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bio website nex7.com
location Mercer Island, WA
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visits member for 3 years, 5 months
seen Jul 8 at 18:28

( http://www.nexenta.com )

I am a Solutions Architect at Nexenta Systems, Inc, formerly a Nexenta Support Engineer.

My involvement in this website is strictly voluntary, and on my own initiative as time allows. Please do not message me privately about active NexentaStor support cases. If you have a Nexenta or ZFS-related question on ServerFault, I don't mind if you ping me with a link and request I take a look, but I cannot guarantee a response, much less a timely one.

I do not represent Nexenta in any official capacity on this site, and my comments/posts are my own, and do not represent official Nexenta responses or policy.


Mar
22
comment ZFS pool is empty after crash
"...but they're all a bit more unpolished and potentially destructive than I'd like at this point..." - this comment is ironic, considering you chose to put data on ZFS on Linux v0.6.0rc11. You're already deep in "not production ready" territory here. I'm not trying to be snarky - this is seriously exactly what you should have expected to happen. If you want to run ZFS with data you want to keep around, use FreeBSD or an illumos derivative. Period. As for your question, those 'unpolished and potentially destructive' tools are your only hope. Try Max Bruning's post on zdb for a starting point.
Mar
22
answered How to find files with top io on solaris ZFS?
Apr
15
awarded  Yearling
Mar
20
answered preserve permission with scp
Mar
20
comment check max_used_connections with out logging into mysql in ubuntu
Oh and bear in mind this is a potential security risk. Be sure to set permissions on ~/.my.cnf to prevent access by unauthorized users, OR create a user in MySQL that only has the minimum privileges required to get what you want and make that the username you have in this file.
Mar
20
answered check max_used_connections with out logging into mysql in ubuntu
Mar
20
comment Install MegaCli to Monitor Perc 5/i in Nexentastor 3
Your paste doesn't actually show it failing to do the job. You have to understand that Nexenta may be a Solaris kernel, but it doesn't use Solaris PACKAGES (.pkg files). Instead, when you do pkgadd on Nexenta, it is running a script that rips that .pkg apart and attempts to create a .deb out of it, then install the .deb. The last line of your paste seems to indicate it was attempting to do so. Did it fail later than shown in this paste?
Mar
20
answered Is a large RAID-Z array just as bad as a large RAID-5 array?
Mar
20
awarded  Commentator
Mar
20
comment Poor ZFS (raidz) i/o performance in Debian
If you run an iostat -xen while the bonnie is running, what's the output look like for asvc_t and wsvc_t on the pool disks? I note from your bonnie output that the latencies reported for the ZFS pool are 100+ms. That's just flat out pathetic. Something is very wrong. If wsvc_t is higher than like 0.3, the controller you're using is crap/overloaded; if asvc_t is getting over 20-30ms ever, your disks are bad or being talked to poorly, etc. Also since you have no ZIL device, for testing I'd suggest disabling ZIL mechanics..
Feb
28
comment Since upgrading to Solaris 11, my ARC size has consistently targeted 119MB, despite having 30GB RAM. What? Why?
In the event this isn't a mistake in what you're looking at and you genuinely have an oddity there, please note you CAN modify these values on the fly on a live system, or permanently using /etc/system.
Feb
28
comment When using thin-provisioning with ZFS, how do you make sure you don't run out of physical disk space?
Just dd'ing at the disk is obviously no good if there's DATA on it. For zvols containing filesystems, you need to get a bit more creative. For Windows users, you can run "sdelete -c" (Google "sdelete"). For Linux, ext2/3 (and I assume 4?) there's a utility out there called "zerofree", I know Ubuntu has it in default repos. Obviously you need to run these on a client machine with the disk mounted up, not on Nexenta itself.
Feb
28
comment Where can I find introductory documentation for ZFS?
Appreciate the comment - that was indeed my purpose with it; not too narrowly focused on just that, but in large part it was written in response to seeing many, many setups where the ultimate problem was in certain misunderstandings or mis-configurations during initial build. I think a key take-away is that even if you have years of traditional storage experience, ZFS will throw you for a loop on a couple of things (like more disks not necessarily equaling more IOPS) if you don't read up on it. Plus it is making "enterprise" storage available to entire groups who just never had it before.
Feb
27
answered Where can I find introductory documentation for ZFS?
Feb
27
awarded  Tag Editor
Feb
27
revised zfs wiki description
added mention of illumos and 3 of the main distributions built on it - remove mention of Nexenta NCP because NCP is being replaced by Nexenta's illumian
Feb
27
suggested suggested edit on zfs tag wiki
Feb
27
comment Undelete ZFS file shared by Samba
@pauska Yes, it is. Sort of. Again, ZFS is keeping a rolling queue of the last 128 updates to the global pool, if you will. So effectively you have 128 point-in-time snapshots representing the last few minutes to hours (depending on configuration). You can both traverse these (if you're good, know what you're looking for, and have a bit of luck on your side), or you can 'roll back' to one of these (losing everything between it and present time, unfortunately). This is very advanced ZFS fu -- it is NOT meant to be used as a scapegoat for not using real snapshots or poor implementation/planning.
Feb
25
comment Undelete ZFS file shared by Samba
If you ever find yourself realizing you just deleted something SUPER IMPORTANT, immediately export the pool and call an expert (you need to export the pool; just stopping your access is almost undoubtedly insufficient, as would be pulling the network cable from the storage device -- export the pool to be safe, and call for help).
Feb
25
comment Undelete ZFS file shared by Samba
@TomPaine - zdb-fu would have only been an available option had it been attempted fairly quickly after the file was deleted. It is both possible to potentially rip the file out of an older uberblock, or it is possible to roll back the entire ZFS pool to an earlier point in time.. but in both cases, only for the last 128 or so txg's -- which depending on version and load could be gone in just over 10 minutes or an hour. This is an extremely risky procedure that should only be undertaken by someone with experience doing it.