Re: [zfs-discuss] OCZ RevoDrive ZFS support
What kind of testing did you do on the Samsung SSD? I've used FusionIO cards to get upwards of 500MB/s writes and OCZ Deneva SSD (SATA) drives to get 200-250MB/s writes. In many cases the trick is to make sure you have a sufficient amount of threads doing writes in order to get optimal performance. Or it could just be that the Samsung drive you tested has something seriously wrong with it. -Moazam On Nov 26, 2010 8:40pm, Edward Ned Harvey wrote: > From: zfs-discuss-boun...@opensolaris.org [mailto:zfs-discuss- > boun...@opensolaris.org] On Behalf Of Karel Gardas > > Thank you Christopher and Edward for all the detailed information provided. > Indeed DDRDrive looks like a right tool for fast ZIL, but for my development > workstation I'm rather searching for l2arc cache where as you note ReviDrive > might do the nice job. Be sure to test the performance of the device when/if you get it. A lot of SSD's out there don't perform any better than spindle drives. In fact, I recently got one of these Samsung drives... http://tinyurl.com/38s3ac3 The spec sheet says sequential read 220MB/s, sequential write 120MB/s... Which is 2-4 times faster than the best SATA disk out there... And of course, negligible seek time and latency ... But in practice, I find that drive is no faster than my cheap 500G sata disk. Or maybe just barely faster. Not much. You can't go wrong by adding more RAM. Until you hit the price barrier. Before you start building l2arc. ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] OCZ RevoDrive ZFS support
> From: zfs-discuss-boun...@opensolaris.org [mailto:zfs-discuss- > boun...@opensolaris.org] On Behalf Of Karel Gardas > > Thank you Christopher and Edward for all the detailed information provided. > Indeed DDRDrive looks like a right tool for fast ZIL, but for my development > workstation I'm rather searching for l2arc cache where as you note ReviDrive > might do the nice job. Be sure to test the performance of the device when/if you get it. A lot of SSD's out there don't perform any better than spindle drives. In fact, I recently got one of these Samsung drives... http://tinyurl.com/38s3ac3 The spec sheet says sequential read 220MB/s, sequential write 120MB/s... Which is 2-4 times faster than the best SATA disk out there... And of course, negligible seek time and latency ... But in practice, I find that drive is no faster than my cheap 500G sata disk. Or maybe just barely faster. Not much. You can't go wrong by adding more RAM. Until you hit the price barrier. Before you start building l2arc. ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] ashift and vdevs
On Tue, Nov 23, 2010 at 9:55 AM, Krunal Desai wrote: > What is the "upgrade path" like from this? For example, currently I The ashift is set in the pool when it's created and will persist through the life of that pool. If you set it at pool creation, it will stay regardless of OS upgrades. -B -- Brandon High : bh...@freaks.com ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] ashift and vdevs
On Nov 26, 2010, at 20:09 , taemun wrote: > If you consider that for a 4KB internal drive, with a 512B external > interface, a request for a 512B write will result in the drive reading 4KB, > modifying it (putting the new 512B in) and then writing the 4KB out again. > This is terrible from a latency perspective. I recall seeing 20 IOPS on a WD > EARS 2TB drive (ie, 50ms latency for random 512B writes). Agreed. However, if you look at this MS KB article: http://support.microsoft.com/kb/982018/en-us , Windows 7 (even with SP1) has no support for 4K-sector drives. Obviously, we're dealing with ZFS and Solaris/BSD here, but what I'm getting at is, which 4K sector drives offer a jumper or other method to completely disable any form of emulation and appear to the host OS as a 4K-sector drive? I believe the Barracuda LPs (the 5900rpm) disks can do this, but I'm not sure about the others like the F4s. I believe you earlier said you were using F4s (the HD204UIs) and the 5900rpm Seagates; can you explicate further about these drives and their emulation (or lack thereof), I'd appreciate it! --khd ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] ashift and vdevs
On 27 November 2010 08:05, Krunal Desai wrote: > One new thought occurred to me; I know some of the 4K drives emulate 512 > byte sectors, so to the host OS, they appear to be no different than other > 512b drives. With this additional layer of emulation, I would assume that > ashift wouldn't be needed, though I have read reports of this affecting > performance. I think I'll need to confirm what drives do what exactly and > then decide on an ashift if needed. > If you consider that for a 4KB internal drive, with a 512B external interface, a request for a 512B write will result in the drive reading 4KB, modifying it (putting the new 512B in) and then writing the 4KB out again. This is terrible from a latency perspective. I recall seeing 20 IOPS on a WD EARS 2TB drive (ie, 50ms latency for random 512B writes). ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Ext. UPS-backed SATA SSD ZIL?
