Re: [zfs-discuss] hard drive write cache

2006-05-26 Thread Neil Perrin
ZFS enables the write cache and flushes it when committing transaction groups; this insures that all of a transaction group appears or does not appear on disk. It also flushes the disk write cache before returning from every synchronous request (eg fsync, O_DSYNC). This is done after writing

Re: [zfs-discuss] 15 minute fdsync problem and ZFS: Solved

2006-06-21 Thread Neil Perrin
Well this does look more and more like a duplicate of: 6413510 zfs: writing to ZFS filesystem slows down fsync() on other files in the same FS Neil ___ zfs-discuss mailing list zfs-discuss@opensolaris.org

Re: [zfs-discuss] 15 minute fdsync problem and ZFS: Solved

2006-06-21 Thread Neil Perrin
Torrey McMahon wrote On 06/21/06 10:29,: Roch wrote: Sean Meighan writes: The vi we were doing was a 2 line file. If you just vi a new file, add one line and exit it would take 15 minutes in fdsynch. On recommendation of a workaround we set set zfs:zil_disable=1 after the

Re: [zfs-discuss] 15 minute fdsync problem and ZFS: Solved

2006-06-21 Thread Neil Perrin
Robert Milkowski wrote On 06/21/06 11:09,: Hello Neil, Why is this option available then? (Yes, that's a loaded question.) NP I wouldn't call it an option, but an internal debugging switch that I NP originally added to allow progress when initially integrating the ZIL. NP As Roch says it

Re: [zfs-discuss] Bandwidth disparity between NFS and ZFS

2006-06-24 Thread Neil Perrin
Chris, The data will be written twice on ZFS using NFS. This is because NFS on closing the file internally uses fsync to cause the writes to be committed. This causes the ZIL to immediately write the data to the intent log. Later the data is also written committed as part of the pools

Re: [zfs-discuss] Bandwidth disparity between NFS and ZFS

2006-06-26 Thread Neil Perrin
Robert Milkowski wrote On 06/25/06 04:12,: Hello Neil, Saturday, June 24, 2006, 3:46:34 PM, you wrote: NP Chris, NP The data will be written twice on ZFS using NFS. This is because NFS NP on closing the file internally uses fsync to cause the writes to be NP committed. This causes the ZIL

Re: [zfs-discuss] Bandwidth disparity between NFS and ZFS

2006-06-27 Thread Neil Perrin
Robert Milkowski wrote On 06/27/06 03:00,: Hello Chris, Tuesday, June 27, 2006, 1:07:31 AM, you wrote: CC On 6/26/06, Neil Perrin [EMAIL PROTECTED] wrote: Robert Milkowski wrote On 06/25/06 04:12,: Hello Neil, Saturday, June 24, 2006, 3:46:34 PM, you wrote: NP Chris, NP The data

Re: [zfs-discuss] Supporting ~10K users on ZFS

2006-06-27 Thread Neil Perrin
[EMAIL PROTECTED] wrote On 06/27/06 17:17,: We have over 1 filesystems under /home in strongspace.com and it works fine. I forget but there was a bug or there was an improvement made around nevada build 32 (we're currently at 41) that made the initial mount on reboot significantly

Re: [zfs-discuss] 15 minute fdsync problem and ZFS: Solved

2006-06-28 Thread Neil Perrin
Robert Milkowski wrote On 06/28/06 15:52,: Hello Neil, Wednesday, June 21, 2006, 8:15:54 PM, you wrote: NP Robert Milkowski wrote On 06/21/06 11:09,: Hello Neil, Why is this option available then? (Yes, that's a loaded question.) NP I wouldn't call it an option, but an internal

Re: [zfs-discuss] Re: zvol Performance

2006-07-17 Thread Neil Perrin
This is change request: 6428639 large writes to zvol synchs too much, better cut down a little which I have a fix for, but it hasn't been put back. Neil. Jürgen Keil wrote On 07/17/06 04:18,: Further testing revealed that it wasn't an iSCSI performance issue but a zvol issue. Testing on a

Re: [zfs-discuss] How to best layout our filesystems

2006-07-26 Thread Neil Perrin
Brian Hechinger wrote On 07/26/06 06:49,: On Tue, Jul 25, 2006 at 03:54:22PM -0700, Eric Schrock wrote: If you give zpool(1M) 'whole disks' (i.e. no 's0' slice number) and let it label and use the disks, it will automatically turn on the write cache for you. What if you can't give ZFS

Re: [zfs-discuss] zil_disable

2006-08-07 Thread Neil Perrin
Not quite, zil_disable is inspected on file system mounts. It's also looked at dynamically on every write for zvols. Neil. Robert Milkowski wrote On 08/07/06 10:07,: Hello zfs-discuss, Just a note to everyone experimenting with this - if you change it online it has only effect when pools

