similar to: Bursty writes - why?

Displaying 20 results from an estimated 1000 matches similar to: "Bursty writes - why?"

2010 Jan 13
28
New ZFS Intent Log (ZIL) device available - Beta program now open!
The DDRdrive X1 OpenSolaris device driver is now complete, please join us in our first-ever ZFS Intent Log (ZIL) beta test program. A select number of X1s are available for loan, preferred candidates would have a validation background and/or a true passion for torturing new hardware/driver :-) We are singularly focused on the ZIL device market, so a test environment bound by synchronous writes
2010 May 24
16
questions about zil
I recently got a new SSD (ocz vertex LE 50gb) It seems to work really well as a ZIL performance wise. My question is, how safe is it? I know it doesn''t have a supercap so lets'' say dataloss occurs....is it just dataloss or is it pool loss? also, does the fact that i have a UPS matter? the numbers i''m seeing are really nice....these are some nfs tar times before
2009 Apr 11
17
Supermicro SAS/SATA controllers?
The standard controller that has been recommended in the past is the AOC-SAT2-MV8 - an 8 port with a marvel chipset. There have been several mentions of LSI based controllers on the mailing lists and I''m wondering about them. One obvious difference is that the Marvel contoller is PCI-X and the LSI controllers are PCI-E. Supermicro have several LSI controllers. AOC-USASLP-L8i with the
2010 Oct 08
74
Performance issues with iSCSI under Linux
Hi!We''re trying to pinpoint our performance issues and we could use all the help to community can provide. We''re running the latest version of Nexenta on a pretty powerful machine (4x Xeon 7550, 256GB RAM, 12x 100GB Samsung SSDs for the cache, 50GB Samsung SSD for the ZIL, 10GbE on a dedicated switch, 11x pairs of 15K HDDs for the pool). We''re connecting a single Linux
2011 Mar 01
14
Good SLOG devices?
Hi I''m running OpenSolaris 148 on a few boxes, and newer boxes are getting installed as we speak. What would you suggest for a good SLOG device? It seems some new PCI-E-based ones are hitting the market, but will those require special drivers? Cost is obviously alsoo an issue here.... Vennlige hilsener / Best regards roy -- Roy Sigurd Karlsbakk (+47) 97542685 roy at karlsbakk.net
2010 Jul 21
5
L2ARC and ZIL on same SSD?
Are there any drawbacks to partition a SSD in two parts and use L2ARC on one partition, and ZIL on the other? Any thoughts? -- This message posted from opensolaris.org
2011 Jan 29
27
ZFS and TRIM
My google-fu is coming up short on this one... I didn''t see that it had been discussed in a while ... What is the status of ZFS support for TRIM? For the pool in general... and... Specifically for the slog and/or cache??? -------------- next part -------------- An HTML attachment was scrubbed... URL:
2010 Jun 25
13
OCZ Vertex 2 Pro performance numbers
Now the test for the Vertex 2 Pro. This was fun. For more explanation please see the thread "Crucial RealSSD C300 and cache flush?" This time I made sure the device is attached via 3GBit SATA. This is also only a short test. I''ll retest after some weeks of usage. cache enabled, 32 buffers, 64k blocks linear write, random data: 96 MB/s linear read, random data: 206 MB/s linear
2010 May 26
14
creating a fast ZIL device for $200
Recently, I''ve been reading through the ZIL/slog discussion and have the impression that a lot of folks here are (like me) interested in getting a viable solution for a cheap, fast and reliable ZIL device. I think I can provide such a solution for about $200, but it involves a lot of development work. The basic idea: the main problem when using a HDD as a ZIL device are the cache flushes
2010 Dec 23
31
SAS/short stroking vs. SSDs for ZIL
Hi, as I have learned from the discussion about which SSD to use as ZIL drives, I stumbled across this article, that discusses short stroking for increasing IOPs on SAS and SATA drives: http://www.tomshardware.com/reviews/short-stroking-hdd,2157.html Now, I am wondering if using a mirror of such 15k SAS drives would be a good-enough fit for a ZIL on a zpool that is mainly used for file
2010 Aug 12
6
one ZIL SLOG per zpool?
