Korjavin Ivan's questions

I have a fresh k8s cluster on gke.

Whenever I run kubectl top node gke-data-custom-vm-6-25-0cbae9b9-hrkc I get

Error from server (NotFound): the server could not find the requested resource (get services http:heapster:)

At the same time I have this service:

> kubectl -n kube-system get services
NAME                   TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)         AGE
default-http-backend   NodePort    10.11.241.20    <none>        80:32688/TCP    59d
heapster               ClusterIP   10.11.245.182   <none>        80/TCP          59d
kube-dns               ClusterIP   10.11.240.10    <none>        53/UDP,53/TCP   59d
metrics-server         ClusterIP   10.11.249.26    <none>        443/TCP         59d

and a pod with heapster is running (and I can see it was restarted a lot of times)

 kubectl -n kube-system get pods
NAME                                               READY     STATUS    RESTARTS   AGE
event-exporter-v0.2.3-85644fcdf-kwd6g              2/2       Running   0          16d
fluentd-gcp-scaler-8b674f786-dbrcr                 1/1       Running   0          16d
fluentd-gcp-v3.2.0-2fqgl                           2/2       Running   0          17d
fluentd-gcp-v3.2.0-47586                           2/2       Running   0          17d
fluentd-gcp-v3.2.0-552xm                           2/2       Running   0          16d
heapster-v1.6.0-beta.1-fdc7fd478-8s998             3/3       Running   73         16d

However I can see in logs of heapster-nanny container some errors:

> kubectl logs -n kube-system --tail 10 -f po/heapster-v1.6.0-beta.1-fdc7fd478-8s998 -c heapster-nanny
ERROR: logging before flag.Parse: E0418 23:30:10.075539       1 nanny_lib.go:95] Error while querying apiserver for resources: Get https://10.11.240.1:443/api/v1/namespaces/kube-system/pods/heapster-v1.6.0-beta.1-fdc7fd478-8s998: dial tcp 10.11.240.1:443: getsockopt: connection refused
ERROR: logging before flag.Parse: E0418 23:30:10.971230       1 reflector.go:205] k8s.io/autoscaler/addon-resizer/nanny/kubernetes_client.go:107: Failed to list *v1.Node: Get https://10.11.240.1:443/api/v1/nodes?resourceVersion=0: dial tcp 10.11.240.1:443: getsockopt: connection refused
ERROR: logging before flag.Parse: E0418 23:30:11.972337       1 reflector.go:205] k8s.io/autoscaler/addon-resizer/nanny/kubernetes_client.go:107: Failed to list *v1.Node: Get https://10.11.240.1:443/api/v1/nodes?resourceVersion=0: dial tcp 10.11.240.1:443: getsockopt: connection refused
ERROR: logging before flag.Parse: E0418 23:30:12.973637       1 reflector.go:205] k8s.io/autoscaler/addon-resizer/nanny/kubernetes_client.go:107: Failed to list *v1.Node: Get https://10.11.240.1:443/api/v1/nodes?resourceVersion=0: dial tcp 10.11.240.1:443: getsockopt: connection refused
ERROR: logging before flag.Parse: E0418 23:30:13.975024       1 reflector.go:205] k8s.io/autoscaler/addon-resizer/nanny/kubernetes_client.go:107: Failed to list *v1.Node: Get https://10.11.240.1:443/api/v1/nodes?resourceVersion=0: dial tcp 10.11.240.1:443: getsockopt: connection refused
ERROR: logging before flag.Parse: E0418 23:30:14.976582       1 reflector.go:205] k8s.io/autoscaler/addon-resizer/nanny/kubernetes_client.go:107: Failed to list *v1.Node: Get https://10.11.240.1:443/api/v1/nodes?resourceVersion=0: dial tcp 10.11.240.1:443: getsockopt: connection refused
ERROR: logging before flag.Parse: E0418 23:30:16.063760       1 reflector.go:205] k8s.io/autoscaler/addon-resizer/nanny/kubernetes_client.go:107: Failed to list *v1.Node: Get https://10.11.240.1:443/api/v1/nodes?resourceVersion=0: dial tcp 10.11.240.1:443: getsockopt: connection refused
ERROR: logging before flag.Parse: E0418 23:30:27.065693       1 reflector.go:205] k8s.io/autoscaler/addon-resizer/nanny/kubernetes_client.go:107: Failed to list *v1.Node: Get https://10.11.240.1:443/api/v1/nodes?resourceVersion=0: net/http: TLS handshake timeout
ERROR: logging before flag.Parse: E0418 23:30:30.077159       1 nanny_lib.go:95] Error while querying apiserver for resources: Get https://10.11.240.1:443/api/v1/namespaces/kube-system/pods/heapster-v1.6.0-beta.1-fdc7fd478-8s998: net/http: TLS handshake timeout
ERROR: logging before flag.Parse: E0418 23:30:59.778560       1 reflector.go:205] k8s.io/autoscaler/addon-resizer/nanny/kubernetes_client.go:107: Failed to list *v1.Node: Get https://10.11.240.1:443/api/v1/nodes?resourceVersion=0: dial tcp 10.11.240.1:443: i/o timeout

