similar to: A couple of newbie questions about ZFS compression

I was wondering if I should add compression support to mdbox one mail at a time or one file (~2MB) at a time. The tradeoffs are: * one mail at a time allows quickly seeking to wanted mail inside the file, but it can't compress mails as well * one file at a time compresses better, but seeking is slow because it can only be done by uncompressing all the data until the wanted offset is reached

Hi, I just installed 2009.06 and found that compression isn''t enabled by default when filesystems are created. Does is make sense to have an RFE open for this? (I''ll open one tonight if need be.) We keep telling people to turn on compression. Are there any situations where turning on compression doesn''t make sense, like rpool/swap? what about rpool/dump? Thanks, ~~sa

Bellow, follows a proposal for a new opensolaris project. Of course, this is open to change since I just wrote down some ideas I had months ago, while researching the topic as a graduate student in Computer Science, and since I''m not an opensolaris/ZFS expert at all. I would really appreciate any suggestion or comments. PROJECT PROPOSAL: ZFS Compression Algorithms. The main purpose of

Hi, use "doveadm" to get all real message doveadm -f table fetch -A "size.physical" ALL | awk '{s+=$2}END{printf("%.2fMB\n", s/1024/1024);}' 189247.67MB .. 185G use "du" to get size on disc: In my case with deduplication: /srv/stroage/# du -s -h * 53G vmail 75G vmail_sis without deduplication /srv/stroage/# du -s -h -l * 53G

Adam, With the blog entry[1] you''ve made about gzip for ZFS, it raises a couple of questions... 1) It would appear that a ZFS filesystem can support files of varying compression algorithm. If a file is compressed using method A but method B is now active, if I truncate the file and rewrite it, is A or B used? 2) The question of whether or not to use bzip2 was raised in the

Hello. I want to know what is the unit of compression in ZFS. Is it 4 KB or larger? Is it tunnable? Thanks. Thanos -- This message posted from opensolaris.org

Is there a mechanism by which you can perform a zfs send | zfs receive and not have the data uncompressed and recompressed at the other end? I have a gzip-9 compressed filesystem that I want to backup to a remote system and would prefer not to have to recompress everything again at such great computation expense. If this doesn''t exist, how would one go about creating an RFE for

Hi - there's a flag for rsync to compress the files in transit - is it possible to compress one side (target) with gzip and have rsync still work correctly? Any help would be appreciated. -- Ken

I''ve noticed that: - with x86-64 Fedora 15 DVD install images: - du -sh <ROOT VOLUME> was 36 GB - btrfs df | grep -i data have shown over 40 GB used - without - du -sh <ROOT VOLUME> is 34 GB - btrfs df | grep -i data have shown less then 34 GB used It seems that iso files are considered compressable while they may not be (and penalty is severe - 3x). Regards

Hi! I''d been scouring the forums and web for admins/users who deployed zfs with compression enabled on Oracle backed by storage array luns. Any problems with cpu/memory overhead? -- This message posted from opensolaris.org

> From: zfs-discuss-bounces at opensolaris.org [mailto:zfs-discuss- > bounces at opensolaris.org] On Behalf Of bob netherton > > You can, with recv, override any property in the sending stream that can > be > set from the command line (ie, a writable). > > # zfs send repo/support at cpu-0412 | zfs recv -o version=4 repo/test > cannot receive: cannot override received

Some miscellaneous questions: * When you share a ZFS fs via NFS, what happens to files and filesystems that exceed the limits of NFS? * Is there a recommendation or some guidelines to help answer the question "how full should a pool be before deciding it''s time add disk space to a pool?" * Migrating pre-ZFS backups to ZFS backups: is there a better method than "restore

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

Hi, I don''t know if this has been discussed before, but have you thought about adding LZO compression to ZFS? One zfs-fuse user has provided a patch which implements LZO compression, and he claims better compression ratios *and* better speed than lzjb. The miniLZO library is licensed under the GPL, but the author specifically says that other licenses are available by request. Has this

Hello, ZFS is behaving strange on a OSOL laptop, your thoughts are welcome. I am running OSOL on my laptop, currently b124 and i found that the performance of ZFS is not optimal in all situations. If i check the how much space the package cache for pkg(1) uses, it takes a bit longer on this host than on comparable machine to which i transferred all the data. user at host:/var/pkg$ time

[Sol 10 6/6 x64] I am very newbie in ZFS. I have created 30GB storage pool and become a root_pool. If I run "du -hs" from root directory , it reports only used 5.4G. But when I run "df -h", it reports used 26G. Why it is happens? How to reclaim back to 5.4G usage? Thanks, Regards -- This messages posted from opensolaris.org

Hello, I''m currently trying to understand how compression in btrfs works. I could not find any detailed description about it. So here are my questions. 1. How is decided what to compress and what not? After a fast test with a 2g image file, I''ve looked into the extents of that file with find-new and it turned out that only some of the first extents were compressed. The file was

When using compression, are the on-disk record sizes determined before or after compression is applied? In other words, if record size is set to 128k, is that the amount of data fed into the compression engine, or is the output size trimmed to fit? I think it''s the former, but I''m not certain. This could affect block alignment for SSDs, leading to worse write performance. It

Hi, may be someone has already done that: Do you have a script(?) tool which shows the efficiency of the mail compression if zlib is used? Something that shows the uncompressed size vrs. the compressed. Thanks for hints! /G?tz -------------- next part -------------- A non-text attachment was scrubbed... Name: smime.p7s Type: application/pkcs7-signature Size: 5571 bytes Desc: S/MIME

I am [trying to] perform a test prior to moving my data to solaris and zfs. Things are going very poorly. Please suggest what I might do to understand what is going on, report a meaningful bug report, fix it, whatever! Both to learn what the compression could be, and to induce a heavy load to expose issues, I am running with compress=gzip-9. I have two machines, both identical 800MHz P3 with