Re: [zfs-discuss] [storage-discuss] OpenSolaris ZFS NAS Setup
Jonathan Loran wrote: > Vincent Fox wrote: > >> Followup, my initiator did eventually panic. >> >> I will have to do some setup to get a ZVOL from another system to mirror >> with, and see what happens when one of them goes away. Will post in a day >> or two on that. >> >> >> > On Sol 10 U4, I could have told you that. A few weeks back, I was bone > headed, and took down a target with a completely idle zpool on it. The > initiator system eventually panicked, when I brought the target back > up! But this pool wasn't mirrored. I'm hoping I can setup a mirror of > iSCSI targets and get all the benefits of HA. > This is the expected behaviour for an unprotected Solaris 10 u4 setup. -- richard ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] [storage-discuss] OpenSolaris ZFS NAS Setup
Vincent Fox wrote: > Followup, my initiator did eventually panic. > > I will have to do some setup to get a ZVOL from another system to mirror > with, and see what happens when one of them goes away. Will post in a day or > two on that. > > On Sol 10 U4, I could have told you that. A few weeks back, I was bone headed, and took down a target with a completely idle zpool on it. The initiator system eventually panicked, when I brought the target back up! But this pool wasn't mirrored. I'm hoping I can setup a mirror of iSCSI targets and get all the benefits of HA. BTW Vincent: thanks for doing all my testing for me ;) Seriously, I'm throwing together a test setup of my own on Monday. Need to be sure this will work. Jon ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] [storage-discuss] OpenSolaris ZFS NAS Setup
kristof wrote: > If you have a mirrored iscsi zpool. It will NOT panic when 1 of the > submirrors is unavailable. > > zpool status will hang for some time, but after I thinkt 300 seconds it will > put the device on unavailable. > > The panic was the default in the past, And it only occurs if all devices are > unavailable. > > Since I think b77 there is a new zpool property: failemode, which you can set > to prevent a panic: > > failmode=wait | continue | panic > > Controls the system behavior in the event of catas- > trophic pool failure. This condition is typically a > result of a loss of connectivity to the underlying > storage device(s) or a failure of all devices within the > pool. The behavior of such an event is determined as > follows: > > waitBlocks all I/O access until the device con- > nectivity is recovered and the errors are > cleared. This is the default behavior. > > continueReturns EIO to any new write I/O requests > but allows reads to any of the remaining > healthy devices. Any write requests that > have yet to be committed to disk would be > blocked. > > panic Prints out a message to the console and gen- > erates a system crash dump. > > > This is encouraging, but one problem: Our system is on Solaris 10 U4. Will this guy be immune to panics when one side of the mirror goes down? Seriously, I'm tempted to upgrade this box to OS b8? However, there are a lot of dependencies which we need to worry about in doing that - for example, will all our off the shelf software run with Open Solaris. More things to test. Thanks, Jon ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] [storage-discuss] OpenSolaris ZFS NAS Setup
Followup, my initiator did eventually panic. I will have to do some setup to get a ZVOL from another system to mirror with, and see what happens when one of them goes away. Will post in a day or two on that. 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] [storage-discuss] OpenSolaris ZFS NAS Setup
Followup, my initiator did eventually panic. I will have to do some setup to get a ZVOL from another system to mirror with, and see what happens when one of them goes away. Will post in a day or two on that. 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] [storage-discuss] OpenSolaris ZFS NAS Setup
I don't think ANY situation in which you are mirrored and one half of the mirror pair becomes unavailable will panic the system. At least this has been the case when I've tested with local storage haven't tried with iSCSI yet but will give it a whirl. I had a simple single ZVOL shared over iSCSI, and thus no redundancy. And bringing down the target system didn't crash the initiator. And this is with Solaris 10u4 not even latest OpenSolaris. Well okay if I'm logged onto the initator and in the directory for the pool at the time I bring down the target, my shell gets hung. But it hasn't panicked I will wait a good 15 minutes and make sure of this and post some failure-mode results later this evening. 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] [storage-discuss] OpenSolaris ZFS NAS Setup
If you have a mirrored iscsi zpool. It will NOT panic when 1 of the submirrors is unavailable. zpool status will hang for some time, but after I thinkt 300 seconds it will put the device on unavailable. The panic was the default in the past, And it only occurs if all devices are unavailable. Since I think b77 there is a new zpool property: failemode, which you can set to prevent a panic: failmode=wait | continue | panic Controls the system behavior in the event of catas- trophic pool failure. This condition is typically a result of a loss of connectivity to the underlying storage device(s) or a failure of all devices within the pool. The behavior of such an event is determined as follows: waitBlocks all I/O access until the device con- nectivity is recovered and the errors are cleared. This is the default behavior. continueReturns EIO to any new write I/O requests but allows reads to any of the remaining healthy devices. Any write requests that have yet to be committed to disk would be blocked. panic Prints out a message to the console and gen- erates a system crash dump. 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] [storage-discuss] OpenSolaris ZFS NAS Setup
On Sat, Apr 5, 2008 at 5:25 AM, Jonathan Loran <[EMAIL PROTECTED]> wrote: > This is scaring the heck out of me. I have a project to create a zpool > mirror out of two iSCSI targets, and if the failure of one of them will > panic my system, that will be totally unacceptable. I haven't tried this myself, but perhaps the "failmode" property of zfs will solve this? Will ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
