[zfs-discuss] zpool on raw disk. Do I need to format?

2010-07-01 Thread Peter Taps
Folks, I am learning more about zfs storage. It appears, zfs pool can be created on a raw disk. There is no need to create any partitions, etc. on the disk. Does this mean there is no need to run format on a raw disk? I have added a new disk to my system. It shows up as /dev/rdsk/c8t1d0s0. Do

Re: [zfs-discuss] zpool on raw disk. Do I need to format?

2010-07-01 Thread Peter Taps
Awesome. Thank you, CIndy. Regards, Peter -- 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] zfs - filesystem versus directory

2010-07-02 Thread Peter Taps
Thank you all, especially Edward, for the enlightenment. Regards, Peter -- This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss

[zfs-discuss] Legality and the future of zfs...

2010-07-07 Thread Peter Taps
Folks, As you may have heard, NetApp has a lawsuit against Sun in 2007 (and now carried over to Oracle) for patent infringement with the zfs file system. Now, NetApp is taking a stronger stance and threatening zfs storage suppliers to stop selling zfs-based storage.

Re: [zfs-discuss] Legality and the future of zfs...

2010-07-09 Thread Peter Taps
Folks, I would appreciate it if you can create a separate thread for Mac Mini. Back to the original subject. NetApp has deep pockets. A few companies have already backed out of zfs as they cannot afford to go through a lawsuit. I am in a stealth startup company and we rely on zfs for our

[zfs-discuss] Is there any support for bi-directional synchronization in zfs?

2010-07-14 Thread Peter Taps
Folks, This is probably a very naive question. Is it possible to set zfs for bi-directional synchronization of data across two locations? I am thinking this is almost impossible. Consider two files A and B at two different sites. There are three possible cases that require synchronization:

[zfs-discuss] ZFS + WebDAV + AD integration

2010-07-14 Thread Peter Taps
Folks, I now know that ZFS is capable of preserving AD account sids. I have verified the scenario with CIFS integration. I am now wondering if it is possible to achieve a similar AD integration over WebDAV. Is it possible to retain security permissions on files and folders over WebDAV? Thank

Re: [zfs-discuss] Encryption?

2010-07-14 Thread Peter Taps
Btw, if you want a commercially supported and maintained product, have you looked at NexentaStor? Regardless of what happens with OpenSolaris, we aren't going anywhere. (Full disclosure: I'm a Nexenta Systems employee. :-) -- Garrett Hi Garrett, I would like to know why you think Nexenta

[zfs-discuss] How to identify user-created zfs filesystems?

2010-08-04 Thread Peter Taps
Folks, In my application, I need to present user-created filesystems. For my test, I created a zfs pool called mypool and two file systems called cifs1 and cifs2. However, when I run zfs list, I see a lot more entries: # zfs list NAME USED AVAIL REFER MOUNTPOINT mypool

Re: [zfs-discuss] How to identify user-created zfs filesystems?

2010-08-05 Thread Peter Taps
Thank you all for your help. It turns out that I just need to ignore the ones that have their mount points either not defined or are marked as legacy. It is good to learn about history command. Could come in handy. Regards, Peter -- This message posted from opensolaris.org

[zfs-discuss] Raidz - what is stored in parity?

2010-08-10 Thread Peter Taps
Hi, I am going through understanding the fundamentals of raidz. From the man pages, a raidz configuration of P disks and N parity provides (P-N)*X storage space where X is the size of the disk. For example, if I have 3 disks of 10G each and I configure it with raidz1, I will have 20G of usable

Re: [zfs-discuss] Raidz - what is stored in parity?

2010-08-10 Thread Peter Taps
Hi Eric, Thank you for your help. At least one part is clear now. I still am confused about how the system is still functional after one disk fails. Consider my earlier example of 3 disks zpool configured for raidz-1. To keep it simple let's not consider block sizes. Let's say I send a write

Re: [zfs-discuss] Raidz - what is stored in parity?

2010-08-11 Thread Peter Taps
Thank you all for your help. It appears my understanding of parity was rather limited. I kept on thinking about parity in memory where the extra bit would be used to ensure that the total of all 9 bits is always even. In case of zfs, the above type of checking is actually moved into checksum.

Re: [zfs-discuss] Raidz - what is stored in parity?

2010-08-11 Thread Peter Taps
I am running ZFS file system version 5 on Nexenta. Peter -- 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] Raidz - what is stored in parity?

2010-08-11 Thread Peter Taps
Thank you, Eric. Your explanation is clear to understand. Regards, Peter -- This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss

[zfs-discuss] How to obtain vdev information for a zpool?

