[zfs-discuss] Host based zfs config with Oracle's Unified Storage 7000 series
My question regarding the 7000 series storage is in more of the perspective of the HOST side ZFS config. It is my understanding that the 7000 storage displays a FC lun to the host. Yes, this LUN is a ZFS lun in the 7000 storage, however the host still sees this as only one LUN. If I configure a host based ZFS storage device on top of this LUN I have no host based zfs redundancy. So do we still need to create a host based ZFS mirror or a host based ZFS raidz device when use a 7000 series storage array? Thanks, Shawn -- This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
[zfs-discuss] ZFS znapshot of zone that contains ufs SAN attached file systems
Hi All, If a zone root is on zfs but that zone also contains SAN attached UFS devices what is recorded in a zfs snapshot of the zone? Does the snapshot only contain the ZFS root info? How would one recover this complete zone? Thanks, Shawn -- 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] Does ZFS work with SAN-attached devices?
Prior to this fix ZFS would panic the systems in order to avoid data corruption and loss of the zpool. Now the pool goes into a degraded or faulted state and one can "try" the zpool clear command to correct the issue. If this does not succeed a reboot is required. -- 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] Does ZFS work with SAN-attached devices?
Just to put closure to this discussion about how CR 6565042 and 6322646 change how ZFS functions with in the below scenario. >ZFS no longer has the issue where loss of a single device (even >intermittently) causes pool corruption. That's been fixed. > >That is, there used to be an issue in this scenario: > >(1) zpool constructed from a single LUN on a SAN device >(2) SAN experiences temporary outage, while ZFS host remains running. >(3) zpool is permanently corrupted, even if no I/O occured during outage > >This is fixed. (around b101, IIRC) > >I went back and dug through some of my email, and the issue showed up as >CR 6565042. > >That was fixed in b77 and s10 update 6." After doing further research, and speaking with the CR engineers, the CR changes seem to be included in an overall fix for ZFS panic situations. The Zpool can still go into a degraded or faulted state, which will require manual intervention by the user. This fix was discussed above in information from infodoc 211349 Solaris[TM] ZFS & Write Failure "ZFS will handle the drive failures gracefully as part of the BUG 6322646 fix in the case of non-redundant configurations by degrading the pool instead of initiating a system panic with the help of Solaris[TM] FMA framework." -- 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] Does ZFS work with SAN-attached devices?
>In life there are many things that we "should do" (but often don't). >There are always trade-offs. If you need your pool to be able to >operate with a device missing, then the pool needs to have sufficient >redundancy to keep working. If you want your pool to survive if a >disk gets crushed by a wayward fork lift, then you need to have >redundant storage so that the data continues to be available. > >If the devices are on a SAN and you want to be able to continue >operating while there is a SAN failure, then you need to have >redundant SAN switches, redundant paths, and redundant storage >devices, preferably in a different chassis. Yes, of course. This is part of normal SAN design. The ZFS file systems is what is different here. If a either a HBA, fibre cable, redundant controller fail or firmware issues on a array redundant controller occur then SSTM (MPXIO) will see the issue and try and fail things over to the other controller. Of course this reaction at the SSTM level takes time. UFS simply allows this to happen. It is my understanding ZFS can have issues with this hence the reason why a zfs mirror or raidz device is required. Still not clear how the above mentioned BUGS change the behavior of zfs and if they change the recommendations of the zpool man page. > >Bob >-- >Bob Friesenhahn >bfriesen at simple dot dallas dot tx dot us, >http://www.simplesystems.org/users/bfriesen/ >GraphicsMagick Maintainer, http://www.GraphicsMagick.org/ ___ -- 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] Does ZFS work with SAN-attached devices?
