Date: Tue, 17 Apr 2007 07:42:10 -0500 From: Eric Anderson <anderson@centtech.com> To: Pawel Jakub Dawidek <pjd@FreeBSD.org> Cc: "freebsd-fs@freebsd.org" <freebsd-fs@FreeBSD.org> Subject: Re: fsck times/memory sizes/etc Message-ID: <4624C0A2.5010101@centtech.com> In-Reply-To: <20070214233848.GA13680@garage.freebsd.pl> References: <45D321F8.2000808@centtech.com> <20070214233848.GA13680@garage.freebsd.pl>
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On 02/14/07 17:38, Pawel Jakub Dawidek wrote:
> On Wed, Feb 14, 2007 at 08:51:36AM -0600, Eric Anderson wrote:
>> I just did some quick playing around, doing newfs and fsck's on fresh file systems. I did one set on a 1Gb malloc'ed md, and another on a 65GB real disk device. The disk
>> was only being used for this test, nothing else.
>>
>> I don't claim these numbers are perfect, but I did run each test 3-4 times to make sure they were consistent.
>>
>> I found it interesting that the fsck times didn't reduce once all the files/directories were deleted.
>
> This may be because of UFS2 has lazy inodes allocator - it doesn't
> initialize all inode blocks at newfs time, so fsck verifies only
> allocated inode blocks, thus runs faster on new file system.
> When you fill your file system, inode blocks are allocated, but are not
> reclaimed when you delete file/directories.
> You may try the same tests with UFS1, which allocates all inode blocks
> at newfs time.
>
Finally got around to doing this:
##################################################
# newfs -O1 /dev/ad2s2a
/dev/ad2s2a: 65397.4MB (133933888 sectors) block size 16384, fragment
size 2048
using 357 cylinder groups of 183.69MB, 11756 blks, 23552 inodes.
# time fsck -f /dev/ad2s2a
** /dev/ad2s2a
** Last Mounted on
** Phase 1 - Check Blocks and Sizes
** Phase 2 - Check Pathnames
** Phase 3 - Check Connectivity
** Phase 4 - Check Reference Counts
** Phase 5 - Check Cyl groups
2 files, 2 used, 32952243 free (19 frags, 4119028 blocks, 0.0%
fragmentation)
real 0m50.056s
user 0m3.914s
sys 0m0.460s
# memory usage reached max of 7184kb (7MB)
# fill it up
# df -i /mnt
Filesystem 1K-blocks Used Avail Capacity iused ifree %iused
Mounted on
/dev/ad2s2a 65904490 138742 60493390 0% 8408062 0 100% /mnt
# time fsck -f /dev/ad2s2a
** /dev/ad2s2a
** Last Mounted on /mnt
** Phase 1 - Check Blocks and Sizes
** Phase 2 - Check Pathnames
** Phase 3 - Check Connectivity
** Phase 4 - Check Reference Counts
** Phase 5 - Check Cyl groups
8408062 files, 69371 used, 32882874 free (18 frags, 4110357 blocks, 0.0%
fragmentation)
real 1m2.790s
user 0m11.167s
sys 0m0.553s
# memory usage reached max of 39952kb (39MB)
# mount, rm -rf all created files/dirs
# df -i /mnt
Filesystem 1K-blocks Used Avail Capacity iused ifree %iused
Mounted on
/dev/ad2s2a 65904490 6 60632126 0% 2 8408060 0% /mnt
# time fsck -f /dev/ad2s2a
** /dev/ad2s2a
** Last Mounted on /mnt
** Phase 1 - Check Blocks and Sizes
** Phase 2 - Check Pathnames
** Phase 3 - Check Connectivity
** Phase 4 - Check Reference Counts
** Phase 5 - Check Cyl groups
2 files, 3 used, 32952242 free (18 frags, 4119028 blocks, 0.0%
fragmentation)
real 0m49.576s
user 0m2.281s
sys 0m0.166s
# memory usage reached max of 7184kb (7MB)
##################################################
# newfs -O1 -b 16384 -f 2048 -i 262144 /dev/ad2s2a
/dev/ad2s2a: 65397.4MB (133933888 sectors) block size 16384, fragment
size 2048
using 294 cylinder groups of 223.02MB, 14273 blks, 896 inodes.
# time fsck -f /dev/ad2s2a
** /dev/ad2s2a
** Last Mounted on
** Phase 1 - Check Blocks and Sizes
** Phase 2 - Check Pathnames
** Phase 3 - Check Connectivity
** Phase 4 - Check Reference Counts
** Phase 5 - Check Cyl groups
2 files, 2 used, 33462291 free (19 frags, 4182784 blocks, 0.0%
fragmentation)
real 0m8.147s
user 0m0.496s
sys 0m0.015s
# memory usage reached max of 7184kb (7MB)
# fill it up
# df -i /mnt
Filesystem 1K-blocks Used Avail Capacity iused ifree %iused Mounted on
/dev/ad2s2a 66924586 4342 61566278 0% 263422 0 100% /mnt
# time fsck -f /dev/ad2s2a
** /dev/ad2s2a
** Last Mounted on /mnt
** Phase 1 - Check Blocks and Sizes
** Phase 2 - Check Pathnames
** Phase 3 - Check Connectivity
** Phase 4 - Check Reference Counts
** Phase 5 - Check Cyl groups
263422 files, 2171 used, 33460122 free (26 frags, 4182512 blocks, 0.0%
fragmentation)
real 0m8.229s
user 0m0.578s
sys 0m0.104s
# memory usage reached max of 8208kb (8MB)
# mount, rm -rf all created files/dirs
# df -i /mnt
Filesystem 1K-blocks Used Avail Capacity iused ifree %iused Mounted on
/dev/ad2s2a 66924586 4 61570616 0% 2 263420 0% /mnt
# time fsck -f /dev/ad2s2a
** /dev/ad2s2a
** Last Mounted on /mnt
** Phase 1 - Check Blocks and Sizes
** Phase 2 - Check Pathnames
** Phase 3 - Check Connectivity
** Phase 4 - Check Reference Counts
** Phase 5 - Check Cyl groups
2 files, 2 used, 33462291 free (19 frags, 4182784 blocks, 0.0%
fragmentation)
real 0m7.797s
user 0m0.473s
sys 0m0.035s
# memory usage reached max of 7184kb (7MB)
##################################################
Full report here:
http://www.googlebit.com/doku.php?id=fsck_times_memory_sizes
Eric
--
------------------------------------------------------------------------
Eric Anderson Sr. Systems Administrator Centaur Technology
An undefined problem has an infinite number of solutions.
------------------------------------------------------------------------
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