I have three zpools on a server and want to add a mirrored pair of ssd''s for the ZIL. Can the same pair of SSDs be used for the ZIL of all three zpools or is it one ZIL SLOG device per zpool? -- This message posted from opensolaris.org
2010 Jan 02
27
Pool import with failed ZIL device now possible ?
Hello list, someone (actually neil perrin (CC)) mentioned in this thread: http://mail.opensolaris.org/pipermail/zfs-discuss/2009-December/034340.html that is should be possible to import a pool with failed log devices (with or without data loss ?). >/ />/ Has the following error no consequences? />/ />/ Bug ID 6538021 />/ Synopsis Need a way to force pool startup when
2010 Jan 12
11
How do separate ZFS filesystems affect performance?
I''m working with a Cyrus IMAP server running on a T2000 box under Solaris 10 10/09 with current patches. Mailboxes reside on six ZFS filesystems, each containing about 200 gigabytes of data. These are part of a single zpool built on four Iscsi devices from our Netapp filer. One of these ZFS filesystems contains a number of global and per-user databases in addition to one sixth of the
2008 Oct 08
1
Shutting down / exporting zpool without flushing slog devices
Hey folks, This might be a daft idea, but is there any way to shut down solaris / zfs without flushing the slog device? The reason I ask is that we''re planning to use mirrored nvram slogs, and in the long term hope to use a pair of 80GB ioDrives. I''d like to have a large amount of that reserved for write cache (potentially 20-30GB), to facilitate rapid suspend to disk of
2011 Jul 15
22
Zil on multiple usb keys
This might be a stupid question, but here goes... Would adding, say, 4 4 or 8gb usb keys as a zil make enough of a difference for writes on an iscsi shared vol? I am finding reads are not too bad (40is mb/s over gige on 2 500gb drives stripped) but writes top out at about 10 and drop a lot lower... If I where to add a couple usb keys for zil, would it make a difference? Thanks. Sent from a
2011 Jul 30
7
NexentaCore 3.1 - ZFS V. 28
apt-get update apt-clone upgrade Any first impressions? -- Eugen* Leitl <a href="http://leitl.org">leitl</a> http://leitl.org ______________________________________________________________ ICBM: 48.07100, 11.36820 http://www.ativel.com http://postbiota.org 8B29F6BE: 099D 78BA 2FD3 B014 B08A 7779 75B0 2443 8B29 F6BE
2007 Nov 17
11
slog tests on read throughput exhaustion (NFS)
I have historically noticed that in ZFS, when ever there is a heavy writer to a pool via NFS, the reads can held back (basically paused). An example is a RAID10 pool of 6 disks, whereby a directory of files including some large 100+MB in size being written can cause other clients over NFS to pause for seconds (5-30 or so). This on B70 bits. I''ve gotten used to this behavior over NFS, but
2010 Jun 19
6
does sharing an SSD as slog and l2arc reduces its life span?
Hi, I don''t know if it''s already been discussed here, but while thinking about using the OCZ Vertex 2 Pro SSD (which according to spec page has supercaps built in) as a shared slog and L2ARC device it stroke me that this might not be a such a good idea. Because this SSD is MLC based, write cycles are an issue here, though I can''t find any number in their spec. Why do I
2010 Jul 21
5
slog/L2ARC on a hard drive and not SSD?
Hi, Out of pure curiosity, I was wondering, what would happen if one tries to use a regular 7200RPM (or 10K) drive as slog or L2ARC (or both)? I know these are designed with SSDs in mind, and I know it''s possible to use anything you want as cache. So would ZFS benefit from it? Would it be the same? Would it slow down? I guess it would slow things down, because it would be trying to
2010 Apr 10
21
What happens when unmirrored ZIL log device is removed ungracefully
Due to recent experiences, and discussion on this list, my colleague and I performed some tests: Using solaris 10, fully upgraded. (zpool 15 is latest, which does not have log device removal that was introduced in zpool 19) In any way possible, you lose an unmirrored log device, and the OS will crash, and the whole zpool is permanently gone, even after reboots. Using opensolaris,