Re: [zfs-discuss] zil_disable

2006-08-08 Thread Neil Perrin
Robert Milkowski wrote: Hello Neil, Monday, August 7, 2006, 6:40:01 PM, you wrote: NP Not quite, zil_disable is inspected on file system mounts. I guess you right that umount/mount will suffice - I just hadn't time to check it and export/import worked. Anyway is there a way for file systems

Re: [zfs-discuss] zil_disable

2006-08-08 Thread Neil Perrin
Robert Milkowski wrote: Hello Eric, Monday, August 7, 2006, 6:29:45 PM, you wrote: ES Robert - ES This isn't surprising (either the switch or the results). Our long term ES fix for tweaking this knob is: ES 6280630 zil synchronicity ES Which would add 'zfs set sync' as a per-dataset

Re: [zfs-discuss] Re: ZFS RAID10

2006-08-10 Thread Neil Perrin
Robert Milkowski wrote: Hello Matthew, Thursday, August 10, 2006, 6:55:41 PM, you wrote: MA On Thu, Aug 10, 2006 at 06:50:45PM +0200, Robert Milkowski wrote: btw: wouldn't it be possible to write block only once (for synchronous IO) and than just point to that block instead of copying it

Re: [zfs-discuss] Re: ZFS RAID10

2006-08-10 Thread Neil Perrin
Robert Milkowski wrote: Hello Neil, Thursday, August 10, 2006, 7:02:58 PM, you wrote: NP Robert Milkowski wrote: Hello Matthew, Thursday, August 10, 2006, 6:55:41 PM, you wrote: MA On Thu, Aug 10, 2006 at 06:50:45PM +0200, Robert Milkowski wrote: btw: wouldn't it be possible to write

Re: [zfs-discuss] fdatasync

2006-08-10 Thread Neil Perrin
Myron Scott wrote: Is there any difference between fdatasync and fsync on ZFS? -No. ZFS does not log data and meta data separately. rather it logs essentially the system call records, eg writes, mkdir, truncate, setattr, etc. So fdatasync and fsync are identical on ZFS.

Re: [zfs-discuss] Significant pauses during zfs writes

2006-08-14 Thread Neil Perrin
Yes James is right this is normal behaviour. Unless the writes are synchronous (O_DSYNC) or explicitely flushed (fsync()) then they are batched up, written out and committed as a transaction every txg_time (5 seconds). Neil. James C. McPherson wrote: Bob Evans wrote: Just getting my feet wet

Re: [zfs-discuss] Re: 3510 HW RAID vs 3510 JBOD ZFS SOFTWARE RAID

2006-08-14 Thread Neil Perrin
Robert Milkowski wrote: ps. however I'm really concerned with ZFS behavior when a pool is almost full, there're lot of write transactions to that pool and server is restarted forcibly or panics. I observed that file systems on that pool will mount in 10-30 minutes each during zfs mount -a, and

Re: [zfs-discuss] Re: Bizzare problem with ZFS filesystem

2006-09-15 Thread Neil Perrin
It is highly likely you are seeing a duplicate of: 6413510 zfs: writing to ZFS filesystem slows down fsync() on other files in the same FS which was fixed recently in build 48 on Nevada. The symptoms are very similar. That is a fsync from the vi would, prior to the bug being fixed, have

Re: [zfs-discuss] Importing ZFS filesystems across architectures...

2006-09-21 Thread Neil Perrin
Philip Brown wrote On 09/21/06 20:28,: Eric Schrock wrote: If you're using EFI labels, yes (VTOC labels are not endian neutral). ZFS will automatically convert endianness from the on-disk format, and new data will be written using the native endianness, so data will be gradually be rewritten

Re: [zfs-discuss] panic string assistance

2006-10-03 Thread Neil Perrin
ZFS will currently panic on a write failure to a non replicated pool. In the case below the Intent Log (though it could have been any module) could not write an intent log block. Here's a previous response from Eric Schrock explaining how ZFS intends to handle this:

Re: [zfs-discuss] fsflush and zfs

2006-10-13 Thread Neil Perrin
ZFS ignores the fsflush. Here's a snippet of the code in zfs_sync(): /* * SYNC_ATTR is used by fsflush() to force old filesystems like UFS * to sync metadata, which they would otherwise cache indefinitely. * Semantically, the only requirement is that the sync

Re: [zfs-discuss] Snapshots impact on performance

2006-10-16 Thread Neil Perrin
Matthew Ahrens wrote On 10/16/06 09:07,: Robert Milkowski wrote: Hello zfs-discuss, S10U2+patches. ZFS pool of about 2TB in size. Each day snapshot is created and 7 copies are kept. There's quota set for a file system however there's always at least 50GB of free space in a file system

Re: [zfs-discuss] Re: Porting ZFS file system to FreeBSD.