> What about powering the X25-E by an external power source, one that is also > solid-state and backed by a UPS? In my experience, smaller power supplies > tend to be much more reliable than typical ATX supplies. I don't think the different PSU would be an issue, The supply you've linked doesn't seem to care about linking grounds together. > or even more reliable would be a PicoPSU w/ a hack to make sure that the > power is always on. > > Has anyone tried something like this? Powering ZILs using a second, more > reliable PSU? Thoughts? I hacked up a PicoPSU for robotics use (running off +24V and providing +5/+3.3); your "always-on" should be as easy as shorting the green-black wires (short Pin 14 to ground) with a little solder jumper. But wouldn't you need some type of reset trigger for when the system is reset? Or is that performed by the SATA controller? ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] ashift and vdevs
> I'd also note that in the future at some point, we won't be able to purchase > 512B drives any more. In particular, I think that 3TB drives will all be 4KB > formatted. So it isn't inadvisable for a pool that you plan on expanding to > have ashift=12 (imo). One new thought occurred to me; I know some of the 4K drives emulate 512 byte sectors, so to the host OS, they appear to be no different than other 512b drives. With this additional layer of emulation, I would assume that ashift wouldn't be needed, though I have read reports of this affecting performance. I think I'll need to confirm what drives do what exactly and then decide on an ashift if needed. ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
[zfs-discuss] Ext. UPS-backed SATA SSD ZIL?
Hi all, I've run into the classic NFS performance bottleneck when the ZIL is enabled and having no fast, dedicated ZIL device. Being on a budget I concluded that an X25-E would be my best option, but there is still the concern that its write cache is not battery-backed and that a corrupt ZIL is a big problem. The server's power supply is backed by a UPS, but of course the PSU could just burn out. (I am also considering ACARD but don't yet have total confidence in its' reliability) What about powering the X25-E by an external power source, one that is also solid-state and backed by a UPS? In my experience, smaller power supplies tend to be much more reliable than typical ATX supplies. For example, something like this- http://www.addonics.com/products/power_adapter/aasaps.asp or even more reliable would be a PicoPSU w/ a hack to make sure that the power is always on. Has anyone tried something like this? Powering ZILs using a second, more reliable PSU? Thoughts? Thanks, -- 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] OCZ RevoDrive ZFS support
Thank you Christopher and Edward for all the detailed information provided. Indeed DDRDrive looks like a right tool for fast ZIL, but for my development workstation I'm rather searching for l2arc cache where as you note ReviDrive might do the nice job. Thanks, Karel -- 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] zpool lockup and dedupratio meanings
> I've previously posted about some lockups I've experienced with ZFS. > > There were two suspected causes at the time: one was deduplication, and one > was the 2009.06 code we were running. After upgrading the zpools and adding some more disks to the pool I initiated a zpool scrub and was rewarded with an immediate zfs lockup. I switched to my backup head, killed and restarted the scrub and poof- lockup. Anyone have any ideas why a scrub would lockup my pool? The system itself, and the root pool have no problems. The lockup occurs whether I try to write directly to the pool from the system or to the pool via comstar. -- 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] Recover data from detached ZFS mirror
On Thu, Nov 25, 2010 at 12:45:16AM -0800, maciej kaminski wrote: > I've detached disk from a mirrored zpool using "zpool detach" (not "zpool > split") command. Is it possible to recover data from that disk? If yes, how? > (and how to make it bootable) Take a look at this thread: http://www.mail-archive.com/zfs-discuss@opensolaris.org/msg15620.html Jeff Bonwick provided a tool to recover ZFS label, which will allow to import such detached vdev. -- Pawel Jakub Dawidek http://www.wheelsystems.com p...@freebsd.org http://www.FreeBSD.org FreeBSD committer Am I Evil? Yes, I Am! pgpsKzX4C5hl7.pgp Description: PGP signature ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] zfs on a removable device
> From: zfs-discuss-boun...@opensolaris.org [mailto:zfs-discuss- > boun...@opensolaris.org] On Behalf Of Pavel Heimlich > > I tried to transfer some data between two S11 machines via a usb harddrive > with zfs on it, but importing the zpool failed (with some assertion error I did > not write down) because I did not export it first (on the first machine). I had > to go back to the first machine, plug the drive in again and export the fs. You should not need to go back to the first machine. If you read the error message more closely, I think you'll see it says "use -f" or "use -F" to force import. ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] zfs on a removable device
