May be some one can spot a new light,
1. Only SSD-cache OSDs affected by this issue
2. Total cache OSD count is 12x60GiB, backend filesystem is ext4
3. I have created 2 cache tier pools with replica size=3 on that OSD,
both with pg_num:400, pgp_num:400
4. There was a crush ruleset:
superuser@admin:~$ ceph osd crush rule dump ssd
{ "rule_id": 3,
"rule_name": "ssd",
"ruleset": 3,
"type": 1,
"min_size": 1,
"max_size": 10,
"steps": [
{ "op": "take",
"item": -21,
"item_name": "ssd"},
{ "op": "chooseleaf_firstn",
"num": 0,
"type": "disktype"},
{ "op": "emit"}]}
for gathering all SSD OSDs from all nodes by *disktype*
I guess there may be a lot of *directories* that was created on
filesystem for organizing placement groups, can that cause that very big
amount of inodes occupied by directory records?
24.03.2015 16:52, Gregory Farnum пишет:
On Tue, Mar 24, 2015 at 12:13 AM, Christian Balzer <chibi@xxxxxxx> wrote:
On Tue, 24 Mar 2015 09:41:04 +0300 Kamil Kuramshin wrote:
Yes I read it and do no not understand what you mean when say *verify
this*? All 3335808 inodes are definetly files and direcories created by
ceph OSD process:
What I mean is how/why did Ceph create 3+ million files, where in the tree
are they actually or are they evenly distributed in the respective PG
sub-directories.
Or to ask it differently, how large is your cluster (how many OSDs,
objects), in short the output of "ceph -s".
If cache-tiers actually are reserving each object that exists on the
backing store (even if there isn't data in it yet on the cache tier) and
your cluster is large enough, it might explain this.
Nope. As you've said, this doesn't make any sense unless the objects
are all ludicrously small (and you can't actually get 10-byte objects
in Ceph; the names alone tend to be bigger than that) or something
else is using up inodes.
And that should both be mentioned and precautions to not run out of inodes
should be made by the Ceph code.
If not, this may be a bug after all.
Would be nice if somebody from the Ceph devs could have gander at this.
Christian
*tune2fs 1.42.5 (29-Jul-2012)*
Filesystem volume name: <none>
Last mounted on: /var/lib/ceph/tmp/mnt.05NAJ3
Filesystem UUID: e4dcca8a-7b68-4f60-9b10-c164dc7f9e33
Filesystem magic number: 0xEF53
Filesystem revision #: 1 (dynamic)
Filesystem features: has_journal ext_attr resize_inode dir_index
filetype extent flex_bg sparse_super large_file huge_file uninit_bg
dir_nlink extra_isize
Filesystem flags: signed_directory_hash
Default mount options: user_xattr acl
Filesystem state: clean
Errors behavior: Continue
Filesystem OS type: Linux
*Inode count: 3335808*
Block count: 13342945
Reserved block count: 667147
Free blocks: 5674105
*Free inodes: 0*
First block: 0
Block size: 4096
Fragment size: 4096
Reserved GDT blocks: 1020
Blocks per group: 32768
Fragments per group: 32768
Inodes per group: 8176
Inode blocks per group: 511
Flex block group size: 16
Filesystem created: Fri Feb 20 16:44:25 2015
Last mount time: Tue Mar 24 09:33:19 2015
Last write time: Tue Mar 24 09:33:27 2015
Mount count: 7
Maximum mount count: -1
Last checked: Fri Feb 20 16:44:25 2015
Check interval: 0 (<none>)
Lifetime writes: 4116 GB
Reserved blocks uid: 0 (user root)
Reserved blocks gid: 0 (group root)
First inode: 11
Inode size: 256
Required extra isize: 28
Desired extra isize: 28
Journal inode: 8
Default directory hash: half_md4
Directory Hash Seed: 148ee5dd-7ee0-470c-a08a-b11c318ff90b
Journal backup: inode blocks
*fsck.ext4 /dev/sda1*
e2fsck 1.42.5 (29-Jul-2012)
/dev/sda1: clean, 3335808/3335808 files, 7668840/13342945 blocks
23.03.2015 17:09, Christian Balzer пишет:
On Mon, 23 Mar 2015 15:26:07 +0300 Kamil Kuramshin wrote:
Yes, I understand that.
The initial purpose of first email was just an advise for new comers.
My fault was in that I was selected ext4 for SSD disks as backend.
But I did not foresee that inode number can reach its limit before
the free space :)
And maybe there must be some sort of warning not only for free space
in MiBs(GiBs,TiBs) and there must be dedicated warning about free
inodes for filesystems with static inode allocation like ext4.
Because if OSD reach inode limit it becames totally unusable and
immediately goes down, and from that moment there is no way to start
it!
While all that is true and should probably be addressed, please re-read
what I wrote before.
With the 3.3 million inodes used and thus likely as many files (did you
verify this?) and 4MB objects that would make something in the 12TB
ballpark area.
Something very very strange and wrong is going on with your cache tier.