2006-10-27 Thread Neil Perrin
Pawel, I second that praise. Well done! Attached is a copy of ziltest. You will have to adapt this a bit to your environment. In particular it uses bringover to pull a subtree of our source and then builds and later runs it. This tends to create a fair number of transactions with various

Re: [zfs-discuss] Re: Re: ZFS hangs systems during copy

2006-10-27 Thread Neil Perrin
Jürgen Keil wrote On 10/27/06 11:55,: This is: 6483887 without direct management, arc ghost lists can run amok That seems to be a new bug? http://bugs.opensolaris.org does not yet find it. It's not so new as it was created on 10/19, but as you say bug search doesn't find it. However, you

Re: [zfs-discuss] linux versus sol10

2006-11-08 Thread Neil Perrin
Robert Milkowski wrote On 11/08/06 08:16,: Hello Paul, Wednesday, November 8, 2006, 3:23:35 PM, you wrote: PvdZ On 7 Nov 2006, at 21:02, Michael Schuster wrote: listman wrote: hi, i found a comment comparing linux and solaris but wasn't sure which version of solaris was being referred.

Re: [zfs-discuss] Some performance questions with ZFS/NFS/DNLC at snv_48

2006-11-09 Thread Neil Perrin
Tomas Ögren wrote On 11/09/06 09:59,: 1. DNLC-through-ZFS doesn't seem to listen to ncsize. The filesystem currently has ~550k inodes and large portions of it is frequently looked over with rsync (over nfs). mdb said ncsize was about 68k and vmstat -s said we had a hitrate of ~30%, so I set

Re: [zfs-discuss] Some performance questions with ZFS/NFS/DNLC at snv_48

2006-11-09 Thread Neil Perrin
Tomas Ögren wrote On 11/09/06 13:47,: On 09 November, 2006 - Neil Perrin sent me these 1,6K bytes: Tomas Ögren wrote On 11/09/06 09:59,: 1. DNLC-through-ZFS doesn't seem to listen to ncsize. The filesystem currently has ~550k inodes and large portions of it is frequently looked

Re: [zfs-discuss] zfs mount stuck in zil_replay

2006-11-09 Thread Neil Perrin
Hi Robert, Yes, it could be related, or even the bug. Certainly the replay was (prior to this bug fix) extremely slow. I don't really have enough information to determine if it's the exact problem, though after re-reading your original post I strongly suspect it is. I also putback a companion

Re: [zfs-discuss] Re: Managed to corrupt my pool

2006-12-05 Thread Neil Perrin
Jim, I'm not at all sure what happened to your pool. However, I can answer some of your questions. Jim Hranicky wrote On 12/05/06 11:32,: So the questions are: - is this fixable? I don't see an inum I could run find on to remove, I think the pool is busted. Even the message printed in your

Re: [zfs-discuss] A Plea for Help: Thumper/ZFS/NFS/B43

2006-12-07 Thread Neil Perrin
Ben, The attached dscript might help determining the zfs_create issue. It prints: - a count of all functions called from zfs_create - average wall count time of the 30 highest functions - average cpu time of the 30 highest functions Note, please ignore warnings of the

Re: [zfs-discuss] Re: ZFS Storage Pool advice

2006-12-12 Thread Neil Perrin
Are you looking purely for performance, or for the added reliability that ZFS can give you? If the latter, then you would want to configure across multiple LUNs in either a mirrored or RAID configuration. This does require sacrificing some storage in exchange for the peace of mind that any

Re: [zfs-discuss] Monitoring ZFS

2006-12-12 Thread Neil Perrin
Tom Duell wrote On 12/12/06 17:11,: Group, We are running a benchmark with 4000 users simulating a hospital management system running on Solaris 10 6/06 on USIV+ based SunFire 6900 with 6540 storage array. Are there any tools for measuring internal ZFS activity to help us understand what is

Re: [zfs-discuss] Some ZFS questions

2006-12-17 Thread Neil Perrin
CT Will I be able to I tune the DMU flush rate, now set at 5 seconds? echo 'txg_time/D 0t1' | mdb -kw Er, that 'D' ahould be a 'W'. Having said that I don't think we recommend messing with the transaction group commit timing. ___ zfs-discuss mailing

Re: [zfs-discuss] Difference between ZFS and UFS with one LUN from a SAN

2006-12-22 Thread Neil Perrin
Robert Milkowski wrote On 12/22/06 13:40,: Hello Torrey, Friday, December 22, 2006, 9:17:46 PM, you wrote: TM Roch - PAE wrote: The fact that most FS do not manage the disk write caches does mean you're at risk of data lost for those FS. TM Does ZFS? I thought it just turned it on in

Re: [zfs-discuss] Solid State Drives?

