similar to: 100% random writes coming out as 50/50 reads/writes

Would it be worthwhile to implement heuristics to auto-tune ''recordsize'', or would that not be worth the effort? -- Regards, Jeremy

Is ZFS efficient at handling huge populations of tiny-to-small files - for example, 20 million TIFF images in a collection, each between 5 and 500k in size? I am asking because I could have sworn that I read somewhere that it isn''t, but I can''t find the reference. Thanks, Brian -- - Brian Gupta http://opensolaris.org/os/project/nycosug/

Hi, I''m preparing a personal TPC-H benchmark. The goal is not to measure or optimize the database performance, but to compare ZFS to UFS in similar configurations. At the moment I''m preparing the tests at home. The test setup is as follows: . Solaris snv_37 . 2 x AMD Opteron 252 . 4 GB RAM . 2 x 80 GB ST380817AS . Oracle 10gR2 (small SGA (320m)) The disks also contain the OS

Hi All, Is there a way to tune the zfs prefetch on a per pool basis? I have a customer that is seeing slow performance on a pool the contains multiple tablespaces from an Oracle database, looking at the LUNs associated to that pool they are constantly at 80% - 100% busy. Looking at the output from arcstat for the miss % on data, prefetch and metadata we are getting around 5 - 10 % on data,

I''ve been seeing read and write performance pathologies with Linux ext3 over iSCSI to zvols, especially with small writes. Does running a journalled filesystem to a zvol turn the block storage into swiss cheese? I am considering serving ext3 journals (and possibly swap too) off a raw, hardware-mirrored device. Before I do (and I''ll write up any results) I''d like to know

A customer has a zpool where their spectral analysis applications create a ton (millions?) of very small files that are typically 1858 bytes in length. They''re using ZFS because UFS consistently runs out of inodes. I''m assuming that ZFS aggregates these little files into recordsize (128K?) blobs for writes. This seems to go reasonably well amazingly enough. Reads are a

Hi Everyone, I perform a snapshot and a zfs send on a filesystem with a recordsize of 16k, and redirect the output to a plain file. Later, I use cat sentfs | zfs receive otherpool/filesystem. In this case the new filesystem''s recordsize will be the default 128k again. The other filesystem attributes (for example atime) are reverted to defaults too. Okay, I can set these later,

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:

Hi All, I am running nevada 79 BFU''ed to 82. The machine is a Ultra 20 with 4GB memory. I have several Windows XP domU''s configured and registered. When ever I try to start the fourth domain I get an out of memory exception: Not enough memory is available, and dom0 cannot be shrunk any further Each of my domains only uses 256 so I thought there would be sufficient memory

[originally reported for ZFS on FreeBSD but Pawel Jakub Dawid says this problem also exists on Solaris hence this email.] Summary: on ZFS, overhead for reading a hole seems far worse than actual reading from a disk. Small buffers are used to make this overhead more visible. I ran the following script on both ZFS and UF2 filesystems. [Note that on FreeBSD cat uses a 4k buffer and md5 uses a 1k

Hello! I''am setup zfs / cifs home storage server, end now have low performance with play movie stored on this zfs from windows client. server hardware is not new , but n windows it perfomance was normal. CPU is AMD Athlon Burton Thunderbird 2500, runing on 1,7GHz, 1024 RAM and storage: usb c4t0d0 ST332062-0A-3.AA-298.09GB /pci at 0,0/pci1458,5004 at 2,2/cdrom at 1/disk at

Hello, I was doing performance testing, validating zvol performance in particularly, and found that zvol write performance to be slow ~35-44MB/s at 1MB blocksize writes. I then tested the underlying zfs file system with the same test and got 121MB/s. Is there any way to fix this? I really would like to have compatible performance between the zfs filesystem and the zfs zvols. # first test is a

Hi, I just said zfs destroy pool/fs, but meant to say zfs destroy pool/junk. Is ''fs'' really gone? thx jake

I have configured a test system with a mirrored rpool and one hot spare. I powered the systems off, pulled one of the disks from rpool to simulate a hardware failure. The hot spare is not activating automatically. Is there something more i should have done to make this work ? pool: rpool state: DEGRADED status: One or more devices could not be opened. Sufficient replicas exist for

Do we have enormous fragmentation here on our X4500 with Solaris 10, ZFS Version 10? What except zfs send/receive can be done to free the fragmented space? One ZFS was used for some month to store some large disk images (each 50GByte large) which are copied there with rsync. This ZFS then reports 6.39TByte usage with zfs list and only 2TByte usage with du. The other ZFS was used for similar

Hello ! Can you please share your experiences with ZFS deployment for Oracle databases for production usage ? Why did you choose to deploy the database on ZFS ? What features of ZFS are you using ? What tuning was done during ZFS setup ? How big are the databases ? Thank you, Jay

Hello All, I am running NTFS over iSCSI on a ZFS ZVOL volume with compression=gzip-9 and blocksize=8K. The server is 2 core P4 3.0 Ghz with 5 GB of RAM. Whenever I start copying files from Windows onto the ZFS disk, after about 100-200 Mb been copied the server starts to experience freezes. I have iostat running, which freezes as well. Even pings on both of the network adapters are reporting

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 I would like to know the blocksize of a particular file. I know the blocksize for a particular file is decided at creation time, in fuction of the write size done and the recordsize property of the dataset. How can I access that information?. Some zdb magic?. - -- Jesus Cea Avion _/_/ _/_/_/ _/_/_/ jcea at

Hello, I have several ~12TB storage servers using Solaris with ZFS. Two of them have recently developed performance issues where the majority of time in an spa_sync() will be spent in the space_map_*() functions. During this time, "zpool iostat" will show 0 writes to disk, while it does hundreds or thousands of small (~3KB) reads each second, presumably reading space map data from

I have a huge problem with ZFS pool fragmentation. I started investigating problem about 2 weeks ago http://www.opensolaris.org/jive/thread.jspa?threadID=34423&tstart=0 I found workaround for now - changing recordsize - but I want better solution. The best solution would be a defragmentator tool, but I can see that it is not easy. When ZFS pool is fragmented then: 1. spa_sync function is