Re: [zfs-discuss] (Fletcher+Verification) versus (Sha256+No Verification)
On 01/ 7/11 09:02 PM, Pawel Jakub Dawidek wrote: On Fri, Jan 07, 2011 at 07:33:53PM +, Robert Milkowski wrote: Now what if block B is a meta-data block? Metadata is not deduplicated. Good point but then it depends on a perspective. What if you you are storing lots of VMDKs? One corrupted block which is shared among hundreds of VMDKs will affect all of them. And it might be a block containing meta-data information within vmdk... Anyway, green or not, imho if in a given environment turning verification on still delivers acceptable performance then I would basically turn it on. In other environments it is about risk assessment. Best regards, Robert Milkowski ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] A few questions
On 01/ 6/11 05:28 AM, Edward Ned Harvey wrote: From: Khushil Dep [mailto:khushil@gmail.com] I've deployed large SAN's on both SuperMicro 825/826/846 and Dell R610/R710's and I've not found any issues so far. I always make a point of installing Intel chipset NIC's on the DELL's and disabling the Broadcom ones but other than that it's always been plain sailing - hardware-wise anyway. not found any issues, except the broadcom one which causes the system to crash regularly in the default factory configuration. How did you learn about the broadcom issue for the first time? I had to learn the hard way, and with all the involvement of both Dell and Oracle support teams, nobody could tell me what I needed to change. We literally replaced every component of the server twice over a period of 1 year, and I spent mandays upgrading and downgrading firmwares randomly trying to find a stable configuration. I scoured the internet to find this little tidbit about replacing the broadcom NIC, and randomly guessed, and replaced my nic with an intel card to make the problem go away. The same system doesn't have a problem running RHEL/centos. What will be the new problem in the next line of servers? Why, during my internet scouring, did I find a lot of other reports, of people who needed to disable c-states (didn't work for me) and lots of false leads indicating firmware downgrade would fix my broadcom issue? See my point? Next time I buy a server, I do not have confidence to simply expect solaris on dell to work reliably. The same goes for solaris derivatives, and all non-sun hardware. There simply is not an adequate qualification and/or support process. When you purchase NexentaStor from a top-tier Nexenta Hardware Partner, you get a product that has been through a rigorous qualification process which includes the hardware and software configuration matched together, tested with an extensive battery. You also can get a higher level of support than is offered to people who build their own systems. Oracle is *not* the only company capable of performing in depth testing of Solaris. I can also know enough about problems that Oracle customers (or rather Sun customers) faced with Solaris on Sun hardware -- such as the terrible nvidia ethernet problems on first generation U20 and U40 problems, or the marvell SATA problems on Thumper -- that I know that your picture of Oracle isn't nearly as rosy as you believe. Of course, I also lived (as a Sun employee) through the UltraSPARC-II ECC fiasco... - Garrett ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] A few questions
On Thu, Jan 6, 2011 at 11:36 PM, Garrett D'Amore garr...@nexenta.com wrote: On 01/ 6/11 05:28 AM, Edward Ned Harvey wrote: See my point? Next time I buy a server, I do not have confidence to simply expect solaris on dell to work reliably. The same goes for solaris derivatives, and all non-sun hardware. There simply is not an adequate qualification and/or support process. When you purchase NexentaStor from a top-tier Nexenta Hardware Partner, you Where is the list? Is this the one on http://www.nexenta.com/corp/technology-partners-overview/certified-technology-partners ? get a product that has been through a rigorous qualification process which includes the hardware and software configuration matched together, tested with an extensive battery. You also can get a higher level of support than is offered to people who build their own systems. Oracle is *not* the only company capable of performing in depth testing of Solaris. Does this roughly mean I can expect similar (or even better) hardware compatibility support and with nexentastor on supermicro as solaris on oracle/sun hardware? -- Fajar ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] A few questions
