search for: zfs_nocacheflush

A question regarding zfs_nocacheflush: The Evil Tuning Guide says to only enable this if every device is protected by NVRAM. However, is it safe to enable zfs_nocacheflush when I also have local drives (the internal system drives) using ZFS, in particular if the write cache is disabled on those drives? What I have is a local zfs poo...

Hi, I''m running SunOS Release 5.10 Version Generic_118855-36 64-bit and in [b]/etc/system[/b] I put: [b]set zfs:zfs_nocacheflush = 1[/b] And after rebooting, I get the message: [b]sorry, variable ''zfs_nocacheflush'' is not defined in the ''zfs'' module[/b] So is this variable not available in the Solaris kernel? I''m getting really poor write performance with ZFS on a RAID5 volum...

...well-known behaviour of ZFS is that it often issues cache flush commands to storage in order to ensure data integrity; while this is important with normal disks, it''s useless for nvram write caches, and it effectively disables the cache. so far, i''ve worked around this by setting zfs_nocacheflush, as described at [1], which works fine. but now i want to upgrade this system to Solaris 10 Update 6, and use a ZFS root pool on its internal SCSI disks (previously, the root was UFS). the problem is that zfS_nocacheflush applies to all pools, which will include the root pool. my understanding o...

Nicolas Dorfsman wrote: > Le 27 nov. 07 ? 16:17, Torrey McMahon a ?crit : > >> According to the array vendor the 99xx arrays no-op the cache flush >> command. No need to set the /etc/system flag. >> >> http://blogs.sun.com/torrey/entry/zfs_and_99xx_storage_arrays >> >> > > > Perfect ! > > Thanks Torrey. > > Just realize

Hi, I read some articles on solarisinternals.com like "ZFS_Evil_Tuning_Guide" on http://www.solarisinternals.com/wiki/index.php/ZFS_Evil_Tuning_Guide . They clearly suggest to disable cache flush http://www.solarisinternals.com/wiki/index.php/ZFS_Evil_Tuning_Guide#FLUSH . It seems to be the only serious article on the net about this subject. Could someone here state on this

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. Heck, I would be happy to just be able to turn the ZIL off to see how my NFS on ZFS performance is effected before spending the $''s. Anyone

...sion... http://www.opensolaris.org/jive/thread.jspa?messageID=143517 ...we never found out how (or if) the Sun 6120 (T4) array can be configured to ignore cache flush (sync-cache) requests from hosts. We''re about to reconfigure a 6120 here for use with ZFS (S10U4), and the evil tuneable zfs_nocacheflush is not going to serve us well (there is a ZFS pool on slices of internal SAS drives, along with UFS boot/OS slices). Any pointers would be appreciated. Thanks and regards, Marion

I''m running Postgresql (v8.1.10) on Solaris 10 (Sparc) from within a non-global zone. I originally had the database "storage" in the non-global zone (e.g. /var/local/pgsql/data on a UFS filesystem) and was getting performance of "X" (e.g. from a TPC-like application: http://www.tpc.org). I then wanted to try relocating the database storage from the zone (UFS

This may not be a ZFS issue, so please bear with me! I have 4 internal drives that I have striped/mirrored with ZFS and have an application server which is reading/writing to hundreds of thousands of files on it, thousands of files @ a time. If 1 client uses the app server, the transaction (reading/writing to ~80 files) takes about 200 ms. If I have about 80 clients attempting it @ once, it can

We''re using some X4540s, with OpenSolaris 2008.11. According to my testing, to optimize our systems for our specific workload, I''ve determined that we get the best performance with the write cache disabled on every disk, and with zfs:zfs_nocacheflush=1 set in /etc/system. The only issue is setting the write cache permanently, or at least quickly. Right now, as it is, I''ve scripted up format to run on boot, disabling the write cache of all disks. This takes around two minutes. I''d like to avoid needing to take this time on...

Hi all, yesterday we had a drive failure on a fc-al jbod with 14 drives. Suddenly the zpool using that jbod stopped to respond to I/O requests and we get tons of the following messages on /var/adm/messages: Sep 3 15:20:10 fb2 scsi: [ID 107833 kern.warning] WARNING: /scsi_vhci/disk at g20000004cfd81b9f (sd52): Sep 3 15:20:10 fb2 SCSI transport failed: reason ''timeout'':

I have a lot of people whispering "zfs" in my virtual ear these days, and at the same time I have an irrational attachment to xfs based entirely on its lack of the 32000 subdirectory limit. I''m not afraid of ext4''s newness, since really a lot of that stuff has been in Lustre for years. So a-benchmarking I went. Results at the bottom:

I''m new so opensolaris and very new to ZFS. In the past we have always used linux for our database backends. So now we are looking for a new database server to give us a big performance boost, and also the possibility for scalability. Our current database consists mainly of a huge table containing about 230 million records and a few (relatively) smaller tables (something like 13 million

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