and also in heapster container

I0423 07:02:10.765134       1 heapster.go:113] Starting heapster on port 8082
W0423 07:16:27.975467       1 manager.go:152] Failed to get all responses in time (got 2/3)
W0423 07:16:43.064110       1 manager.go:107] Failed to get kubelet_summary:10.128.0.49:10255 response in time
W0423 07:20:36.875359       1 manager.go:152] Failed to get all responses in time (got 2/3)
W0423 07:20:44.383790       1 manager.go:107] Failed to get kubelet_summary:10.128.0.49:10255 response in time
W0423 07:22:29.683060       1 manager.go:152] Failed to get all responses in time (got 2/3)
W0423 07:22:40.278962       1 manager.go:107] Failed to get kubelet_summary:10.128.0.49:10255 response in time
W0423 07:31:27.072711       1 manager.go:152] Failed to get all responses in time (got 2/3)
W0423 07:31:54.580031       1 manager.go:107] Failed to get kubelet_summary:10.128.0.49:10255 response in time

How can I fix this?

Any additional info that I should provide?

I have a host which runs a few docker's containers.

This host has a few network interfaces, my goal is make some exposed ports from containers accessible only by certain interfaces, and prevent access from others.

I would like to use host's iptables for that.

But its imposible to do simply with:

iptables -I INPUT -i vlan2 --dport 80 -j DROP

because packets are forwarded by prerouting.

iptables -t nat -L PREROUTING                                                                                                                               2
Chain PREROUTING (policy ACCEPT)
target     prot opt source               destination         
DOCKER     all  --  anywhere             anywhere             ADDRTYPE match dst-type LOCAL

Chain DOCKER (2 references)
target     prot opt source               destination         
DNAT       tcp  --  anywhere             anywhere             tcp dpt:mysql to:172.17.0.2:33066
DNAT       tcp  --  anywhere             anywhere             tcp dpt:http to:172.17.0.4:80

There are two exposed ports 80 and 3306 to different containers, and I want to make it inaccessible from interface vlan2

After I added this:

iptables -I FORWARD -i vlan2 -p tcp --dport 80 -j REJECT

Web server stopped to work, but

iptables -I FORWARD -i vlan2 -p tcp --dport 3306 -j REJECT

don't prevent connection to mysql, I am still able to connect. And tcpdump proves it:

tcpdump -n -i vlan2 port 3306
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on vlan2, link-type EN10MB (Ethernet), capture size 262144 bytes
22:48:13.066636 IP 3.2.2.2.47259 > 1.1.2.3.3306: Flags [S], seq 3619220560, win 29200, options [mss 1460,sackOK,TS val 90183390 ecr 0,nop,wscale 7], length 0
22:48:13.066740 IP 1.1.2.3.3306 > 3.2.2.2.47259: Flags [S.], seq 2743923517, ack 3619220561, win 28960, options [mss 1460,sackOK,TS val 10989883 ecr 90183390,nop,wscale 7], length 0

And I can't understand the difference between these two rules.

How to use host's iptables to prevent access to containers

I have docker container with installed and configured software.

There is no any programm supposed to be started/runned all the time.

What I want - its ability to start some command depending on external events. like:

docker exec mysupercont /path/to/mycommand -bla -for

and

docker exec mysupercont /path/to/myothercommand 

But "exec" impossible when container is stopped, and also this container have some "working" data inside, which used for that commands, so I can't use

docker run ...

each time, because it recreate container from image and destroy my data.

What is the "right" and the "best" way to keep such container runned? Which command I can start inside?

I have special parameter data=/path/to/filename.htm in uri.

Its old and rusty site builded on SSI, and I can't modify it.

Problem is when filename passed as arg_data not exists, page is broken.

I want redirect to 404.htm in this case.

Something like that:

if (!-f $arg_data){
     rewrite ^.*$  /404.htm last;
   } 

But I get:

rewrite or internal redirection cycle while processing "/404.htm

I think its because I didn't check if arg_data exists.

But nginx have not nested if-s.

I tried:

set $data index.htm;                                                                                                                                               
if ($args ~ "data=(.+)") {                                                                                                                                         
    set $data $1;                                                                                                                                                  
}                                                                                                                                                                                                                                                                                                                                          
if (!-f $data) {                                                                                                                                                
    rewrite ^.*$  /404.htm last;                                                                                                                                   
}                   

Idea was set $data to some file which 100% exists, and after that rewrite if data param is passed.

For some reason its give the same error, internal redirection cycle

Looks like I do it in wrong way.

From my FreeBSD boxes, I each day recieve reports daily:

1. File systems used
2. Network interfaces
3. Uptime 4, Mail queue status

security:

1. ipfw deny counters
2. login failures
3. refused connections
4. kernel log messages

Just wonder, what if exists some config_templates/package for my debian boxes, which do the same?

I have nginx redirect like:

server {                                                                                                         
      listen       127.0.0.1:80;                                                                                 
      server_name  myname.local
      location / {                                                                                               
          proxy_pass http://m1.local:8080;                                                               
          }                                                                                                      
    }                                                                                                            
}   

Works good.

But after ip address for m1.local was changed - nginx start to return "bad gateway".

Looks like it has caching ip address for m1.local.

nslookup m1.local from nginx computer show right value, and restart nginx repair the situation.

How to say nginx that it shouldn't cache ip's for dns name?

I use this command for test my html pages for errors:

find . -iname '*html' -type f -print -exec /usr/local/bin/tidy -q -e {} \;

And I want to get exit code > 0 if any errors was founded by tidy.

find always return me 0.

Is there any way to sums exit code from tidy, and return it from find or any other wrapper script?

I have a lot of backups, like:

backup-20130528_054504_mysql.tar.gz, 
bill_db_201305290130.BAK.bz2,
etc_20130412.tbz

This is full backups which done each day.

Before today, I have a cron task with a command line like this:

/usr/bin/find /media/backups -ctime +7 -delete

But it was the bad idea.

One server stopped do new backups (filesystem was full) more than 7 days ago, and all old backups was deleted by cron.

Probably I need a new script as replacement for this "find -ctime", which will hold some old backups anyway.

All my backup files have names {unique_prefix}YYYYMMDD...

I want something like :

• one backup for each year before last year
• one backup for each month of last year
• 4 backup for each week of previous month
• and 7 backups for last 7 days.

for each {unique_prefix}.

All this files are downloaded to my server by cron via rsync, ssh , etc..

I dislike reinvent the wheel, and pretty sure that is a typical task.

Please, point me to the solution.

I have FreeBSD router:

#uname
9.1-STABLE FreeBSD 9.1-STABLE #0: Fri Jan 18 16:20:47 YEKT 2013

It's a powerful computer with a lot of memory

#top -S
last pid: 45076;  load averages:  1.54,  1.46,  1.29                                      up 0+21:13:28  19:23:46
84 processes:  2 running, 81 sleeping, 1 waiting
CPU:  3.1% user,  0.0% nice, 32.1% system,  5.3% interrupt, 59.5% idle
Mem: 390M Active, 1441M Inact, 785M Wired, 799M Buf, 5008M Free
Swap: 8192M Total, 8192M Free

  PID USERNAME    THR PRI NICE   SIZE    RES STATE   C   TIME   WCPU COMMAND
   11 root          4 155 ki31     0K    64K RUN     3  71.4H 254.83% idle
   13 root          4 -16    -     0K    64K sleep   0 101:52 103.03% ng_queue
    0 root         14 -92    0     0K   224K -       2 229:44 16.55% kernel
   12 root         17 -84    -     0K   272K WAIT    0 213:32 15.67% intr
40228 root          1  22    0 51060K 25084K select  0  20:27  1.66% snmpd
15052 root          1  52    0   104M 22204K select  2   4:36  0.98% mpd5
   19 root          1  16    -     0K    16K syncer  1   0:48  0.20% syncer

Its tasks are: NAT via ng_nat and PPPoE server via mpd5.