2007-01-05 Thread Neil Perrin
I'm currently working on putting the ZFS intent log on separate devices which could include seperate disks and nvram/solid state devices. This would help any application using fsync/O_DSYNC - in particular DB and NFS. From protoyping considerable peformanace improvements have been seen. Neil.

Re: [zfs-discuss] Solid State Drives?

2007-01-05 Thread Neil Perrin
Robert Milkowski wrote On 01/05/07 11:45,: Hello Neil, Friday, January 5, 2007, 4:36:05 PM, you wrote: NP I'm currently working on putting the ZFS intent log on separate devices NP which could include seperate disks and nvram/solid state devices. NP This would help any application using

Re: [zfs-discuss] Puzzling ZFS behavior with COMPRESS option

2007-01-08 Thread Neil Perrin
Anantha N. Srirama wrote On 01/08/07 13:04,: Our setup: - E2900 (24 x 96); Solaris 10 Update 2 (aka 06/06) - 2 2Gbps FC HBA - EMC DMX storage - 50 x 64GB LUNs configured in 1 ZFS pool - Many filesystems created with COMPRESS enabled; specifically I've one that is 768GB I'm observing the

Re: [zfs-discuss] Re: Re: Heavy writes freezing system

2007-01-17 Thread Neil Perrin
Rainer Heilke wrote On 01/17/07 15:44,: It turns out we're probably going to go the UFS/ZFS route, with 4 filesystems (the DB files on UFS with Directio). It seems that the pain of moving from a single-node ASM to a RAC'd ASM is great, and not worth it. The DBA group decided doing the

Re: [zfs-discuss] Re: Re: Re: Heavy writes freezing system

2007-01-17 Thread Neil Perrin
Anton B. Rang wrote On 01/17/07 20:31,: Yes, Anantha is correct that is the bug id, which could be responsible for more disk writes than expected. I believe, though, that this would explain at most a factor of 2 of write expansion (user data getting pushed to disk once in the intent log,

Re: [zfs-discuss] bug id 6381203

2007-01-28 Thread Neil Perrin
Hi Leon, This was fixed in March 2006, and is in S10_U2. Neil. Leon Koll wrote On 01/28/07 08:58,: Hello, what is the status of the bug 6381203 fix in S10 u3 ? (deadlock due to i/o while assigning (tc_lock held)) Was it integrated? Is there a patch? Thanks, [i]-- leon[/i] This message

Re: [zfs-discuss] ZFS inode equivalent

2007-01-31 Thread Neil Perrin
No it's not the final version or even the latest! The current on disk format version is 3. However, it hasn't diverged much and the znode/acl stuff hasn't changed. Neil. James Blackburn wrote On 01/31/07 14:31,: Or look at pages 46-50 of the ZFS on-disk format document:

Re: [zfs-discuss] ZFS checksums - block or file level

2007-02-01 Thread Neil Perrin
ZFS checksums are at the block level. Nathan Essex wrote On 02/01/07 08:27,: I am trying to understand if zfs checksums apply at a file or a block level. We know that zfs provides end to end checksum integrity, and I assumed that when I write a file to a zfs filesystem, the checksum was

Re: [storage-discuss] Re[2]: [zfs-discuss] se3510 and ZFS

2007-02-06 Thread Neil Perrin
Robert Milkowski wrote On 02/06/07 11:43,: Hello eric, Tuesday, February 6, 2007, 5:55:23 PM, you wrote: IIRC Bill posted here some tie ago saying the problem with write cache on the arrays is being worked on. ek Yep, the bug is: ek 6462690 sd driver should set SYNC_NV bit when issuing

Re: [zfs-discuss] Efficiency when reading the same file blocks

2007-02-25 Thread Neil Perrin
Jeff Davis wrote On 02/25/07 20:28,: if you have N processes reading the same file sequentially (where file size is much greater than physical memory) from the same starting position, should I expect that all N processes finish in the same time as if it were a single process? Yes I would

Re: [zfs-discuss] Today PANIC :(

2007-02-28 Thread Neil Perrin
Gino, We have ween this before but only very rarely and never got a good crash dump. Coincidently, we saw it only yesterday on a server here, and are currently investigating it. Did you also get a dump we can access? That would If not can you tell us what zfs version you were running. At the

Re: [zfs-discuss] mirror question

2007-03-23 Thread Neil Perrin
Yes, this is supported now. Replacing one half of a mirror with a larger device; letting it resilver; then replacing the other half does indeed get a larger mirror. I believe this is described somewhere but I can't remember where now. Neil. Richard L. Hamilton wrote On 03/23/07 20:45,: If I

Re: [zfs-discuss] Re: asize is 300MB smaller than lsize - why?

2007-03-24 Thread Neil Perrin
Matthew Ahrens wrote On 03/24/07 12:13,: Kangurek wrote: Thanks for info. My idea was to traverse changing filesystem, now I see that it will not work. I will try to traverse snapshots. Zreplicate will: 1. do snapshot @replicate_leatest and 2. send data to snapshot @replicate_leatest 3.