>I went back and dug through some of my email, and the issue showed up as >CR 6565042. > >That was fixed in b77 and s10 update 6. > >I looked at this CR, forgive me but I am not a ZFS engineer. Can you explain >in, >simple terms, how ZFS now reacts to this? If it does not panic how does >it insure >data is save? Found some conflicting information Infodoc: 211349 Solaris[TM] ZFS & Write Failure. "ZFS will handle the drive failures gracefully as part of the BUG 6322646 fix in the case of non-redundant configurations by degrading the pool instead of initiating a system panic with the help of Solaris[TM] FMA framework." >From Richards post above. "NB definitions of the pool states, including "degraded" are in the zpool(1m) man page. -- richard" >From zpool man page located below. http://docs.sun.com/app/docs/doc/819-2240/zpool-1m?l=en&a=view&q=zpool "Device Failure and Recovery ZFS supports a rich set of mechanisms for handling device failure and data corruption. All metadata and data is checksummed, and ZFS automatically repairs bad data from a good copy when corruption is detected. In order to take advantage of these features, a pool must make use of some form of redundancy, using either mirrored or raidz groups. While ZFS supports running in a non-redundant configuration, where each root vdev is simply a disk or file, this is strongly discouraged. A single case of bit corruption can render some or all of your data unavailable. A pool's health status is described by one of three states: online, degraded, or faulted. An online pool has all devices operating normally. A degraded pool is one in which one or more devices have failed, but the data is still available due to a redundant configuration. A faulted pool has corrupted metadata, or one or more faulted devices, and insufficient replicas to continue functioning. The health of the top-level vdev, such as mirror or raidz device, is potentially impacted by the state of its associated vdevs, or component devices. A top-level vdev or component device is in one of the following states:" So from the zpool man page it seems that it is not possible to put a single device zpool in a degraded state. Is this correct or does the fix in Bugs 6565042 and 6322646 change this behavior. > >Also, just want to ensure everyone is on the same page here. There seems to be >>some mixed messages in this thread about how sensitive ZFS is to SAN issues. > >Do we all agree that creating a zpool out of one device in a SAN environment >is >not recommended. One should always constructs a zfs mirror or raidz device >out >of SAN attached devices, as posted in the ZFS FAQ? The zpool man page seem to agree with this. Is this correct? -- 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] Does ZFS work with SAN-attached devices?
>I went back and dug through some of my email, and the issue showed up as >CR 6565042. > >That was fixed in b77 and s10 update 6. I looked at this CR, forgive me but I am not a ZFS engineer. Can you explain in, simple terms, how ZFS now reacts to this? If it does not panic how does it insure data is save? Also, just want to ensure everyone is on the same page here. There seems to be some mixed messages in this thread about how sensitive ZFS is to SAN issues. Do we all agree that creating a zpool out of one device in a SAN environment is not recommended. One should always constructs a zfs mirror or raidz device out of SAN attached devices, as posted in the ZFS FAQ? -- 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] Does ZFS work with SAN-attached devices?
>If you don't give ZFS any redundancy, you risk loosing you pool if there is data corruption. Is this the same risk for data corruption as UFS on hardware based luns? If we present one LUN to ZFS and choose not to ZFS mirror or do a raidz pool of that LUN is ZFS able to handle disk or raid controllers failures on the hardware array? Does ZFS handle intermittent controller outages on the raid controllers the same as what UFS would? Thanks, Shawn Ian Collins wrote: Shawn Joy wrote: Hi All, Its been a while since I touched zfs. Is the below still the case with zfs and hardware raid array? Do we still need to provide two luns from the hardware raid then zfs mirror those two luns? http://www.opensolaris.org/os/community/zfs/faq/#hardwareraid Need, no. Should, yes. The last two points on that page are key: "Overall, ZFS functions as designed with SAN-attached devices, but if you expose simpler devices to ZFS, you can better leverage all available features. In summary, if you use ZFS with SAN-attached devices, you can take advantage of the self-healing features of ZFS by configuring redundancy in your ZFS storage pools even though redundancy is available at a lower hardware level." If you don't give ZFS any redundancy, you risk loosing you pool if there is data corruption. ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Does ZFS work with SAN-attached devices?