From: zfs-discuss-boun...@opensolaris.org [mailto:zfs-discuss- boun...@opensolaris.org] On Behalf Of Garrett D'Amore When you purchase NexentaStor from a top-tier Nexenta Hardware Partner, you get a product that has been through a rigorous qualification process How do I do this, exactly? I am serious. Before too long, I'm going to need another server, and I would very seriously consider reprovisioning my unstable Dell Solaris server to become a linux or some other stable machine. The role it's currently fulfilling is the backup server, which basically does nothing except zfs receive from the primary Sun solaris 10u9 file server. Since the role is just for backups, it's a perfect opportunity for experimentation, hence the Dell hardware with solaris. I'd be happy to put some other configuration in there experimentally instead ... say ... nexenta. Assuming it will be just as good at zfs receive from the primary server. Is there some specific hardware configuration you guys sell? Or recommend? How about a Dell R510/R610/R710? Buy the hardware separately and buy NexentaStor as just a software product? Or buy a somehow more certified hardware software bundle together? If I do encounter a bug, where the only known fact is that the system keeps crashing intermittently on an approximately weekly basis, and there is absolutely no clue what's wrong in hardware or software... How do you guys handle it? If you'd like to follow up offlist, that's fine. Then just email me at the email address: nexenta at nedharvey.com (I use disposable email addresses on mailing lists like this, so at any random unknown time, I'll destroy my present alias and start using a new one.) ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] (Fletcher+Verification) versus (Sha256+No Verification)
From: zfs-discuss-boun...@opensolaris.org [mailto:zfs-discuss- boun...@opensolaris.org] On Behalf Of Robert Milkowski What if you you are storing lots of VMDKs? One corrupted block which is shared among hundreds of VMDKs will affect all of them. And it might be a block containing meta-data information within vmdk... Although the probability of hash collision is astronomically infinitesimally small, if it were to happen, the damage could be expansive and unrecoverable. Even backups could not protect you, because the corruption would be replicated undetected into your backups too. Just like other astronomical events (meteors, supernova, etc) which could destroy all your data, all your backups, and kill everyone you know, if these risks are not acceptable to you, you need to take precautions against it. But you have to weigh the odds of damage versus the cost of protection. Admittedly, precautions against nuclear strike are more costly to implement than precaution against hash collision (enabling verification is a trivial task). But that does not mean enabling verification comes without cost. Has anybody measured the cost of enabling or disabling verification? The cost of disabling verification is an infinitesimally small number multiplied by possibly all your data. Basically lim-0 times lim-infinity. This can only be evaluated on a case-by-case basis and there's no use in making any more generalizations in favor or against it. The benefit of disabling verification would presumably be faster performance. Has anybody got any measurements, or even calculations or vague estimates or clueless guesses, to indicate how significant this is? How much is there to gain by disabling verification? ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] A few questions
Am 08.01.11 18:33, schrieb Edward Ned Harvey: From: zfs-discuss-boun...@opensolaris.org [mailto:zfs-discuss- boun...@opensolaris.org] On Behalf Of Garrett D'Amore When you purchase NexentaStor from a top-tier Nexenta Hardware Partner, you get a product that has been through a rigorous qualification process How do I do this, exactly? I am serious. Before too long, I'm going to need another server, and I would very seriously consider reprovisioning my unstable Dell Solaris server to become a linux or some other stable machine. The role it's currently fulfilling is the backup server, which basically does nothing except zfs receive from the primary Sun solaris 10u9 file server. Since the role is just for backups, it's a perfect opportunity for experimentation, hence the Dell hardware with solaris. I'd be happy to put some other configuration in there experimentally instead ... say ... nexenta. Assuming it will be just as good at zfs receive from the primary server. Is there some specific hardware configuration you guys sell? Or recommend? How about a Dell R510/R610/R710? Buy the hardware separately and buy NexentaStor as just a software product? Or buy a somehow more certified hardware software bundle together? If I do encounter a bug, where the only known fact is that the system keeps crashing intermittently on an approximately weekly basis, and there is absolutely no clue what's wrong in hardware or software... How do you guys handle it? If you'd like to follow up offlist, that's fine. Then just email me at the email address: nexenta at nedharvey.com (I use disposable email addresses on mailing lists like this, so at any random unknown time, I'll destroy my present alias and start using a new one.) ___ Hmm… that'd interest me as well - I do have 4 Dell PE R610, that are running OSol or Sol11Expr. I actually bought a Sun Fire X4170 M2, since I couldn't get my R610 stable, just as Edward points out. So, if you guys think that NexentaStor avoids these issues, then I'd seriously consider to jumpship - so either please don't continue offlist, or please include me in that conversation. ;) Cheers, budy ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
[zfs-discuss] pool metadata corrupted - any options?