Re: [zfs-discuss] Re: asize is 300MB smaller than lsize - why?

2007-03-24 Thread Neil Perrin
Matthew Ahrens wrote On 03/24/07 12:36,: Neil Perrin wrote: I'm not sure exactly what will be slow about taking snapshots, but one aspect might be that we have to suspend the intent log (see call to zil_suspend() in dmu_objset_snapshot_one()). I've been meaning to change that for a while

Re: [zfs-discuss] Size taken by a zfs symlink

2007-04-03 Thread Neil Perrin
Hi Robert, Robert Milkowski wrote On 04/02/07 17:48,: Right now a symlink should consume one dnode (320 bytes) dnode_phys_t are actually 512 bytes: ::sizeof dnode_phys_t sizeof (dnode_phys_t) = 0x200 if the name it point to is less than 67 bytes, otherwise a data block is allocated

Re: [zfs-discuss] HowTo: UPS + ZFS NFS + no fsync

2007-04-26 Thread Neil . Perrin
cedric briner wrote: You might set zil_disable to 1 (_then_ mount the fs to be shared). But you're still exposed to OS crashes; those would still corrupt your nfs clients. -r hello Roch, I've few questions 1) from: Shenanigans with ZFS flushing and intelligent arrays...

Re: [zfs-discuss] recovered state after system crash

2007-05-04 Thread Neil Perrin
kyusun Chang wrote On 05/04/07 19:34,: If system crashes some time after last commit of transaction group (TxG), what happens to the file system transactions since the last commit of TxG They are lost, unless they were synchronous (see below). (I presume last commit of TxG represents the

Re: [zfs-discuss] does every fsync() require O(log n) platter-writes?

2007-05-06 Thread Neil . Perrin
Adam Megacz wrote: After reading through the ZFS slides, it appears to be the case that if ZFS wants to modify a single data block, if must rewrite every block between that modified block and the uberblock (root of the tree). Is this really the case? That is true when commiting the

Re: [zfs-discuss] Re: does every fsync() require O(log n) platter-writes?

2007-05-06 Thread Neil . Perrin
Adam Megacz wrote: Ah, okay. The slides I read said that in ZFS there is no journal -- not needed (slide #9): http://www.opensolaris.org/os/community/zfs/docs/zfs_last.pdf I guess the slides are out of date in light of the ZFS Intent Log journal? Yes , I can understand your confusion.

Re: [zfs-discuss] Re: How does ZFS write data to disks?

2007-05-11 Thread Neil . Perrin
lonny wrote: On May 11, 2007, at 9:09 AM, Bob Netherton wrote: **On Fri, 2007-05-11 at 09:00 -0700, lonny wrote: **I've noticed a similar behavior in my writes. ZFS seems to write in bursts of ** around 5 seconds. I assume it's just something to do with caching? ^Yep - the ZFS equivalent of

Re: [zfs-discuss] NFS and Tar/Star Performance

2007-06-12 Thread Neil . Perrin
eric kustarz wrote: Over NFS to non-ZFS drive - tar xfvj linux-2.6.21.tar.bz2 real5m0.211s,user0m45.330s,sys 0m50.118s star xfv linux-2.6.21.tar.bz2 real3m26.053s,user0m43.069s,sys 0m33.726s star -no-fsync -x -v -f

Re: [zfs-discuss] Difference between add and attach a device?

2007-06-14 Thread Neil . Perrin
Rick Mann wrote: Hi. I've been reading the ZFS admin guide, and I don't understand the distinction between adding a device and attaching a device to a pool? attach is used to create or add a side to a mirror. add is to add a new top level vdev where that can be a raidz, mirror or single

Re: [zfs-discuss] ZIL on user specified devices?

2007-06-22 Thread Neil Perrin
Bryna, Your timing is excellent! We've been working on this for a while now and hopefully within the next day I'll be adding support for separate log devices into Nevada. I'll send out more details soon... Neil. Bryan Wagoner wrote: Quick question, Are there any tunables, or is there any

Re: [zfs-discuss] Re: Drive Failure w/o Redundancy

2007-06-27 Thread Neil Perrin
Darren Dunham wrote: The problem I've come across with using mirror or raidz for this setup is that (as far as I know) you can't add disks to mirror/raidz groups, and if you just add the disk to the pool, you end up in the same situation as above (with more space but no redundancy). You

Re: [zfs-discuss] Take Three: PSARC 2007/171 ZFS Separate Intent Log

2007-07-07 Thread Neil Perrin
Cyril, I wrote this case and implemented the project. My problem was that I didn't know what policy (if any) Sun has about publishing ARC cases, and a mail log with a gazillion email addresses. I did receive an answer to this this in the form:

Re: [zfs-discuss] Take Three: PSARC 2007/171 ZFS Separate Intent Log

2007-07-09 Thread Neil Perrin
Cyril Plisko wrote: On 7/7/07, Neil Perrin [EMAIL PROTECTED] wrote: Cyril, I wrote this case and implemented the project. My problem was that I didn't know what policy (if any) Sun has about publishing ARC cases, and a mail log with a gazillion email addresses. I did receive an answer

Re: [zfs-discuss] Take Three: PSARC 2007/171 ZFS Separate Intent Log

2007-07-09 Thread Neil Perrin
Er with attachment this time. So I've attached the accepted proposal. There was (as expected) not much discussion of this case as it was considered an obvious extension. The actual psarc case materials when opened will not have much more info than this. PSARC CASE: 2007/171 ZFS Separate Intent

[zfs-discuss] separate intent log blog

2007-07-18 Thread Neil Perrin
I wrote up a blog on the separate intent log called slog blog which describes the interface; some performance results; and general status: http://blogs.sun.com/perrin/entry/slog_blog_or_blogging_on Neil. ___ zfs-discuss mailing list

Re: [zfs-discuss] separate intent log blog

2007-07-18 Thread Neil Perrin
Albert Chin wrote: On Wed, Jul 18, 2007 at 01:29:51PM -0600, Neil Perrin wrote: I wrote up a blog on the separate intent log called slog blog which describes the interface; some performance results; and general status: http://blogs.sun.com/perrin/entry/slog_blog_or_blogging_on So, how

Re: [zfs-discuss] separate intent log blog

2007-07-27 Thread Neil Perrin
Adolf, Yes, there was a separate driver, that I believe came from Micro Memories. I installit from a package umem_Sol_Drv_Cust_i386_v01_10.pkg. I just use pkgadd on it and it just worked. Sorry, I don't know if it's publicly available or will even work for your device. I gave details of that

Re: [zfs-discuss] ZFS, ZIL, vq_max_pending and OSCON

2007-08-07 Thread Neil Perrin
Jay, Slides look good, though I'm not not sure what you say along with Filthy lying on slide 22 related to the ZIL, or slide 27 which has Worst Feature - thinks hardware is stupid. Anyway I have some comments on http://www.meangrape.com/2007/08/oscon-zfs You say: --- Records in the ZIL are

Re: [zfs-discuss] zfs iscsi storage for virtual machines

2007-08-08 Thread Neil Perrin
How does ZFS handle snapshots of large files like VM images? Is replication done on the bit/block level or by file? In otherwords, does a snapshot of a changed VM image take up the same amount of space as the image or only the amount of space of the bits that have changed within the

Re: [zfs-discuss] Serious ZFS problems

2007-09-06 Thread Neil Perrin
Tim Spriggs wrote: Hello, I think I have gained sufficient fool status for testing the fool-proof-ness of zfs. I have a cluster of T1000 servers running Solaris 10 and two x4100's running an OpenSolaris dist (Nexenta) which is at b68. Each T1000 hosts several zones each of which

Re: [zfs-discuss] Mixing SATA PATA Drives

2007-09-17 Thread Neil Perrin
Yes performance will suffer, but it's a bit difficult to say by how much. Both pool transaction group writes and zil writes are spread across all devices. It depends on what applications you will run as to how much use is made of the zil. Maybe you should experiment and see if performance is good

Re: [zfs-discuss] Zfs log device (zil) ever coming to Sol10?

2007-09-18 Thread Neil Perrin
Separate log devices (slogs) didn't make it into S10U4 but will be in U5. Andy Lubel wrote: I think we are very close to using zfs in our production environment.. Now that I have snv_72 installed and my pools set up with NVRAM log devices things are hauling butt. I've been digging to find

Re: [zfs-discuss] Zfs log device (zil) ever coming to Sol10?

2007-09-18 Thread Neil Perrin
Matty wrote: On 9/18/07, Neil Perrin [EMAIL PROTECTED] wrote: Separate log devices (slogs) didn't make it into S10U4 but will be in U5. This is awesome! Will the SYNC_NV support that was integrated this week be added to update 5 as well? That would be super useful, assuming the major

Re: [zfs-discuss] enlarge a mirrored pool

2007-10-12 Thread Neil Perrin
Erik Trimble wrote: Ivan Wang wrote: Hi all, Forgive me if this is a dumb question. Is it possible for a two-disk mirrored zpool to be seamlessly enlarged by gradually replacing previous disk with larger one? Say, in a constrained desktop, only space for two internal disks is

Re: [zfs-discuss] characterizing I/O on a per zvol basis.