>If you don't give ZFS any redundancy, you risk loosing you pool if there is >data corruption. Is this the same risk for data corruption as UFS on hardware based luns? If we present one LUN to ZFS and choose not to ZFS mirror or do a raidz pool of that LUN is ZFS able to handle disk or raid controllers failures on the hardware array? Does ZFS handle intermittent controller outages on the raid controllers the same as what UFS would? Thanks, Shawn -- This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
[zfs-discuss] Does ZFS work with SAN-attached devices?
Hi All, Its been a while since I touched zfs. Is the below still the case with zfs and hardware raid array? Do we still need to provide two luns from the hardware raid then zfs mirror those two luns? http://www.opensolaris.org/os/community/zfs/faq/#hardwareraid Thanks, Shawn -- 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] "Poor Man's Cluster" using zpool export and zpool import
Thanks Cindy and Darren -- This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
[zfs-discuss] "Poor Man's Cluster" using zpool export and zpool import
Is it supported to use zpool export and zpool import to manage disk access between two nodes that have access to the same storage device. What issues exist if the host currently owning the zpool goes down? In this case will using zpool import -f work? Is there possible data corruption issues? Thanks, Shawn -- This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
[zfs-discuss] ZFS boot and data on same disk - is this supported?
I have read the ZFS best practice guide located at http://www.solarisinternals.com/wiki/index.php/ZFS_Best_Practices_Guide However I have questions whether we support using slices for data on the same disk as we use for ZFS boot. What issues does this create if we have a disk failure in a mirrored environment? Does anyone have examples of customers doing this in production environments. I have a customer looking to use ZFS boot but they only have two disks in their server and it is not connected to a SAN. They also need space for data what is he best recommendation? Please respond to me directly as I am not on this alias. Shawn ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] zfs boot Solaris 10/08 whole disk or slice
If one chooses to do this what happens if you have a disk failure. >From the ZFS Best practices guide. The recovery process of replacing a failed disk is more complex when disks contain both ZFS and UFS file systems on slices. Shawn -- This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
[zfs-discuss] zfs boot Solaris 10/08 whole disk or slice
Hi All, I see from the zfs Best practices guide http://www.solarisinternals.com/wiki/index.php/ZFS_Best_Practices_Guide ZFS Root Pool Considerations * A root pool must be created with disk slices rather than whole disks. Allocate the entire disk capacity for the root pool to slice 0, for example, rather than partition the disk that is used for booting for many different uses. What issues are there if one would like to uses other slices on the same disk for data. Is this even supported in Solaris 10/08? -- 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] mirror a slice
What are the commands? Everything I see is c1t0d0, c1t1d0. no slice just the completed disk. Robert Milkowski wrote: > Hello Shawn, > > Thursday, December 13, 2007, 3:46:09 PM, you wrote: > > SJ> Is it possible to bring one slice of a disk under zfs controller and > SJ> leave the others as ufs? > > SJ> A customer is tryng to mirror one slice using zfs. > > > Yes, it's - it just works. > > ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
[zfs-discuss] mirror a slice
Is it possible to bring one slice of a disk under zfs controller and leave the others as ufs? A customer is tryng to mirror one slice using zfs. Please respond to me directly and to the alias. Thanks, Shawn ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Re: Difference between ZFS and UFS with one LUN froma SAN
No, I have not played with this. As I do not have access to my customer site. They have tested this themselves. It is unclear if they implemented this on a MPXIO/SSTM device. I will ask this question. Thanks, Shawn Tim Cook wrote: This may not be the answer you're looking for, but I don't know if it's something you've thought of. If you're pulling a LUN from an expensive array, with multiple HBA's in the system, why not run mpxio? If you ARE running mpxio, there shouldn't be an issue with a path dropping. I have the setup above in my test lab and pull cables all the time and have yet to see a zfs kernel panic. Is this something you've considered? I haven't seen the bug in question, but I definitely have not run into it when running mpxio. --Tim -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Shawn Joy Sent: Friday, December 22, 2006 7:35 AM To: zfs-discuss@opensolaris.org Subject: [zfs-discuss] Re: Difference between ZFS and UFS with one LUN froma SAN OK, But lets get back to the original question. Does ZFS provide you with less features than UFS does on one LUN from a SAN (i.e is it less stable). ZFS on the contrary checks every block it reads and is able to find the mirror or reconstruct the data in a raidz config. Therefore ZFS uses only valid data and is able to repair the data blocks automatically. This is not possible in a traditional filesystem/volume manager configuration. The above is fine. If I have two LUNs. But my original question was if I only have one LUN. What about kernel panics from ZFS if for instance access to one controller goes away for a few seconds or minutes. Normally UFS would just sit there and warn I have lost access to the controller. Then when the controller returns, after a short period, the warnings go away and the LUN continues to operate. The admin can then research further into why the controller went away. With ZFS, the above will panic the system and possibly cause other coruption on other LUNs due to this panic? I believe this was discussed in other threads? I also believe there is a bug filed against this? If so when should we expect this bug to be fixed? My understanding of ZFS is that it functions better in an environment where we have JBODs attached to the hosts. This way ZFS takes care of all of the redundancy? But what about SAN enviroments where customers have spend big money to invest in storage. I know of one instance where a customer has a growing need for more storage space. There environemt uses many inodes. Due to the UFS inode limitation, when creating LUNs over one TB, they would have to quadrulpe the about of storage usesd in there SAN in order to hold all of the files. A possible solution to this inode issue would be ZFS. However they have experienced kernel panics in there environment when a controller dropped of line. Any body have a solution to this? Shawn This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss -- Shawn Joy Systems Support Specialist Sun Microsystems, Inc. 1550 Bedford Highway, Suite 302 Bedford, Nova Scotia B4A 1E6 CA Phone 902-832-6213 Fax 902-835-6321 Email [EMAIL PROTECTED] ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
[zfs-discuss] Re: Difference between ZFS and UFS with one LUN from a SAN
OK, But lets get back to the original question. Does ZFS provide you with less features than UFS does on one LUN from a SAN (i.e is it less stable). >ZFS on the contrary checks every block it reads and is able to find the >mirror >or reconstruct the data in a raidz config. >Therefore ZFS uses only valid data and is able to repair the data blocks >automatically. >This is not possible in a traditional filesystem/volume manager >configuration. The above is fine. If I have two LUNs. But my original question was if I only have one LUN. What about kernel panics from ZFS if for instance access to one controller goes away for a few seconds or minutes. Normally UFS would just sit there and warn I have lost access to the controller. Then when the controller returns, after a short period, the warnings go away and the LUN continues to operate. The admin can then research further into why the controller went away. With ZFS, the above will panic the system and possibly cause other coruption on other LUNs due to this panic? I believe this was discussed in other threads? I also believe there is a bug filed against this? If so when should we expect this bug to be fixed? My understanding of ZFS is that it functions better in an environment where we have JBODs attached to the hosts. This way ZFS takes care of all of the redundancy? But what about SAN enviroments where customers have spend big money to invest in storage. I know of one instance where a customer has a growing need for more storage space. There environemt uses many inodes. Due to the UFS inode limitation, when creating LUNs over one TB, they would have to quadrulpe the about of storage usesd in there SAN in order to hold all of the files. A possible solution to this inode issue would be ZFS. However they have experienced kernel panics in there environment when a controller dropped of line. Any body have a solution to this? Shawn This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
[zfs-discuss] Difference between ZFS and UFS with one LUN from a SAN
All, I understand that ZFS gives you more error correction when using two LUNS from a SAN. But, does it provide you with less features than UFS does on one LUN from a SAN (i.e is it less stable). Thanks, Shawn This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