Running zpool status -x gives the results below. Do I have any options besides restoring from tape? David $ zpool status -x pool: home state: FAULTED status: The pool metadata is corrupted and the pool cannot be opened. action: Destroy and re-create the pool from a backup source. see: http://www.sun.com/msg/ZFS-8000-72 scrub: none requested config: NAME STATE READ WRITE CKSUM home FAULTED 0 0 1 corrupted data raidz2 ONLINE 0 0 6 c0t10d0 ONLINE 0 0 0 c0t11d0 ONLINE 0 0 0 c0t12d0 ONLINE 0 0 0 c0t13d0 ONLINE 0 0 0 c0t14d0 ONLINE 0 0 0 c0t15d0 ONLINE 0 0 0 c0t16d0 ONLINE 0 0 0 c0t17d0 ONLINE 0 0 0 c0t18d0 ONLINE 0 0 0 c0t19d0 ONLINE 0 0 0 c0t20d0 ONLINE 0 0 0 c0t21d0 ONLINE 0 0 1 c0t22d0 ONLINE 0 0 0 c0t23d0 ONLINE 0 0 0 c0t2d0 ONLINE 0 0 0 c0t3d0 ONLINE 0 0 0 c0t4d0 ONLINE 0 0 0 c0t5d0 ONLINE 0 0 0 c0t6d0 ONLINE 0 0 0 c0t7d0 ONLINE 0 0 0 ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] A few questions
On 01/ 8/11 10:43 AM, Stephan Budach wrote: Am 08.01.11 18:33, schrieb Edward Ned Harvey: From: zfs-discuss-boun...@opensolaris.org [mailto:zfs-discuss- boun...@opensolaris.org] On Behalf Of Garrett D'Amore When you purchase NexentaStor from a top-tier Nexenta Hardware Partner, you get a product that has been through a rigorous qualification process How do I do this, exactly? I am serious. Before too long, I'm going to need another server, and I would very seriously consider reprovisioning my unstable Dell Solaris server to become a linux or some other stable machine. The role it's currently fulfilling is the backup server, which basically does nothing except zfs receive from the primary Sun solaris 10u9 file server. Since the role is just for backups, it's a perfect opportunity for experimentation, hence the Dell hardware with solaris. I'd be happy to put some other configuration in there experimentally instead ... say ... nexenta. Assuming it will be just as good at zfs receive from the primary server. Is there some specific hardware configuration you guys sell? Or recommend? How about a Dell R510/R610/R710? Buy the hardware separately and buy NexentaStor as just a software product? Or buy a somehow more certified hardware software bundle together? If I do encounter a bug, where the only known fact is that the system keeps crashing intermittently on an approximately weekly basis, and there is absolutely no clue what's wrong in hardware or software... How do you guys handle it? Such problems are handled on a case by case basis. Usually we can do some analysis from a crash dump, but not always. My team includes several people who are experienced with such analysis, and when problems like this occur, we are called into action. Ultimately this usually results in a patch, sometimes workaround suggestions, and sometimes even binary relief (which happens faster than a regular patch, but without the deeper QA.) - Garrett ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] (Fletcher+Verification) versus (Sha256+No Verification)
On Thu, 6 Jan 2011, David Magda wrote: If you're not worried about disk read errors (and/or are not experiencing them), then you shouldn't be worried about has collisions. Except for the little problem that if there is a collision then there will always be a collision for the same data and it is unavoidable. :-) Bit rot is a different sort of problem. Bob -- Bob Friesenhahn bfrie...@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/ GraphicsMagick Maintainer,http://www.GraphicsMagick.org/ ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
