search for: volblocksize

Hi, I am trying to understand the use of volblocksize in emulated volumes. If I create a volume in pool and I want a database engine to read and write, say 16K blocks. Should I then set volblocksize to 16K ? Regards, Patrik This message posted from opensolaris.org

Dear all, Background: I have a ZFS volume with the incorrect volume blocksize for the filesystem (NTFS) that it is supporting. This volume contains important data that is proving impossible to copy using Windows XP Xen HVM that "owns" the data. The disparity in volume blocksize (current set to 512bytes!!) is causing significant performance problems. Question : Is there a way to

I posted this to the forums a little while ago but I believe the list was split at the time: Does anyone have any recommendations for changing the ZFS volblocksize when creating zfs volumes to serve as VMFS backing stores? I''ve seen several people recommend that the volblocksize be set to 64k in this situation- but without much explanation. What are the advantages and disadvantages to using a 64k size in this case? Any insights are appreciated. T...

Author: eschrock Repository: /hg/zfs-crypto/gate Revision: 8c1e3b54454c3c995f38d9fbb614dfef27d153e9 Log message: 6347421 Trying to set volblocksize on existing volume gives an unexpected error 6347492 snapshots should not pretend to have real properties Files: update: usr/src/common/zfs/zfs_prop.c

...So instead we have opted to do UFS on a zvol using raid-z, in lieu of UFS on SVM using raid5 (we want/need raid protection). This decision was made because of the ease of disk set portability of zpools, and also the [assumed] performance benefit vs SVM. Anyways, I''ve been pondering the volblocksize parameter, and trying to figure out how it interacts with UFS. When the zvol was setup, I took the default 8k size. Since UFS uses an 8k blocksize, this seemed to be a reasonable choice. I''ve been thinking more about it lately, and have also read that UFS will do R/W in bigger than 8k...

I''ve upgraded my system from ufs to zfs (root pool). By default, it creates a zvol for dump and swap. It''s a 4GB Ultra-45 and every late night/morning I run a job which takes around 2GB of memory. With a zvol swap, the system becomes unusable and the Sun Ray client often goes into "26B". So I removed the zvol swap and now I have a standard swap partition. The

...vailable 16240062464 - home1/home1mm01 referenced 14902492672 - home1/home1mm01 compressratio 11.20x - home1/home1mm01 reservation 0 default home1/home1mm01 volsize 161061273600 - home1/home1mm01 volblocksize 16384 - home1/home1mm01 checksum on default home1/home1mm01 compression gzip-1 inherited from home1 home1/home1mm01 readonly off default home1/home1mm01 shareiscsi off def...

List, I have a number of Windows 2016 servers I am deploying, but I’m having some I/O performance issues. I have done all of the obvious things like virtio drivers, but am finding there is more performance to be found with hyper-v extensions, how we virtualize the hardware clock, and iothreads. I’m using ZVOLs to back the VM, and I’m using 4k block sizes, which seems to offer the best 4k random

Hi All, How ZFS volblocksize is related to ZFS record size ? Thanks Manoj Nayak

Hi, My swap is on raidz1. Df -k and swap -l are showing almost no usage of swap, while zfs list and zpool list are showing me 96% capacity. Which should i believe? Justin # df -hk Filesystem size used avail capacity Mounted on /dev/dsk/c3t0d0s1 14G 4.0G 10G 28% / /devices 0K 0K 0K 0% /devices ctfs

....78T - tank/iscsi_luns/vol4 referenced 35.9K - tank/iscsi_luns/vol4 compressratio 1.00x - tank/iscsi_luns/vol4 reservation none default tank/iscsi_luns/vol4 volsize 25G - tank/iscsi_luns/vol4 volblocksize 8K - tank/iscsi_luns/vol4 shareiscsi on inherited from tank/iscsi_luns tank/iscsi_luns/vol4 checksum on default tank/iscsi_luns/vol4 compression off default tank/iscsi_luns/vol4 readonly off...

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

...ws things btrfs-related without any usable mention of zfs/zvol. Could anyone help me interpret the kernel logs, which btrfs-zvol interaction is at fault, so I can pass it on to zfs guys to work on their side as well? Thanks. The test is creating a sparse 100G block device (zfs create -V 100G -s -o volblocksize=4k rpool/vbd/test1), format it (mkfs.btrfs /dev/zvol/rpool/vbd/test1), and mount it. Oops occured, and the mount process stuck. Same thing happens on ubuntu precise''s kernel 3.2 and quantal''s 3.5. What''s interesting is: - if I use ext4 (instead of btrfs) on the zvol, it...

So, what is the story about 4KB disk sectors? Should such disks be avoided with ZFS? Or, no problem? Or, need to modify some config file before usage? -- This message posted from opensolaris.org

Hi all! I am running SXCE 121 on a dual quad-core X2200M2 (64 bit of course). During an installation of a NetBSD 5.0.1 PVM domU, the entire machine crashed with a kernel panic. Here''s what I managed to salvage from the LOM console of the machine: Sep 2 18:55:19 glaurung genunix: /xpvd/xdb@41,51712 (xdb5) offline Sep 2 18:55:19 glaurung genunix: /xpvd/xdb@41,51728 (xdb6) offline

Hello all, After setting up a Solaris 10 machine with ZFS as the new NFS server, I''m stumped by some serious performance problems. Here are the (admittedly long) details (also noted at http://www.netmeister.org/blog/): The machine in question is a dual-amd64 box with 2GB RAM and two broadcom gigabit NICs. The OS is Solaris 10 6/06 and the filesystem consists of a single zpool stripe