2010-08-11 Thread Peter Taps
Folks, When I create a zpool, I get to specify the vdev type - mirror, raidz1, raidz2, etc. How do I get back this information for an existing pool? The status command does not reveal this information: # zpool status mypool When this command is run, I can see the disks in use. However, I

Re: [zfs-discuss] How to obtain vdev information for a zpool?

2010-08-12 Thread Peter Taps
Hi James, Appreciate your help. Regards, Peter -- This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss

[zfs-discuss] Dedup - Does on imply sha256?

2010-08-24 Thread Peter Taps
Folks, One of the articles on the net says that the following two commands are exactly the same: # zfs set dedup=on tank # zfs set dedup=sha256 tank Essentially, on is just a pseudonym for sha256 and verify is just a pseudonym for sha256,verify. Can someone please confirm if this is true?

Re: [zfs-discuss] Dedup - Does on imply sha256?

2010-08-25 Thread Peter Taps
Thank you all for your help. It appears it is better to use on instead of sha256. This way, you are letting zfs decide the best option. Regards, Peter -- This message posted from opensolaris.org ___ zfs-discuss mailing list

Re: [zfs-discuss] Possible to save custom properties on a zfs file system?

2010-09-20 Thread Peter Taps
Thank you all for your help. Can properties be set on file systems as well as pools? When I try zpool set command with a local property, I can an error invalid property. Regards, Peter -- This message posted from opensolaris.org ___ zfs-discuss

[zfs-discuss] What is l2cache setting?

2010-09-22 Thread Peter Taps
Folks, While going through zpool source code, I see a configuration option called l2cache. What is this option for? It doesn't seem to be documented. Thank you in advance for your help. Regards, Peter -- This message posted from opensolaris.org ___

Re: [zfs-discuss] What is l2cache setting?

2010-09-22 Thread Peter Taps
Neil, Thank you for your help. However, I don't see anything about l2cache under Cache devices man pages. To be clear, there are two different vdev types defined in zfs source code - cache and l2cache. I am familiar with cache devices. I am curious about l2cache devices. Regards, Peter --

[zfs-discuss] Feature differences between Solaris 10 9/10 and build 147

2010-09-22 Thread Peter Taps
Folks, Here is the list of ZFS enhancements as mentioned for the latest Solaris 10 update: * ZFS device replacement enhancements - namely autoexpand * some changes to the zpool list command * Holding ZFS snapshots * Triple parity RAID-Z (raidz3) * The logbias property *

[zfs-discuss] Dedup relationship between pool and filesystem

2010-09-23 Thread Peter Taps
Folks, I am a bit confused on the dedup relationship between the filesystem and its pool. The dedup property is set on a filesystem, not on the pool. However, the dedup ratio is reported on the pool and not on the filesystem. Why is it this way? Thank you in advance for your help. Regards,

[zfs-discuss] What is dedupditto property on zpool?

2010-09-24 Thread Peter Taps
Folks, One of the zpool properties that is reported is dedupditto. However, there is no documentation available, either in man pages or anywhere else on the Internet. What exactly is this property? Thank you in advance for your help. Regards, Peter -- This message posted from opensolaris.org

[zfs-discuss] Any zfs fault injection tools?

2010-09-24 Thread Peter Taps
Folks, Command zpool status reports disk status that includes read errors, write errors, and checksum errors. These values have always been 0 in our test environment. Is there any tool out there that can corrupt the state? At the very least, we should be able to write to the disk directly and

Re: [zfs-discuss] Any zfs fault injection tools?

2010-09-24 Thread Peter Taps
Freddie, Thank you very much for your help. Regards, Peter -- This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss

[zfs-discuss] When is it okay to turn off the verify option.

2010-10-04 Thread Peter Taps
Folks, As I understand, the hash generated by sha256 is almost guaranteed not to collide. I am thinking it is okay to turn off verify property on the zpool. However, if there is indeed a collision, we lose data. Scrub cannot recover such lost data. I am wondering in real life when is it okay

[zfs-discuss] Optimal raidz3 configuration

2010-10-13 Thread Peter Taps
Folks, If I have 20 disks to build a raidz3 pool, do I create one big raidz vdev or do I create multiple raidz3 vdevs? Is there any advantage of having multiple raidz3 vdevs in a single pool? Thank you in advance for your help. Regards, Peter -- This message posted from opensolaris.org

[zfs-discuss] How does dedup work over iSCSI?