Traffic through - about 300Mbit/s, about 40kpps at peak. Pppoe sessions created - 350 max.

ng_nat is configured by by the script:

 /usr/sbin/ngctl -f- <<-EOF                                            

             mkpeer ipfw: nat %s out                                                                               
             name ipfw:%s %s                                                                                       
             connect ipfw: %s: %s in                                                                               
             msg %s: setaliasaddr 1.1.%s

There are 20 such ng_nat nodes, with about 150 clients.

Sometimes, the traffic via nat stops. When this happens vmstat reports a lot of FAIL counts

vmstat -z | grep -i netgraph
ITEM                   SIZE  LIMIT     USED     FREE      REQ FAIL SLEEP
NetGraph items:          72,  10266,       1,     376,39178965,   0,   0
NetGraph data items:     72,  10266,       9,   10257,2327948820,2131611,4033

I was tried increase

net.graph.maxdata=10240                                                                                           
net.graph.maxalloc=10240

but this doesn't work.

It's a new problem (1-2 week). The configuration had been working well for about 5 months and no configuration changes were made leading up to the problems starting.

In the last few weeks we have slightly increased traffic (from 270 to 300 mbits) and little more pppoe sessions (300->350).

Help me please, how to find and solve my problem?

Upd: Info about network cards:

# pciconf -lv | grep -B3 network   
em0@pci0:0:25:0:        class=0x020000 card=0x35788086 chip=0x15028086 rev=0x05 hdr=0x00
    vendor     = 'Intel Corporation'
    device     = '82579LM Gigabit Network Connection'
    class      = network
--
em1@pci0:2:0:0: class=0x020000 card=0x35788086 chip=0x10d38086 rev=0x00 hdr=0x00
    vendor     = 'Intel Corporation'
    device     = '82574L Gigabit Network Connection'
    class      = network

UPD: There is 2 "top" output https://gist.github.com/korjavin/9190181

when I swith net.isr.dispatch to hybrid. After this, I have tons of mpd processes (don't know why) and one CPU to 100% of interrupt, and after 10 minutes of work it was rebooted, due to big packet lost.

UPD: Happened again There is "top" output before reboot and after https://gist.github.com/korjavin/9254734

looks like problem in ng_queue proccess, which eating CPU to much. Since my first post, there much more sessions and traffics. About 400 pppoe , and 450Mbit/s

Today I saw this record in my log files:

dhcpd: DHCPDISCOVER from ff:ff:ff:ff:ff:ff via vlan400: network 40.60.100.10/24: no free leases                                                                                                              
dhcpd: DHCPDISCOVER from ff:ff:ff:ff:ff:ff via vlan300: network 100.100.120.0/24: no free leases                   

And so on, on all VLANs connected to the same ethernet card em1.

I am 99% sure that I have no devices on these VLANs which are able to send DHCP requests.

Also ff:ff:ff is a strange MAC.

So, my question is: is it something bad? Some errors on the ethernet-card or switch or something?

I have a freebsd 9.0 router with 250-300Mbit/s traffic, and need to filter small list of pages (http.request.uri).

I do not care about tor, anonymizers, proxy etc. Just prevent direct access from my network to this pages.

How? Only redirect http to squid or any other http-proxy?

I know about tcpdump -ddd and bpf netgraph node. But http is to hard for me.

I update one my freebsd box to 9-stable (totally new installation) and install net-snmp for monitoring.

uname -r 
9.1-PRERELEASE

pkg_info net-snmp-5.7.1_7 
Information for net-snmp-5.7.1_7:

Comment:
An extendable SNMP implementation
....


cat /var/db/ports/net-snmp/options 
# This file is auto-generated by 'make config'.
# Options for net-snmp-5.7.1_7
_OPTIONS_READ=net-snmp-5.7.1_7
_FILE_COMPLETE_OPTIONS_LIST= IPV6 MFD_REWRITES PERL PERL_EMBEDDED PYTHON DUMMY TKMIB DMALLOC MYSQL AX_SOCKONLY UNPRIVILEGED
OPTIONS_FILE_UNSET+=IPV6
OPTIONS_FILE_UNSET+=MFD_REWRITES
OPTIONS_FILE_SET+=PERL
OPTIONS_FILE_SET+=PERL_EMBEDDED
OPTIONS_FILE_UNSET+=PYTHON
OPTIONS_FILE_SET+=DUMMY
OPTIONS_FILE_UNSET+=TKMIB
OPTIONS_FILE_SET+=DMALLOC
OPTIONS_FILE_UNSET+=MYSQL
OPTIONS_FILE_UNSET+=AX_SOCKONLY
OPTIONS_FILE_UNSET+=UNPRIVILEGED

I have about 500 vlan on this machine, and collect info about interface through snmpd to 2 different software, zabbix and cacti.

And both of them plot the graphs with blank fields.

I tryed change polling time in zabbix, from 15, sec to 30,60,90,120,10. And anyway i have blank fields.

snmpd.conf is empty - only a access controls.

This configuration worked fine on freebsd 8.

Where is my fault? How fix this graphs?

UPD: Changing pooling time, switch off one of agent, doesnt help. I look at zabbix log (recieved data from snmpd) and see that: sorry for russian locale, just look at numbers:

and thats is not true, as my "iftop" show speed was about 90Mbits, but snmpd return 2Mbits.

I understand that snmpd doesnt return speed, it return just a counter. But how its possible? why 2Mbit/s ?

I tryed recompile snmpd with 64-bit counters, and without it. In both variants this blank fields present.

So i think its my OS (freebsd) doesnt update interface counters well.

I still collect tcpdump for found this request/response. But have problem with that, to much trash.

UPD2: I decrypt tcpdump-ed file, and public this as google doc at gdocfile

Timediff looks strange.. Like zabbix sometimes "forget" do request, and then do twice at row, ehh

UPD3: I parse log from command "while true; do netstat -bin -I vlan4008 >> /var/log/netstat; sleep 300; done" and load as google docs, and add formula for speed : link

Looks like all counters in OS are good. Now i think problem in : 1. zabbix get request twice at row (and what about cacti) 2. snmpd use counter32

I set this lines in my rc.conf:

firewall_enable="YES"
firewall_type="/etc/ipfw.rules"

cat /etc/ipfw.rules

add 02020 deny ip from table(10) to any
add 02030 deny ip from table(11) to any dst-port 25

...

But after reboot, ipfw show :

00100 allow ip from any to any via lo0
00200 deny ip from any to 127.0.0.0/8
00300 deny ip from 127.0.0.0/8 to any
00400 deny ip from any to ::1
00500 deny ip from ::1 to any
00600 allow ipv6-icmp from :: to ff02::/16
00700 allow ipv6-icmp from fe80::/10 to fe80::/10
00800 allow ipv6-icmp from fe80::/10 to ff02::/16
00900 allow ipv6-icmp from any to any ip6 icmp6types 1
01000 allow ipv6-icmp from any to any ip6 icmp6types 2,135,136
 ... after that, my rules

But i have not this lines about ip6 in my ipfw.rules.

How to disable this useless rules?

I have network based on stupid hubs.

And freebsd router in center of this network.

Today i see in 'systat -vmstat' :
Interrupts 8005 em1:rx 0

That was a loop on one hub.

Is there any way to detect this and email me if this happent?

I have Dell PowerEdge 1950 with hardware raid Perc 5/i.

I want use software raid md/lvm.

Is any way to totally disable this raid and see "raw" sata disks?

I play alot with BIOS , enable SATA, disable raid controller, but nothing happents, i not see the disks.

Any advice?

On my freebsd box i have snmpd daemon from net-snmp-5.5_4 packet.

In snmpd.conf file i have:

extend .1.3.6.1.4.1.2021.2 inpt /usr/bin/perl /usr/local/etc/snmp/mpdinput.pl

where mpdinput.pl my script which return input-octets from some mpd5-ng network interface.

Cacti reading this value and plot such graphs:

I added red lines to graph.

In marked places snmpd cache the result and return prev values, thats why rrdtool plot zero activity. And its a problem for me.

How to prevent caching result in snmpd?

On my freebsd box

$uname -rms
FreeBSD 7.2-RELEASE-p5 i386

hard disk want to die. smartd daemon write in log:

Mar 29 21:25:04  smartd[935]: Device: /dev/ad7, 10 Currently unreadable (pending) sectors                     
Mar 29 21:25:04  smartd[935]: Device: /dev/ad7, 10 Offline uncorrectable sectors       

I insert new disk (ad5), and have this plan:

1. create gmirror raid
2. insert ad5 into raid
3. after sync remove ad7 from raid
4. disconect ad7 disk.

But looks like sync never will be done. I always see:

mirror/gm1  DEGRADED  ad5s1e (79%)
                      ad7s1e

I tryed deactivate/activate ad5s1e. I tryed gmirror rebuild gm1 ad5s1e . I was rebooted into single mode. 79% is always barrier.

How to finish this sync?

upd:

One more try to rebuild, and i see this in log:

Mar 30 01:33:03  kernel: ad7: FAILURE - READ_DMA48 status=51<READY,DSC,ERROR> error=40<UNCORRECTABLE> LBA=372929727
Mar 30 01:33:03  kernel: GEOM_MIRROR: Synchronization request failed (error=5). mirror/gm1[READ(offset=177321017344, length=131072)]
Mar 30 01:33:11  kernel: ad7: FAILURE - READ_DMA48 status=51<READY,DSC,ERROR> error=40<UNCORRECTABLE> LBA=372948031
Mar 30 01:33:11  kernel: GEOM_MIRROR: Synchronization request failed (error=5). mirror/gm1[READ(offset=177330454528, length=131072)]

after this 79% and frozen again.

Where is right place for sysctl redefined values?

I have:

> uname -a
Linux note 3.1.0-1-amd64 #1 SMP Tue Jan 10 05:01:58 UTC 2012 x86_64 GNU/Linux

> cat /etc/debian_version 
wheezy/sid


> tail -n 2 /etc/sysctl.conf   
#
net.ipv6.bindv6only=0

But after each reboot net.ipv6.bindv6only still 1

I have cacti with a lot of graphs (interface statistics) and I need show the difference between two of them. Something like traffic=traffic1-traffic2 where traffic1 and traffic2 are interfaces on two separate switches.

Is it possible?

Not sure, is this right site for this Q, but let me try

Last time i have problem with hard disk. Sometimes its do strange sound, and i get it from logs:

$dmesg | grep ata4

[29409.945516] ata4.00: exception Emask 0x10 SAct 0xf SErr 0x90202 action 0xe frozen

[29409.945529] ata4.00: irq_stat 0x00400000, PHY RDY changed

[29409.945538] ata4: SError: { RecovComm Persist PHYRdyChg 10B8B }

[29409.945546] ata4.00: failed command: READ FPDMA QUEUED

[29409.945562] ata4.00: cmd 60/30:00:56:22:5f/00:00:00:00:00/40 tag 0 ncq 24576 
in
[29409.945573] ata4.00: status: { DRDY }

[29409.945580] ata4.00: failed command: READ FPDMA QUEUED

[29409.945594] ata4.00: cmd 60/18:08:8e:22:5f/00:00:00:00:00/40 tag 1 ncq 12288 
in
[29409.945605] ata4.00: status: { DRDY }

[29409.945611] ata4.00: failed command: READ FPDMA QUEUED

[29409.945625] ata4.00: cmd 60/08:10:46:02:66/00:00:00:00:00/40 tag 2 ncq 4096 
in
[29409.945635] ata4.00: status: { DRDY }

[29409.945641] ata4.00: failed command: READ FPDMA QUEUED

[29409.945656] ata4.00: cmd 60/80:18:ee:04:66/00:00:00:00:00/40 tag 3 ncq 65536 
in
[29409.945666] ata4.00: status: { DRDY }

[29409.945679] ata4: hard resetting link

[29413.976083] ata4: softreset failed (device not ready)

[29413.976097] ata4: applying SB600 PMP SRST workaround and retrying

[29414.148070] ata4: SATA link up 3.0 Gbps (SStatus 123 SControl 300)

[29414.184986] ata4.00: SB600 AHCI: limiting to 255 sectors per cmd

[29414.243280] ata4.00: SB600 AHCI: limiting to 255 sectors per cmd

[29414.243292] ata4.00: configured for UDMA/133

[29414.243324] ata4: EH complete

[680674.804563] ata4: exception Emask 0x50 SAct 0x0 SErr 0x90a02 action 0xe 
frozen
[680674.804575] ata4: irq_stat 0x00400000, PHY RDY changed

[680674.804584] ata4: SError: { RecovComm Persist HostInt PHYRdyChg 10B8B }

[680674.804603] ata4: hard resetting link

[680678.840561] ata4: softreset failed (device not ready)

Is this ata4 sata hard drive dead? Must i change it ASAP ? Need I specify more info?