Christian
23.03.2015 13:42, Thomas Foster пишет:
You could fix this by changing your block size when formatting the
mount-point with the mkfs -b command. I had this same issue when
dealing with the filesystem using glusterfs and the solution is to
either use a filesystem that allocates inodes automatically or change
the block size when you build the filesystem. Unfortunately, the
only way to fix the problem that I have seen is to reformat
On Mon, Mar 23, 2015 at 5:51 AM, Kamil Kuramshin
<kamil.kuramshin@xxxxxxxx <mailto:kamil.kuramshin@xxxxxxxx>> wrote:
In my case there was cache pool for ec-pool serving RBD-images,
and object size is 4Mb, and client was an /kernel-rbd /client
each SSD disk is 60G disk, 2 disk per node, 6 nodes in total =
12 OSDs in total
23.03.2015 12:00, Christian Balzer пишет:
Hello,
This is rather confusing, as cache-tiers are just normal
OSDs/pools and thus should have Ceph objects of around 4MB in size
by default.
This is matched on what I see with Ext4 here (normal OSD, not a
cache tier):
---
size:
/dev/sde1 2.7T 204G 2.4T 8% /var/lib/ceph/osd/ceph-0
inodes:
/dev/sde1 183148544 55654 183092890
1% /var/lib/ceph/osd/ceph-0 ---
On a more fragmented cluster I see a 5:1 size to inode ratio.
I just can't fathom how there could be 3.3 million inodes (and
thus a close number of files) using 30G, making the average file
size below 10 Bytes.
Something other than your choice of file system is probably at
play here.
How fragmented are those SSDs?
What's your default Ceph object size?
Where _are_ those 3 million files in that OSD, are they
actually in the object files like:
-rw-r--r-- 1 root root 4194304 Jan 9
15:27 /var/lib/ceph/osd/ceph-0/current/3.117_head/DIR_7/DIR_1/DIR_5/rb.0.23a8f.238e1f29.000000027632__head_C4F3D517__3
What's your use case, RBD, CephFS, RadosGW?
Regards,
Christian
On Mon, 23 Mar 2015 10:32:55 +0300 Kamil Kuramshin wrote:
Recently got a problem with OSDs based on SSD disks used in
cache tier for EC-pool
superuser@node02:~$ df -i
Filesystem Inodes IUsed *IFree* IUse%
Mounted on <...>
/dev/sdb1 3335808 3335808 *0* 100%
/var/lib/ceph/osd/ceph-45
/dev/sda1 3335808 3335808 *0* 100%
/var/lib/ceph/osd/ceph-46
Now that OSDs are down on each ceph-node and cache tiering is
not working.
superuser@node01:~$ sudo tail /var/log/ceph/ceph-osd.45.log
2015-03-23 10:04:23.631137 7fb105345840 0 ceph version 0.87.1
(283c2e7cfa2457799f534744d7d549f83ea1335e), process ceph-osd,
pid 1453465 2015-03-23 10:04:23.640676 7fb105345840 0
filestore(/var/lib/ceph/osd/ceph-45) backend generic (magic
0xef53) 2015-03-23 10:04:23.640735 7fb105345840 -1
genericfilestorebackend(/var/lib/ceph/osd/ceph-45)
detect_features: unable to
create /var/lib/ceph/osd/ceph-45/fiemap_test: (28) No space left on
device 2015-03-23 10:04:23.640763 7fb105345840 -1
filestore(/var/lib/ceph/osd/ceph-45) _detect_fs:
detect_features error: (28) No space left on device
2015-03-23 10:04:23.640772 7fb105345840 -1
filestore(/var/lib/ceph/osd/ceph-45) FileStore::mount : error
in _detect_fs: (28) No space left on device
2015-03-23 10:04:23.640783 7fb105345840 -1 ** ERROR: error
converting store /var/lib/ceph/osd/ceph-45: (28) *No space left on
device*
In the same time*df -h *is confusing:
superuser@node01:~$ df -h
Filesystem Size Used *Avail* Use% Mounted on
<...>
/dev/sda1 50G 29G *20G*
60% /var/lib/ceph/osd/ceph-45 /dev/sdb1 50G
27G *21G* 56% /var/lib/ceph/osd/ceph-46
Filesystem used on affected OSDs is EXt4. All OSDs are
deployed with ceph-deploy:
$ ceph-deploy osd create --zap-disk --fs-type ext4
<node-name>:<device>
Help me out what it was just test deployment and all EC-pool
data was lost since I /can't start OSDs/ and ceph cluster/becames
degraded /until I removed all affected tiered pools (cache & EC)
So this is just my observation of what kind of problems can be
faced if you choose wrong Filesystem for OSD backend.
And now I *strongly* recommend you to choose*XFS* or *Btrfs*
filesystems because both are supporting dynamic inode allocation
and this problem can't arise with them.
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--
Christian Balzer Network/Systems Engineer
chibi@xxxxxxx Global OnLine Japan/Fusion Communications
http://www.gol.com/
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