2010-10-22 Thread Peter Taps
Folks, Let's say I have a volume being shared over iSCSI. The dedup has been turned on. Let's say I copy the same file twice under different names at the initiator end. Let's say each file ends up taking 5 blocks. For dedupe to work, each block for a file must match the corresponding block

Re: [zfs-discuss] How does dedup work over iSCSI?

2010-10-22 Thread Peter Taps
Hi Neil, if the file offset does not match, the chances that the checksum would match, especially sha256, is almost 0. May be I am missing something. Let's say I have a file that contains 11 letters - ABCDEFGHIJK. Let's say the block size is 5. For the first file, the block contents are

[zfs-discuss] Any limit on pool hierarchy?

2010-11-08 Thread Peter Taps
Folks, From zfs documentation, it appears that a vdev can be built from more vdevs. That is, a raidz vdev can be built across a bunch of mirrored vdevs, and a mirror can be built across a few raidz vdevs. Is my understanding correct? Also, is there a limit on the depth of a vdev? Thank you

[zfs-discuss] How to create a checkpoint?

2010-11-08 Thread Peter Taps
Folks, My understanding is that there is a way to create a zfs checkpoint before doing any system upgrade or installing a new software. If there is a problem, one can simply rollback to the stable checkpoint. I am familiar with snapshots and clones. However, I am not clear on how to manage

Re: [zfs-discuss] How to create a checkpoint?

2010-11-09 Thread Peter Taps
Thank you all for your help. Looks like beadm is the utility I was looking for. When I run beadm list, it gives me the complete list and indicates which one is currently active. It doesn't tell me which one is the default boot. Can I assume that whatever is active is also the default?

[zfs-discuss] How to grow root vdevs?

2010-11-09 Thread Peter Taps
Folks, I am trying to understand if there is a way to increase the capacity of a root-vdev. After reading zpool man pages, the following is what I understand: 1. If you add a new disk by using zpool add, this disk gets added as a new root-vdev. The existing root-vdevs are not changed. 2. You

Re: [zfs-discuss] How to grow root vdevs?

2010-11-10 Thread Peter Taps
Thank you for your help. Regards, Peter -- This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss

[zfs-discuss] How to safely parse zpool get all output?

2010-12-06 Thread Peter Taps
Folks, Command zpool get all poolName does not provide any option to generate parsable output. The returned output contains 4 fields - name, property, value and source. These fields seems to be separated by spaces. I am wondering if it is safe to assume that there are no spaces in the field

Re: [zfs-discuss] How to safely parse zpool get all output?

2010-12-06 Thread Peter Taps
Hi, Thank you for your help. I actually had the script working. However, I just wanted to make sure that spaces are not permitted within the field value itself. Otherwise, the regular expression would break. Regards, Peter -- This message posted from opensolaris.org

[zfs-discuss] (Fletcher+Verification) versus (Sha256+No Verification)

2011-01-06 Thread Peter Taps
Folks, I have been told that the checksum value returned by Sha256 is almost guaranteed to be unique. In fact, if Sha256 fails in some case, we have a bigger problem such as memory corruption, etc. Essentially, adding verification to sha256 is an overkill. Perhaps (Sha256+NoVerification)

Re: [zfs-discuss] (Fletcher+Verification) versus (Sha256+No Verification)

2011-01-09 Thread Peter Taps
Thank you all for your help. I am the OP. I haven't looked at the link that talks about the probability of collision. Intuitively, I still wonder how the chances of collision can be so low. We are reducing a 4K block to just 256 bits. If the chances of collision are so low, *theoretically* it

[zfs-discuss] How to increase iometer reading?

2011-01-09 Thread Peter Taps
Hello, We are building a zfs-based storage system with generic but high-quality components. We would like to test the new system under various loads. If we find that the iometer reading has started to reduce under certain loads, I am wondering what performance counters we should look for to

Re: [zfs-discuss] (Fletcher+Verification) versus (Sha256+No Verification)

2011-01-14 Thread Peter Taps
Ed, Thank you for sharing the calculations. In lay terms, for Sha256, how many blocks of data would be needed to have one collision? Assuming each block is 4K is size, we probably can calculate the final data size beyond which the collision may occur. This would enable us to make the

Re: [zfs-discuss] (Fletcher+Verification) versus (Sha256+No Verification)

2011-01-14 Thread Peter Taps
I am posting this once again as my previous post went into the middle of the thread and may go unnoticed. Ed, Thank you for sharing the calculations. In lay terms, for Sha256, how many blocks of data would be needed to have one collision? Assuming each block is 4K is size, we probably can