2007-10-18 Thread Neil Perrin
I don't know of any way to observe IOPS per zvol and I believe this would be tricky. Any writes/reads from individual datasets (filesystems and zvols) will go through the pipeline and can fan out to multiple mirrors or raidz or be striped across devices. Block writes will be combined and pushed

Re: [zfs-discuss] ZIL reliability/replication questions

2007-10-18 Thread Neil Perrin
Scott Laird wrote: I'm debating using an external intent log on a new box that I'm about to start working on, and I have a few questions. 1. If I use an external log initially and decide that it was a mistake, is there a way to move back to the internal log without rebuilding the entire

Re: [zfs-discuss] ZIL reliability/replication questions

2007-10-18 Thread Neil Perrin
Scott Laird wrote: On 10/18/07, Neil Perrin [EMAIL PROTECTED] wrote: Scott Laird wrote: I'm debating using an external intent log on a new box that I'm about to start working on, and I have a few questions. 1. If I use an external log initially and decide that it was a mistake

Re: [zfs-discuss] ZIL reliability/replication questions

2007-10-18 Thread Neil Perrin
Scott Laird wrote: On 10/18/07, Neil Perrin [EMAIL PROTECTED] wrote: So, the only way to lose transactions would be a crash or power loss, leaving outstanding transactions in the log, followed by the log device failing to start up on reboot? I assume that that would that be handled

Re: [zfs-discuss] slog tests on read throughput exhaustion (NFS)

2007-11-16 Thread Neil Perrin
Joe, I don't think adding a slog helped in this case. In fact I believe it made performance worse. Previously the ZIL would be spread out over all devices but now all synchronous traffic is directed at one device (and everything is synchronous in NFS). Mind you 15MB/s seems a bit on the slow

Re: [zfs-discuss] slog tests on read throughput exhaustion (NFS)

2007-11-19 Thread Neil Perrin
Roch - PAE wrote: Neil Perrin writes: Joe Little wrote: On Nov 16, 2007 9:13 PM, Neil Perrin [EMAIL PROTECTED] wrote: Joe, I don't think adding a slog helped in this case. In fact I believe it made performance worse. Previously the ZIL would be spread out over

Re: [zfs-discuss] ZFS write frequency

2007-11-28 Thread Neil Perrin
Ajay Kumar wrote: IHAC who would like to understand following: We've upgraded a box to sol10-u4 and created a ZFS pool. We notice that running zfs iostat 1 or iostat -xnz 1, the data gets written to disk every 5 seconds, even though the data is being copied to the filesystem

Re: [zfs-discuss] Bugid 6535160

2007-12-14 Thread Neil Perrin
Vincent Fox wrote: So does anyone have any insight on BugID 6535160? We have verified on a similar system, that ZFS shows big latency in filebench varmail test. We formatted the same LUN with UFS and latency went down from 300 ms to 1-2 ms. This is such a big difference it makes me

Re: [zfs-discuss] Bugid 6535160

2007-12-14 Thread Neil Perrin
Vincent Fox wrote: So does anyone have any insight on BugID 6535160? We have verified on a similar system, that ZFS shows big latency in filebench varmail test. We formatted the same LUN with UFS and latency went down from 300 ms to 1-2 ms. This is such a big difference it makes me think

Re: [zfs-discuss] copy on write related query

2008-01-06 Thread Neil Perrin
sudarshan sridhar wrote: I'm not quite sure what you're asking here. Data, whether newly written or copy-on-write, goes to a newly allocated block, which may reside on any vdev, and will be spread across devices if using RAID. My exact doubt is, if COW is default behavior of ZFS then does

Re: [zfs-discuss] Intent logs vs Journaling

2008-01-07 Thread Neil Perrin
parvez shaikh wrote: Hello, I am learning ZFS, its design and layout. I would like to understand how Intent logs are different from journal? Journal too are logs of updates to ensure consistency of file system over crashes. Purpose of intent log also appear to be same. I hope I am

Re: [zfs-discuss] ZFS behavior with fsync() calls

2008-01-11 Thread Neil Perrin
Todd Moore wrote: My understanding is that the answers to the questions posed below are both YES due the transactional design of ZFS. However, I'm working with some folks that need more details or documents describing the design/behavior without having to look through all the source

Re: [zfs-discuss] NFS performance on ZFS vs UFS

2008-01-24 Thread Neil Perrin
Steve Hillman wrote: I realize that this topic has been fairly well beaten to death on this forum, but I've also read numerous comments from ZFS developers that they'd like to hear about significantly different performance numbers of ZFS vs UFS for NFS-exported filesystems, so here's one

Re: [zfs-discuss] ZIL controls in Solaris 10 U4?

2008-01-30 Thread Neil Perrin
Roch - PAE wrote: Jonathan Loran writes: Is it true that Solaris 10 u4 does not have any of the nice ZIL controls that exist in the various recent Open Solaris flavors? I would like to move my ZIL to solid state storage, but I fear I can't do it until I have another update.

Re: [zfs-discuss] ZIL controls in Solaris 10 U4?

2008-01-30 Thread Neil Perrin
Jonathan Loran wrote: Vincent Fox wrote: Are you already running with zfs_nocacheflush=1? We have SAN arrays with dual battery-backed controllers for the cache, so we definitely have this set on all our production systems. It makes a big difference for us. No, we're not using the

Re: [zfs-discuss] ZFS Performance Issue

2008-02-06 Thread Neil Perrin
Marc Bevand wrote: William Fretts-Saxton william.fretts.saxton at sun.com writes: I disabled file prefetch and there was no effect. Here are some performance numbers. Note that, when the application server used a ZFS file system to save its data, the transaction took TWICE as long. For

Re: [zfs-discuss] 100% random writes coming out as 50/50 reads/writes

2008-02-15 Thread Neil Perrin
Nathan Kroenert wrote: And something I was told only recently - It makes a difference if you created the file *before* you set the recordsize property. If you created them after, then no worries, but if I understand correctly, if the *file* was created with 128K recordsize, then it'll

Re: [zfs-discuss] ZFS and multipath with iSCSI

2008-04-04 Thread Neil Perrin
ZFS will handle out of order writes due to it transactional nature. Individual writes can be re-ordered safely. When the transaction commits it will wait for all writes and flush them; then write a new uberblock with the new transaction group number and flush that. Chris Siebenmann wrote: We're

Re: [zfs-discuss] incorrect/conflicting suggestion in error message on a faulted pool

2008-04-09 Thread Neil Perrin
Haudy, Thanks for reporting this bug and helping to improve ZFS. I'm not sure either how you could have added a note to an existing report. Anyway I've gone ahead and done that for you in the Related Bugs field. Though opensolaris doesn't reflect it yet Neil. Haudy Kazemi wrote: I have

Re: [zfs-discuss] Pause Solaris with ZFS compression busy by doing a cp?

2008-05-22 Thread Neil Perrin
I also noticed (perhaps by design) that a copy with compression off almost instantly returns, but the writes continue LONG after the cp process claims to be done. Is this normal? Yes this is normal. Unless the application is doing synchronous writes (eg DB) the file will be written to disk at

Re: [zfs-discuss] ZFS in S10U6 vs openSolaris 05/08

2008-05-24 Thread Neil Perrin
Hugh Saunders wrote: On Sat, May 24, 2008 at 4:00 PM, [EMAIL PROTECTED] wrote: cache improve write performance or only reads? L2ARC cache device is for reads... for write you want Intent Log Thanks for answering my question, I had seen mention of intent log devices, but wasn't sure

Re: [zfs-discuss] slog devices don't resilver correctly

2008-05-27 Thread Neil Perrin
Joe Little wrote: On Tue, May 27, 2008 at 4:50 PM, Eric Schrock [EMAIL PROTECTED] wrote: Joe - We definitely don't do great accounting of the 'vdev_islog' state here, and it's possible to create a situation where the parent replacing vdev has the state set but the children do not, but I have

Re: [zfs-discuss] RFE 4852783

2008-06-16 Thread Neil Perrin
This is actually quite a tricky fix as obviously data and meta data have to be relocated. Although there's been no visible activity in this bug there has been substantial design activity to allow the RFE to be easily fixed. Anyway, to answer your question, I would fully expect this RFE would be

Re: [zfs-discuss] ZFS and Caching - write() syscall with O_SYNC

2008-07-07 Thread Neil Perrin
Patrick Pinchera wrote: IHAC using ZFS in production, and he's opening up some files with the O_SYNC flag. This affects subsequent write()'s by providing synchronized I/O file integrity completion. That is, each write(2) will wait for both the file data and file status to be physically

Re: [zfs-discuss] ZFS deduplication

2008-07-07 Thread Neil Perrin
Mertol, Yes, dedup is certainly on our list and has been actively discussed recently, so there's hope and some forward progress. It would be interesting to see where it fits into our customers priorities for ZFS. We have a long laundry list of projects. In addition there's bug fixes performance

Re: [zfs-discuss] zfs-discuss Digest, Vol 33, Issue 19

2008-07-08 Thread Neil Perrin
them up. I'm still waiting for the hardware for this server, but regarding the drivers, if these cards don't work out of the box I was planning to pester Neil Perrin and see if he still has some drivers for them :) Unfortunately, there are a couple of problems: 1. It's been a while

Re: [zfs-discuss] Supermicro AOC-SAT2-MV8 hang when drive removed

2008-07-30 Thread Neil Perrin
Peter Cudhea wrote: Your point is well taken that ZFS should not duplicate functionality that is already or should be available at the device driver level.In this case, I think it misses the point of what ZFS should be doing that it is not. ZFS does its own periodic commits to the

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