> From: zfs-discuss-boun...@opensolaris.org [mailto:zfs-discuss- > boun...@opensolaris.org] On Behalf Of Pavel Heimlich > > Are there some zfs / OS parameters I could set so that my usb drive with zfs > on it would meet the expectations one has from a removable drive? (i.e. safe > to remove +-anytime) There is no filesystem, in any OS, which is "safe to remove" at any time. Even when a filesystem is idle, let's take for example, NTFS on a USB thumb drive... The next time it's connected, the OS knows and recognizes that it was ejected unsafely. But since there wasn't any corruption caused, it just silently accepts the drive without complaining. I consider that a flaw in Windows. You should always safely eject any media, on any OS, before yanking it out. If you want to configure ZFS to be more "dumb" and "windows like," ... maybe it's possible somehow, but I doubt it. ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] OCZ RevoDrive ZFS support
> From: zfs-discuss-boun...@opensolaris.org [mailto:zfs-discuss- > boun...@opensolaris.org] On Behalf Of Karel Gardas > > I'm curious if there is a support for OCZ RevoDrive SSD or any other SSD > hooked directly on PCIe in Solaris. This RevoDrive looks particularly > interesting for its low price and why to buy something SATA based when > someone might have twice the speed on PCIe for the same money If you want arc cache, something like the above might be good because it's larger... But if you want log device, I promise you the DDRDrive will kick the butt of any flash device. (In terms of performance.) ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] zfs on a removable device
On Fri, November 26, 2010 08:16, Pavel Heimlich wrote: > Are there some zfs / OS parameters I could set so that my usb drive with > zfs on it would meet the expectations one has from a removable drive? > (i.e. safe to remove +-anytime) Nope. Most file systems on Unix don't have the expectation. You may want to look at the following from zpool(1M): zpool import [-o mntopts] [ -o property=value] ... [-d dir | -c cachefile] [-D] [-f] [-R root] [-F [-n]] -a [...] -f Forces import, even if the pool appears to be poten- tially active. [...] http://docs.sun.com/app/docs/doc/816-5166/zpool-1m As it stands, if you try pulling a drive on any Unix system (ext2, ext3, UFS, FFS, XFS, etc.) the system will generally will not respond kindly. Even with Windows and Mac OS X, it's generally recommended that you "eject" the hardware first in some way. It's just the other file systems are a little less vocal in their objections when you re-insert the device again. Probably the only file system that doesn't worry too much about random ejections is FAT(32). ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] zfs on a removable device
On 26/11/2010 13:16, Pavel Heimlich wrote: I tried to transfer some data between two S11 machines via a usb harddrive with zfs on it, but importing the zpool failed (with some assertion error I did not write down) because I did not export it first (on the first machine). I had to go back to the first machine, plug the drive in again and export the fs. Are there some zfs / OS parameters I could set so that my usb drive with zfs on it would meet the expectations one has from a removable drive? (i.e. safe to remove +-anytime) No you run zpool export first, that is "the OS parameter", this is no different to any other filesystem on any other operating system. If you don't export it first how is Solaris or ZFS supposed to know the difference between you yanking it out because you are purposely moving it and the drive accidentally falling out or some other error that causes it to be come unavailable. Hint: the answer is you can't unless you administratively tell ZFS that the pool is supposed to be going away they way you do that is by 'zpool export'. Unlike other filesystems though ZFS will be consistent on disk. You didn't have to plug it back into to the original system you could have just forced the import. -- Darren J Moffat ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
[zfs-discuss] zfs on a removable device
Hi, I tried to transfer some data between two S11 machines via a usb harddrive with zfs on it, but importing the zpool failed (with some assertion error I did not write down) because I did not export it first (on the first machine). I had to go back to the first machine, plug the drive in again and export the fs. Are there some zfs / OS parameters I could set so that my usb drive with zfs on it would meet the expectations one has from a removable drive? (i.e. safe to remove +-anytime) TIA hajma -- This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
