkfile 64m 1 2 3 4 5 6 # mkfile 128m 01 02 03 # zpool create testpool raidz `pwd`/1 `pwd`/2 `pwd`/3 # zpool list testpool NAMESIZEUSED AVAILCAP HEALTH ALTROOT testpool178M100K178M 0% ONLINE - # zpool add testpool raidz `pwd`/4 `pwd`/5 `pwd`/6 # zpool list testpool NAMESIZEUSED AVAILCAP HEALTH ALTROOT testpool356M305K356M 0% ONLINE - # zpool add testpool raidz `pwd`/01 `pwd`/02 `pwd`/03 # zpool list testpool NAMESIZEUSED AVAILCAP HEALTH ALTROOT testpool726M475K726M 0% ONLINE - # This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Re: Re: simple Raid-Z question
Eric Haycraft wrote: Since no one seems to believe that you can expand a raidz pool, I have attached the following output from solaris 11/06 showing me doing just that. The first expanision is with like sized disks, and the second expansion is with larger disks. I realize that the documentation only has examples using mirrors, but raidz and raid2z are fully supported for adding disk space. No one has said that you can't increase the size of a zpool. What can't be increased is the size of a RAID-Z vdev (except by increasing the size of all of the components of the RAID-Z). You have created additional RAID-Z vdevs and added them to the pool. -- --Ed ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss